-
Notifications
You must be signed in to change notification settings - Fork 10.8k
/
CGExprAgg.cpp
2242 lines (1936 loc) · 84.2 KB
/
CGExprAgg.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
//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===//
//
// 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 contains code to emit Aggregate Expr nodes as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CGCXXABI.h"
#include "CGObjCRuntime.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "ConstantEmitter.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/StmtVisitor.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
using namespace clang;
using namespace CodeGen;
//===----------------------------------------------------------------------===//
// Aggregate Expression Emitter
//===----------------------------------------------------------------------===//
namespace llvm {
extern cl::opt<bool> EnableSingleByteCoverage;
} // namespace llvm
namespace {
class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
CodeGenFunction &CGF;
CGBuilderTy &Builder;
AggValueSlot Dest;
bool IsResultUnused;
AggValueSlot EnsureSlot(QualType T) {
if (!Dest.isIgnored()) return Dest;
return CGF.CreateAggTemp(T, "agg.tmp.ensured");
}
void EnsureDest(QualType T) {
if (!Dest.isIgnored()) return;
Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured");
}
// Calls `Fn` with a valid return value slot, potentially creating a temporary
// to do so. If a temporary is created, an appropriate copy into `Dest` will
// be emitted, as will lifetime markers.
//
// The given function should take a ReturnValueSlot, and return an RValue that
// points to said slot.
void withReturnValueSlot(const Expr *E,
llvm::function_ref<RValue(ReturnValueSlot)> Fn);
public:
AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest, bool IsResultUnused)
: CGF(cgf), Builder(CGF.Builder), Dest(Dest),
IsResultUnused(IsResultUnused) { }
//===--------------------------------------------------------------------===//
// Utilities
//===--------------------------------------------------------------------===//
/// EmitAggLoadOfLValue - Given an expression with aggregate type that
/// represents a value lvalue, this method emits the address of the lvalue,
/// then loads the result into DestPtr.
void EmitAggLoadOfLValue(const Expr *E);
enum ExprValueKind {
EVK_RValue,
EVK_NonRValue
};
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
/// SrcIsRValue is true if source comes from an RValue.
void EmitFinalDestCopy(QualType type, const LValue &src,
ExprValueKind SrcValueKind = EVK_NonRValue);
void EmitFinalDestCopy(QualType type, RValue src);
void EmitCopy(QualType type, const AggValueSlot &dest,
const AggValueSlot &src);
void EmitArrayInit(Address DestPtr, llvm::ArrayType *AType, QualType ArrayQTy,
Expr *ExprToVisit, ArrayRef<Expr *> Args,
Expr *ArrayFiller);
AggValueSlot::NeedsGCBarriers_t needsGC(QualType T) {
if (CGF.getLangOpts().getGC() && TypeRequiresGCollection(T))
return AggValueSlot::NeedsGCBarriers;
return AggValueSlot::DoesNotNeedGCBarriers;
}
bool TypeRequiresGCollection(QualType T);
//===--------------------------------------------------------------------===//
// Visitor Methods
//===--------------------------------------------------------------------===//
void Visit(Expr *E) {
ApplyDebugLocation DL(CGF, E);
StmtVisitor<AggExprEmitter>::Visit(E);
}
void VisitStmt(Stmt *S) {
CGF.ErrorUnsupported(S, "aggregate expression");
}
void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
void VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
Visit(GE->getResultExpr());
}
void VisitCoawaitExpr(CoawaitExpr *E) {
CGF.EmitCoawaitExpr(*E, Dest, IsResultUnused);
}
void VisitCoyieldExpr(CoyieldExpr *E) {
CGF.EmitCoyieldExpr(*E, Dest, IsResultUnused);
}
void VisitUnaryCoawait(UnaryOperator *E) { Visit(E->getSubExpr()); }
void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
return Visit(E->getReplacement());
}
void VisitConstantExpr(ConstantExpr *E) {
EnsureDest(E->getType());
if (llvm::Value *Result = ConstantEmitter(CGF).tryEmitConstantExpr(E)) {
Address StoreDest = Dest.getAddress();
// The emitted value is guaranteed to have the same size as the
// destination but can have a different type. Just do a bitcast in this
// case to avoid incorrect GEPs.
if (Result->getType() != StoreDest.getType())
StoreDest = StoreDest.withElementType(Result->getType());
CGF.EmitAggregateStore(Result, StoreDest,
E->getType().isVolatileQualified());
return;
}
return Visit(E->getSubExpr());
}
// l-values.
void VisitDeclRefExpr(DeclRefExpr *E) { EmitAggLoadOfLValue(E); }
void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
void VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
EmitAggLoadOfLValue(E);
}
void VisitPredefinedExpr(const PredefinedExpr *E) {
EmitAggLoadOfLValue(E);
}
// Operators.
void VisitCastExpr(CastExpr *E);
void VisitCallExpr(const CallExpr *E);
void VisitStmtExpr(const StmtExpr *E);
void VisitBinaryOperator(const BinaryOperator *BO);
void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO);
void VisitBinAssign(const BinaryOperator *E);
void VisitBinComma(const BinaryOperator *E);
void VisitBinCmp(const BinaryOperator *E);
void VisitCXXRewrittenBinaryOperator(CXXRewrittenBinaryOperator *E) {
Visit(E->getSemanticForm());
}
void VisitObjCMessageExpr(ObjCMessageExpr *E);
void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
EmitAggLoadOfLValue(E);
}
void VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E);
void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
void VisitChooseExpr(const ChooseExpr *CE);
void VisitInitListExpr(InitListExpr *E);
void VisitCXXParenListOrInitListExpr(Expr *ExprToVisit, ArrayRef<Expr *> Args,
FieldDecl *InitializedFieldInUnion,
Expr *ArrayFiller);
void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
llvm::Value *outerBegin = nullptr);
void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E);
void VisitNoInitExpr(NoInitExpr *E) { } // Do nothing.
void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
CodeGenFunction::CXXDefaultArgExprScope Scope(CGF, DAE);
Visit(DAE->getExpr());
}
void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
CodeGenFunction::CXXDefaultInitExprScope Scope(CGF, DIE);
Visit(DIE->getExpr());
}
void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
void VisitCXXConstructExpr(const CXXConstructExpr *E);
void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
void VisitLambdaExpr(LambdaExpr *E);
void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E);
void VisitExprWithCleanups(ExprWithCleanups *E);
void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); }
void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E);
void VisitOpaqueValueExpr(OpaqueValueExpr *E);
void VisitPseudoObjectExpr(PseudoObjectExpr *E) {
if (E->isGLValue()) {
LValue LV = CGF.EmitPseudoObjectLValue(E);
return EmitFinalDestCopy(E->getType(), LV);
}
AggValueSlot Slot = EnsureSlot(E->getType());
bool NeedsDestruction =
!Slot.isExternallyDestructed() &&
E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct;
if (NeedsDestruction)
Slot.setExternallyDestructed();
CGF.EmitPseudoObjectRValue(E, Slot);
if (NeedsDestruction)
CGF.pushDestroy(QualType::DK_nontrivial_c_struct, Slot.getAddress(),
E->getType());
}
void VisitVAArgExpr(VAArgExpr *E);
void VisitCXXParenListInitExpr(CXXParenListInitExpr *E);
void VisitCXXParenListOrInitListExpr(Expr *ExprToVisit, ArrayRef<Expr *> Args,
Expr *ArrayFiller);
void EmitInitializationToLValue(Expr *E, LValue Address);
void EmitNullInitializationToLValue(LValue Address);
// case Expr::ChooseExprClass:
void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); }
void VisitAtomicExpr(AtomicExpr *E) {
RValue Res = CGF.EmitAtomicExpr(E);
EmitFinalDestCopy(E->getType(), Res);
}
void VisitPackIndexingExpr(PackIndexingExpr *E) {
Visit(E->getSelectedExpr());
}
};
} // end anonymous namespace.
//===----------------------------------------------------------------------===//
// Utilities
//===----------------------------------------------------------------------===//
/// EmitAggLoadOfLValue - Given an expression with aggregate type that
/// represents a value lvalue, this method emits the address of the lvalue,
/// then loads the result into DestPtr.
void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
LValue LV = CGF.EmitLValue(E);
// If the type of the l-value is atomic, then do an atomic load.
if (LV.getType()->isAtomicType() || CGF.LValueIsSuitableForInlineAtomic(LV)) {
CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest);
return;
}
EmitFinalDestCopy(E->getType(), LV);
}
/// True if the given aggregate type requires special GC API calls.
bool AggExprEmitter::TypeRequiresGCollection(QualType T) {
// Only record types have members that might require garbage collection.
const RecordType *RecordTy = T->getAs<RecordType>();
if (!RecordTy) return false;
// Don't mess with non-trivial C++ types.
RecordDecl *Record = RecordTy->getDecl();
if (isa<CXXRecordDecl>(Record) &&
(cast<CXXRecordDecl>(Record)->hasNonTrivialCopyConstructor() ||
!cast<CXXRecordDecl>(Record)->hasTrivialDestructor()))
return false;
// Check whether the type has an object member.
return Record->hasObjectMember();
}
void AggExprEmitter::withReturnValueSlot(
const Expr *E, llvm::function_ref<RValue(ReturnValueSlot)> EmitCall) {
QualType RetTy = E->getType();
bool RequiresDestruction =
!Dest.isExternallyDestructed() &&
RetTy.isDestructedType() == QualType::DK_nontrivial_c_struct;
// If it makes no observable difference, save a memcpy + temporary.
//
// We need to always provide our own temporary if destruction is required.
// Otherwise, EmitCall will emit its own, notice that it's "unused", and end
// its lifetime before we have the chance to emit a proper destructor call.
bool UseTemp = Dest.isPotentiallyAliased() || Dest.requiresGCollection() ||
(RequiresDestruction && !Dest.getAddress().isValid());
Address RetAddr = Address::invalid();
Address RetAllocaAddr = Address::invalid();
EHScopeStack::stable_iterator LifetimeEndBlock;
llvm::Value *LifetimeSizePtr = nullptr;
llvm::IntrinsicInst *LifetimeStartInst = nullptr;
if (!UseTemp) {
RetAddr = Dest.getAddress();
} else {
RetAddr = CGF.CreateMemTemp(RetTy, "tmp", &RetAllocaAddr);
llvm::TypeSize Size =
CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy));
LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAllocaAddr.getPointer());
if (LifetimeSizePtr) {
LifetimeStartInst =
cast<llvm::IntrinsicInst>(std::prev(Builder.GetInsertPoint()));
assert(LifetimeStartInst->getIntrinsicID() ==
llvm::Intrinsic::lifetime_start &&
"Last insertion wasn't a lifetime.start?");
CGF.pushFullExprCleanup<CodeGenFunction::CallLifetimeEnd>(
NormalEHLifetimeMarker, RetAllocaAddr, LifetimeSizePtr);
LifetimeEndBlock = CGF.EHStack.stable_begin();
}
}
RValue Src =
EmitCall(ReturnValueSlot(RetAddr, Dest.isVolatile(), IsResultUnused,
Dest.isExternallyDestructed()));
if (!UseTemp)
return;
assert(Dest.isIgnored() || Dest.getPointer() != Src.getAggregatePointer());
EmitFinalDestCopy(E->getType(), Src);
if (!RequiresDestruction && LifetimeStartInst) {
// If there's no dtor to run, the copy was the last use of our temporary.
// Since we're not guaranteed to be in an ExprWithCleanups, clean up
// eagerly.
CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst);
CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAllocaAddr.getPointer());
}
}
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src) {
assert(src.isAggregate() && "value must be aggregate value!");
LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddress(), type);
EmitFinalDestCopy(type, srcLV, EVK_RValue);
}
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src,
ExprValueKind SrcValueKind) {
// If Dest is ignored, then we're evaluating an aggregate expression
// in a context that doesn't care about the result. Note that loads
// from volatile l-values force the existence of a non-ignored
// destination.
if (Dest.isIgnored())
return;
// Copy non-trivial C structs here.
LValue DstLV = CGF.MakeAddrLValue(
Dest.getAddress(), Dest.isVolatile() ? type.withVolatile() : type);
if (SrcValueKind == EVK_RValue) {
if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct) {
if (Dest.isPotentiallyAliased())
CGF.callCStructMoveAssignmentOperator(DstLV, src);
else
CGF.callCStructMoveConstructor(DstLV, src);
return;
}
} else {
if (type.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) {
if (Dest.isPotentiallyAliased())
CGF.callCStructCopyAssignmentOperator(DstLV, src);
else
CGF.callCStructCopyConstructor(DstLV, src);
return;
}
}
AggValueSlot srcAgg = AggValueSlot::forLValue(
src, CGF, AggValueSlot::IsDestructed, needsGC(type),
AggValueSlot::IsAliased, AggValueSlot::MayOverlap);
EmitCopy(type, Dest, srcAgg);
}
/// Perform a copy from the source into the destination.
///
/// \param type - the type of the aggregate being copied; qualifiers are
/// ignored
void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest,
const AggValueSlot &src) {
if (dest.requiresGCollection()) {
CharUnits sz = dest.getPreferredSize(CGF.getContext(), type);
llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity());
CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF,
dest.getAddress(),
src.getAddress(),
size);
return;
}
// If the result of the assignment is used, copy the LHS there also.
// It's volatile if either side is. Use the minimum alignment of
// the two sides.
LValue DestLV = CGF.MakeAddrLValue(dest.getAddress(), type);
LValue SrcLV = CGF.MakeAddrLValue(src.getAddress(), type);
CGF.EmitAggregateCopy(DestLV, SrcLV, type, dest.mayOverlap(),
dest.isVolatile() || src.isVolatile());
}
/// Emit the initializer for a std::initializer_list initialized with a
/// real initializer list.
void
AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
// Emit an array containing the elements. The array is externally destructed
// if the std::initializer_list object is.
ASTContext &Ctx = CGF.getContext();
LValue Array = CGF.EmitLValue(E->getSubExpr());
assert(Array.isSimple() && "initializer_list array not a simple lvalue");
Address ArrayPtr = Array.getAddress(CGF);
const ConstantArrayType *ArrayType =
Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
assert(ArrayType && "std::initializer_list constructed from non-array");
// FIXME: Perform the checks on the field types in SemaInit.
RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
RecordDecl::field_iterator Field = Record->field_begin();
if (Field == Record->field_end()) {
CGF.ErrorUnsupported(E, "weird std::initializer_list");
return;
}
// Start pointer.
if (!Field->getType()->isPointerType() ||
!Ctx.hasSameType(Field->getType()->getPointeeType(),
ArrayType->getElementType())) {
CGF.ErrorUnsupported(E, "weird std::initializer_list");
return;
}
AggValueSlot Dest = EnsureSlot(E->getType());
LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0);
llvm::Value *IdxStart[] = { Zero, Zero };
llvm::Value *ArrayStart = Builder.CreateInBoundsGEP(
ArrayPtr.getElementType(), ArrayPtr.getPointer(), IdxStart, "arraystart");
CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start);
++Field;
if (Field == Record->field_end()) {
CGF.ErrorUnsupported(E, "weird std::initializer_list");
return;
}
llvm::Value *Size = Builder.getInt(ArrayType->getSize());
LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
if (Field->getType()->isPointerType() &&
Ctx.hasSameType(Field->getType()->getPointeeType(),
ArrayType->getElementType())) {
// End pointer.
llvm::Value *IdxEnd[] = { Zero, Size };
llvm::Value *ArrayEnd = Builder.CreateInBoundsGEP(
ArrayPtr.getElementType(), ArrayPtr.getPointer(), IdxEnd, "arrayend");
CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength);
} else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) {
// Length.
CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength);
} else {
CGF.ErrorUnsupported(E, "weird std::initializer_list");
return;
}
}
/// Determine if E is a trivial array filler, that is, one that is
/// equivalent to zero-initialization.
static bool isTrivialFiller(Expr *E) {
if (!E)
return true;
if (isa<ImplicitValueInitExpr>(E))
return true;
if (auto *ILE = dyn_cast<InitListExpr>(E)) {
if (ILE->getNumInits())
return false;
return isTrivialFiller(ILE->getArrayFiller());
}
if (auto *Cons = dyn_cast_or_null<CXXConstructExpr>(E))
return Cons->getConstructor()->isDefaultConstructor() &&
Cons->getConstructor()->isTrivial();
// FIXME: Are there other cases where we can avoid emitting an initializer?
return false;
}
/// Emit initialization of an array from an initializer list. ExprToVisit must
/// be either an InitListEpxr a CXXParenInitListExpr.
void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
QualType ArrayQTy, Expr *ExprToVisit,
ArrayRef<Expr *> Args, Expr *ArrayFiller) {
uint64_t NumInitElements = Args.size();
uint64_t NumArrayElements = AType->getNumElements();
assert(NumInitElements <= NumArrayElements);
QualType elementType =
CGF.getContext().getAsArrayType(ArrayQTy)->getElementType();
// DestPtr is an array*. Construct an elementType* by drilling
// down a level.
llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
llvm::Value *indices[] = { zero, zero };
llvm::Value *begin = Builder.CreateInBoundsGEP(
DestPtr.getElementType(), DestPtr.getPointer(), indices,
"arrayinit.begin");
CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
CharUnits elementAlign =
DestPtr.getAlignment().alignmentOfArrayElement(elementSize);
llvm::Type *llvmElementType = CGF.ConvertTypeForMem(elementType);
// Consider initializing the array by copying from a global. For this to be
// more efficient than per-element initialization, the size of the elements
// with explicit initializers should be large enough.
if (NumInitElements * elementSize.getQuantity() > 16 &&
elementType.isTriviallyCopyableType(CGF.getContext())) {
CodeGen::CodeGenModule &CGM = CGF.CGM;
ConstantEmitter Emitter(CGF);
LangAS AS = ArrayQTy.getAddressSpace();
if (llvm::Constant *C =
Emitter.tryEmitForInitializer(ExprToVisit, AS, ArrayQTy)) {
auto GV = new llvm::GlobalVariable(
CGM.getModule(), C->getType(),
/* isConstant= */ true, llvm::GlobalValue::PrivateLinkage, C,
"constinit",
/* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal,
CGM.getContext().getTargetAddressSpace(AS));
Emitter.finalize(GV);
CharUnits Align = CGM.getContext().getTypeAlignInChars(ArrayQTy);
GV->setAlignment(Align.getAsAlign());
Address GVAddr(GV, GV->getValueType(), Align);
EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GVAddr, ArrayQTy));
return;
}
}
// Exception safety requires us to destroy all the
// already-constructed members if an initializer throws.
// For that, we'll need an EH cleanup.
QualType::DestructionKind dtorKind = elementType.isDestructedType();
Address endOfInit = Address::invalid();
EHScopeStack::stable_iterator cleanup;
llvm::Instruction *cleanupDominator = nullptr;
if (CGF.needsEHCleanup(dtorKind)) {
// In principle we could tell the cleanup where we are more
// directly, but the control flow can get so varied here that it
// would actually be quite complex. Therefore we go through an
// alloca.
endOfInit = CGF.CreateTempAlloca(begin->getType(), CGF.getPointerAlign(),
"arrayinit.endOfInit");
cleanupDominator = Builder.CreateStore(begin, endOfInit);
CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType,
elementAlign,
CGF.getDestroyer(dtorKind));
cleanup = CGF.EHStack.stable_begin();
// Otherwise, remember that we didn't need a cleanup.
} else {
dtorKind = QualType::DK_none;
}
llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1);
// The 'current element to initialize'. The invariants on this
// variable are complicated. Essentially, after each iteration of
// the loop, it points to the last initialized element, except
// that it points to the beginning of the array before any
// elements have been initialized.
llvm::Value *element = begin;
// Emit the explicit initializers.
for (uint64_t i = 0; i != NumInitElements; ++i) {
// Advance to the next element.
if (i > 0) {
element = Builder.CreateInBoundsGEP(
llvmElementType, element, one, "arrayinit.element");
// Tell the cleanup that it needs to destroy up to this
// element. TODO: some of these stores can be trivially
// observed to be unnecessary.
if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
}
LValue elementLV = CGF.MakeAddrLValue(
Address(element, llvmElementType, elementAlign), elementType);
EmitInitializationToLValue(Args[i], elementLV);
}
// Check whether there's a non-trivial array-fill expression.
bool hasTrivialFiller = isTrivialFiller(ArrayFiller);
// Any remaining elements need to be zero-initialized, possibly
// using the filler expression. We can skip this if the we're
// emitting to zeroed memory.
if (NumInitElements != NumArrayElements &&
!(Dest.isZeroed() && hasTrivialFiller &&
CGF.getTypes().isZeroInitializable(elementType))) {
// Use an actual loop. This is basically
// do { *array++ = filler; } while (array != end);
// Advance to the start of the rest of the array.
if (NumInitElements) {
element = Builder.CreateInBoundsGEP(
llvmElementType, element, one, "arrayinit.start");
if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
}
// Compute the end of the array.
llvm::Value *end = Builder.CreateInBoundsGEP(
llvmElementType, begin,
llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements), "arrayinit.end");
llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
// Jump into the body.
CGF.EmitBlock(bodyBB);
llvm::PHINode *currentElement =
Builder.CreatePHI(element->getType(), 2, "arrayinit.cur");
currentElement->addIncoming(element, entryBB);
// Emit the actual filler expression.
{
// C++1z [class.temporary]p5:
// when a default constructor is called to initialize an element of
// an array with no corresponding initializer [...] the destruction of
// every temporary created in a default argument is sequenced before
// the construction of the next array element, if any
CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
LValue elementLV = CGF.MakeAddrLValue(
Address(currentElement, llvmElementType, elementAlign), elementType);
if (ArrayFiller)
EmitInitializationToLValue(ArrayFiller, elementLV);
else
EmitNullInitializationToLValue(elementLV);
}
// Move on to the next element.
llvm::Value *nextElement = Builder.CreateInBoundsGEP(
llvmElementType, currentElement, one, "arrayinit.next");
// Tell the EH cleanup that we finished with the last element.
if (endOfInit.isValid()) Builder.CreateStore(nextElement, endOfInit);
// Leave the loop if we're done.
llvm::Value *done = Builder.CreateICmpEQ(nextElement, end,
"arrayinit.done");
llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
Builder.CreateCondBr(done, endBB, bodyBB);
currentElement->addIncoming(nextElement, Builder.GetInsertBlock());
CGF.EmitBlock(endBB);
}
// Leave the partial-array cleanup if we entered one.
if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator);
}
//===----------------------------------------------------------------------===//
// Visitor Methods
//===----------------------------------------------------------------------===//
void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){
Visit(E->getSubExpr());
}
void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) {
// If this is a unique OVE, just visit its source expression.
if (e->isUnique())
Visit(e->getSourceExpr());
else
EmitFinalDestCopy(e->getType(), CGF.getOrCreateOpaqueLValueMapping(e));
}
void
AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
if (Dest.isPotentiallyAliased() &&
E->getType().isPODType(CGF.getContext())) {
// For a POD type, just emit a load of the lvalue + a copy, because our
// compound literal might alias the destination.
EmitAggLoadOfLValue(E);
return;
}
AggValueSlot Slot = EnsureSlot(E->getType());
// Block-scope compound literals are destroyed at the end of the enclosing
// scope in C.
bool Destruct =
!CGF.getLangOpts().CPlusPlus && !Slot.isExternallyDestructed();
if (Destruct)
Slot.setExternallyDestructed();
CGF.EmitAggExpr(E->getInitializer(), Slot);
if (Destruct)
if (QualType::DestructionKind DtorKind = E->getType().isDestructedType())
CGF.pushLifetimeExtendedDestroy(
CGF.getCleanupKind(DtorKind), Slot.getAddress(), E->getType(),
CGF.getDestroyer(DtorKind), DtorKind & EHCleanup);
}
/// Attempt to look through various unimportant expressions to find a
/// cast of the given kind.
static Expr *findPeephole(Expr *op, CastKind kind, const ASTContext &ctx) {
op = op->IgnoreParenNoopCasts(ctx);
if (auto castE = dyn_cast<CastExpr>(op)) {
if (castE->getCastKind() == kind)
return castE->getSubExpr();
}
return nullptr;
}
void AggExprEmitter::VisitCastExpr(CastExpr *E) {
if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
switch (E->getCastKind()) {
case CK_Dynamic: {
// FIXME: Can this actually happen? We have no test coverage for it.
assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?");
LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(),
CodeGenFunction::TCK_Load);
// FIXME: Do we also need to handle property references here?
if (LV.isSimple())
CGF.EmitDynamicCast(LV.getAddress(CGF), cast<CXXDynamicCastExpr>(E));
else
CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast");
if (!Dest.isIgnored())
CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination");
break;
}
case CK_ToUnion: {
// Evaluate even if the destination is ignored.
if (Dest.isIgnored()) {
CGF.EmitAnyExpr(E->getSubExpr(), AggValueSlot::ignored(),
/*ignoreResult=*/true);
break;
}
// GCC union extension
QualType Ty = E->getSubExpr()->getType();
Address CastPtr = Dest.getAddress().withElementType(CGF.ConvertType(Ty));
EmitInitializationToLValue(E->getSubExpr(),
CGF.MakeAddrLValue(CastPtr, Ty));
break;
}
case CK_LValueToRValueBitCast: {
if (Dest.isIgnored()) {
CGF.EmitAnyExpr(E->getSubExpr(), AggValueSlot::ignored(),
/*ignoreResult=*/true);
break;
}
LValue SourceLV = CGF.EmitLValue(E->getSubExpr());
Address SourceAddress =
SourceLV.getAddress(CGF).withElementType(CGF.Int8Ty);
Address DestAddress = Dest.getAddress().withElementType(CGF.Int8Ty);
llvm::Value *SizeVal = llvm::ConstantInt::get(
CGF.SizeTy,
CGF.getContext().getTypeSizeInChars(E->getType()).getQuantity());
Builder.CreateMemCpy(DestAddress, SourceAddress, SizeVal);
break;
}
case CK_DerivedToBase:
case CK_BaseToDerived:
case CK_UncheckedDerivedToBase: {
llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: "
"should have been unpacked before we got here");
}
case CK_NonAtomicToAtomic:
case CK_AtomicToNonAtomic: {
bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic);
// Determine the atomic and value types.
QualType atomicType = E->getSubExpr()->getType();
QualType valueType = E->getType();
if (isToAtomic) std::swap(atomicType, valueType);
assert(atomicType->isAtomicType());
assert(CGF.getContext().hasSameUnqualifiedType(valueType,
atomicType->castAs<AtomicType>()->getValueType()));
// Just recurse normally if we're ignoring the result or the
// atomic type doesn't change representation.
if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) {
return Visit(E->getSubExpr());
}
CastKind peepholeTarget =
(isToAtomic ? CK_AtomicToNonAtomic : CK_NonAtomicToAtomic);
// These two cases are reverses of each other; try to peephole them.
if (Expr *op =
findPeephole(E->getSubExpr(), peepholeTarget, CGF.getContext())) {
assert(CGF.getContext().hasSameUnqualifiedType(op->getType(),
E->getType()) &&
"peephole significantly changed types?");
return Visit(op);
}
// If we're converting an r-value of non-atomic type to an r-value
// of atomic type, just emit directly into the relevant sub-object.
if (isToAtomic) {
AggValueSlot valueDest = Dest;
if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) {
// Zero-initialize. (Strictly speaking, we only need to initialize
// the padding at the end, but this is simpler.)
if (!Dest.isZeroed())
CGF.EmitNullInitialization(Dest.getAddress(), atomicType);
// Build a GEP to refer to the subobject.
Address valueAddr =
CGF.Builder.CreateStructGEP(valueDest.getAddress(), 0);
valueDest = AggValueSlot::forAddr(valueAddr,
valueDest.getQualifiers(),
valueDest.isExternallyDestructed(),
valueDest.requiresGCollection(),
valueDest.isPotentiallyAliased(),
AggValueSlot::DoesNotOverlap,
AggValueSlot::IsZeroed);
}
CGF.EmitAggExpr(E->getSubExpr(), valueDest);
return;
}
// Otherwise, we're converting an atomic type to a non-atomic type.
// Make an atomic temporary, emit into that, and then copy the value out.
AggValueSlot atomicSlot =
CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp");
CGF.EmitAggExpr(E->getSubExpr(), atomicSlot);
Address valueAddr = Builder.CreateStructGEP(atomicSlot.getAddress(), 0);
RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile());
return EmitFinalDestCopy(valueType, rvalue);
}
case CK_AddressSpaceConversion:
return Visit(E->getSubExpr());
case CK_LValueToRValue:
// If we're loading from a volatile type, force the destination
// into existence.
if (E->getSubExpr()->getType().isVolatileQualified()) {
bool Destruct =
!Dest.isExternallyDestructed() &&
E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct;
if (Destruct)
Dest.setExternallyDestructed();
EnsureDest(E->getType());
Visit(E->getSubExpr());
if (Destruct)
CGF.pushDestroy(QualType::DK_nontrivial_c_struct, Dest.getAddress(),
E->getType());
return;
}
[[fallthrough]];
case CK_NoOp:
case CK_UserDefinedConversion:
case CK_ConstructorConversion:
assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
E->getType()) &&
"Implicit cast types must be compatible");
Visit(E->getSubExpr());
break;
case CK_LValueBitCast:
llvm_unreachable("should not be emitting lvalue bitcast as rvalue");
case CK_Dependent:
case CK_BitCast:
case CK_ArrayToPointerDecay:
case CK_FunctionToPointerDecay:
case CK_NullToPointer:
case CK_NullToMemberPointer:
case CK_BaseToDerivedMemberPointer:
case CK_DerivedToBaseMemberPointer:
case CK_MemberPointerToBoolean:
case CK_ReinterpretMemberPointer:
case CK_IntegralToPointer:
case CK_PointerToIntegral:
case CK_PointerToBoolean:
case CK_ToVoid:
case CK_VectorSplat:
case CK_IntegralCast:
case CK_BooleanToSignedIntegral:
case CK_IntegralToBoolean:
case CK_IntegralToFloating:
case CK_FloatingToIntegral:
case CK_FloatingToBoolean:
case CK_FloatingCast:
case CK_CPointerToObjCPointerCast:
case CK_BlockPointerToObjCPointerCast:
case CK_AnyPointerToBlockPointerCast:
case CK_ObjCObjectLValueCast:
case CK_FloatingRealToComplex:
case CK_FloatingComplexToReal:
case CK_FloatingComplexToBoolean:
case CK_FloatingComplexCast:
case CK_FloatingComplexToIntegralComplex:
case CK_IntegralRealToComplex:
case CK_IntegralComplexToReal:
case CK_IntegralComplexToBoolean:
case CK_IntegralComplexCast:
case CK_IntegralComplexToFloatingComplex:
case CK_ARCProduceObject:
case CK_ARCConsumeObject:
case CK_ARCReclaimReturnedObject:
case CK_ARCExtendBlockObject:
case CK_CopyAndAutoreleaseBlockObject:
case CK_BuiltinFnToFnPtr:
case CK_ZeroToOCLOpaqueType:
case CK_MatrixCast:
case CK_HLSLVectorTruncation:
case CK_IntToOCLSampler:
case CK_FloatingToFixedPoint:
case CK_FixedPointToFloating:
case CK_FixedPointCast:
case CK_FixedPointToBoolean:
case CK_FixedPointToIntegral:
case CK_IntegralToFixedPoint:
llvm_unreachable("cast kind invalid for aggregate types");
}
}
void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
if (E->getCallReturnType(CGF.getContext())->isReferenceType()) {
EmitAggLoadOfLValue(E);
return;
}
withReturnValueSlot(E, [&](ReturnValueSlot Slot) {
return CGF.EmitCallExpr(E, Slot);
});
}
void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
withReturnValueSlot(E, [&](ReturnValueSlot Slot) {
return CGF.EmitObjCMessageExpr(E, Slot);
});
}
void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
CGF.EmitIgnoredExpr(E->getLHS());
Visit(E->getRHS());
}
void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
CodeGenFunction::StmtExprEvaluation eval(CGF);
CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest);
}
enum CompareKind {
CK_Less,
CK_Greater,
CK_Equal,
};
static llvm::Value *EmitCompare(CGBuilderTy &Builder, CodeGenFunction &CGF,
const BinaryOperator *E, llvm::Value *LHS,
llvm::Value *RHS, CompareKind Kind,
const char *NameSuffix = "") {
QualType ArgTy = E->getLHS()->getType();
if (const ComplexType *CT = ArgTy->getAs<ComplexType>())
ArgTy = CT->getElementType();
if (const auto *MPT = ArgTy->getAs<MemberPointerType>()) {
assert(Kind == CK_Equal &&
"member pointers may only be compared for equality");
return CGF.CGM.getCXXABI().EmitMemberPointerComparison(
CGF, LHS, RHS, MPT, /*IsInequality*/ false);
}