forked from llvm/llvm-project
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathBTFDebug.cpp
1512 lines (1315 loc) · 48.1 KB
/
BTFDebug.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
//===- BTFDebug.cpp - BTF Generator ---------------------------------------===//
//
// 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 file contains support for writing BTF debug info.
//
//===----------------------------------------------------------------------===//
#include "BTFDebug.h"
#include "BPF.h"
#include "BPFCORE.h"
#include "MCTargetDesc/BPFMCTargetDesc.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/LineIterator.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
using namespace llvm;
static const char *BTFKindStr[] = {
#define HANDLE_BTF_KIND(ID, NAME) "BTF_KIND_" #NAME,
#include "BTF.def"
};
/// Emit a BTF common type.
void BTFTypeBase::emitType(MCStreamer &OS) {
OS.AddComment(std::string(BTFKindStr[Kind]) + "(id = " + std::to_string(Id) +
")");
OS.emitInt32(BTFType.NameOff);
OS.AddComment("0x" + Twine::utohexstr(BTFType.Info));
OS.emitInt32(BTFType.Info);
OS.emitInt32(BTFType.Size);
}
BTFTypeDerived::BTFTypeDerived(const DIDerivedType *DTy, unsigned Tag,
bool NeedsFixup)
: DTy(DTy), NeedsFixup(NeedsFixup), Name(DTy->getName()) {
switch (Tag) {
case dwarf::DW_TAG_pointer_type:
Kind = BTF::BTF_KIND_PTR;
break;
case dwarf::DW_TAG_const_type:
Kind = BTF::BTF_KIND_CONST;
break;
case dwarf::DW_TAG_volatile_type:
Kind = BTF::BTF_KIND_VOLATILE;
break;
case dwarf::DW_TAG_typedef:
Kind = BTF::BTF_KIND_TYPEDEF;
break;
case dwarf::DW_TAG_restrict_type:
Kind = BTF::BTF_KIND_RESTRICT;
break;
default:
llvm_unreachable("Unknown DIDerivedType Tag");
}
BTFType.Info = Kind << 24;
}
/// Used by DW_TAG_pointer_type only.
BTFTypeDerived::BTFTypeDerived(unsigned NextTypeId, unsigned Tag,
StringRef Name)
: DTy(nullptr), NeedsFixup(false), Name(Name) {
Kind = BTF::BTF_KIND_PTR;
BTFType.Info = Kind << 24;
BTFType.Type = NextTypeId;
}
void BTFTypeDerived::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(Name);
if (NeedsFixup || !DTy)
return;
// The base type for PTR/CONST/VOLATILE could be void.
const DIType *ResolvedType = DTy->getBaseType();
if (!ResolvedType) {
assert((Kind == BTF::BTF_KIND_PTR || Kind == BTF::BTF_KIND_CONST ||
Kind == BTF::BTF_KIND_VOLATILE) &&
"Invalid null basetype");
BTFType.Type = 0;
} else {
BTFType.Type = BDebug.getTypeId(ResolvedType);
}
}
void BTFTypeDerived::emitType(MCStreamer &OS) { BTFTypeBase::emitType(OS); }
void BTFTypeDerived::setPointeeType(uint32_t PointeeType) {
BTFType.Type = PointeeType;
}
/// Represent a struct/union forward declaration.
BTFTypeFwd::BTFTypeFwd(StringRef Name, bool IsUnion) : Name(Name) {
Kind = BTF::BTF_KIND_FWD;
BTFType.Info = IsUnion << 31 | Kind << 24;
BTFType.Type = 0;
}
void BTFTypeFwd::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(Name);
}
void BTFTypeFwd::emitType(MCStreamer &OS) { BTFTypeBase::emitType(OS); }
BTFTypeInt::BTFTypeInt(uint32_t Encoding, uint32_t SizeInBits,
uint32_t OffsetInBits, StringRef TypeName)
: Name(TypeName) {
// Translate IR int encoding to BTF int encoding.
uint8_t BTFEncoding;
switch (Encoding) {
case dwarf::DW_ATE_boolean:
BTFEncoding = BTF::INT_BOOL;
break;
case dwarf::DW_ATE_signed:
case dwarf::DW_ATE_signed_char:
BTFEncoding = BTF::INT_SIGNED;
break;
case dwarf::DW_ATE_unsigned:
case dwarf::DW_ATE_unsigned_char:
BTFEncoding = 0;
break;
default:
llvm_unreachable("Unknown BTFTypeInt Encoding");
}
Kind = BTF::BTF_KIND_INT;
BTFType.Info = Kind << 24;
BTFType.Size = roundupToBytes(SizeInBits);
IntVal = (BTFEncoding << 24) | OffsetInBits << 16 | SizeInBits;
}
void BTFTypeInt::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(Name);
}
void BTFTypeInt::emitType(MCStreamer &OS) {
BTFTypeBase::emitType(OS);
OS.AddComment("0x" + Twine::utohexstr(IntVal));
OS.emitInt32(IntVal);
}
BTFTypeEnum::BTFTypeEnum(const DICompositeType *ETy, uint32_t VLen) : ETy(ETy) {
Kind = BTF::BTF_KIND_ENUM;
BTFType.Info = Kind << 24 | VLen;
BTFType.Size = roundupToBytes(ETy->getSizeInBits());
}
void BTFTypeEnum::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(ETy->getName());
DINodeArray Elements = ETy->getElements();
for (const auto Element : Elements) {
const auto *Enum = cast<DIEnumerator>(Element);
struct BTF::BTFEnum BTFEnum;
BTFEnum.NameOff = BDebug.addString(Enum->getName());
// BTF enum value is 32bit, enforce it.
uint32_t Value;
if (Enum->isUnsigned())
Value = static_cast<uint32_t>(Enum->getValue().getZExtValue());
else
Value = static_cast<uint32_t>(Enum->getValue().getSExtValue());
BTFEnum.Val = Value;
EnumValues.push_back(BTFEnum);
}
}
void BTFTypeEnum::emitType(MCStreamer &OS) {
BTFTypeBase::emitType(OS);
for (const auto &Enum : EnumValues) {
OS.emitInt32(Enum.NameOff);
OS.emitInt32(Enum.Val);
}
}
BTFTypeArray::BTFTypeArray(uint32_t ElemTypeId, uint32_t NumElems) {
Kind = BTF::BTF_KIND_ARRAY;
BTFType.NameOff = 0;
BTFType.Info = Kind << 24;
BTFType.Size = 0;
ArrayInfo.ElemType = ElemTypeId;
ArrayInfo.Nelems = NumElems;
}
/// Represent a BTF array.
void BTFTypeArray::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
// The IR does not really have a type for the index.
// A special type for array index should have been
// created during initial type traversal. Just
// retrieve that type id.
ArrayInfo.IndexType = BDebug.getArrayIndexTypeId();
}
void BTFTypeArray::emitType(MCStreamer &OS) {
BTFTypeBase::emitType(OS);
OS.emitInt32(ArrayInfo.ElemType);
OS.emitInt32(ArrayInfo.IndexType);
OS.emitInt32(ArrayInfo.Nelems);
}
/// Represent either a struct or a union.
BTFTypeStruct::BTFTypeStruct(const DICompositeType *STy, bool IsStruct,
bool HasBitField, uint32_t Vlen)
: STy(STy), HasBitField(HasBitField) {
Kind = IsStruct ? BTF::BTF_KIND_STRUCT : BTF::BTF_KIND_UNION;
BTFType.Size = roundupToBytes(STy->getSizeInBits());
BTFType.Info = (HasBitField << 31) | (Kind << 24) | Vlen;
}
void BTFTypeStruct::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(STy->getName());
// Add struct/union members.
const DINodeArray Elements = STy->getElements();
for (const auto *Element : Elements) {
struct BTF::BTFMember BTFMember;
const auto *DDTy = cast<DIDerivedType>(Element);
BTFMember.NameOff = BDebug.addString(DDTy->getName());
if (HasBitField) {
uint8_t BitFieldSize = DDTy->isBitField() ? DDTy->getSizeInBits() : 0;
BTFMember.Offset = BitFieldSize << 24 | DDTy->getOffsetInBits();
} else {
BTFMember.Offset = DDTy->getOffsetInBits();
}
const auto *BaseTy = DDTy->getBaseType();
BTFMember.Type = BDebug.getTypeId(BaseTy);
Members.push_back(BTFMember);
}
}
void BTFTypeStruct::emitType(MCStreamer &OS) {
BTFTypeBase::emitType(OS);
for (const auto &Member : Members) {
OS.emitInt32(Member.NameOff);
OS.emitInt32(Member.Type);
OS.AddComment("0x" + Twine::utohexstr(Member.Offset));
OS.emitInt32(Member.Offset);
}
}
std::string BTFTypeStruct::getName() { return std::string(STy->getName()); }
/// The Func kind represents both subprogram and pointee of function
/// pointers. If the FuncName is empty, it represents a pointee of function
/// pointer. Otherwise, it represents a subprogram. The func arg names
/// are empty for pointee of function pointer case, and are valid names
/// for subprogram.
BTFTypeFuncProto::BTFTypeFuncProto(
const DISubroutineType *STy, uint32_t VLen,
const std::unordered_map<uint32_t, StringRef> &FuncArgNames)
: STy(STy), FuncArgNames(FuncArgNames) {
Kind = BTF::BTF_KIND_FUNC_PROTO;
BTFType.Info = (Kind << 24) | VLen;
}
void BTFTypeFuncProto::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
DITypeRefArray Elements = STy->getTypeArray();
auto RetType = Elements[0];
BTFType.Type = RetType ? BDebug.getTypeId(RetType) : 0;
BTFType.NameOff = 0;
// For null parameter which is typically the last one
// to represent the vararg, encode the NameOff/Type to be 0.
for (unsigned I = 1, N = Elements.size(); I < N; ++I) {
struct BTF::BTFParam Param;
auto Element = Elements[I];
if (Element) {
Param.NameOff = BDebug.addString(FuncArgNames[I]);
Param.Type = BDebug.getTypeId(Element);
} else {
Param.NameOff = 0;
Param.Type = 0;
}
Parameters.push_back(Param);
}
}
void BTFTypeFuncProto::emitType(MCStreamer &OS) {
BTFTypeBase::emitType(OS);
for (const auto &Param : Parameters) {
OS.emitInt32(Param.NameOff);
OS.emitInt32(Param.Type);
}
}
BTFTypeFunc::BTFTypeFunc(StringRef FuncName, uint32_t ProtoTypeId,
uint32_t Scope)
: Name(FuncName) {
Kind = BTF::BTF_KIND_FUNC;
BTFType.Info = (Kind << 24) | Scope;
BTFType.Type = ProtoTypeId;
}
void BTFTypeFunc::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(Name);
}
void BTFTypeFunc::emitType(MCStreamer &OS) { BTFTypeBase::emitType(OS); }
BTFKindVar::BTFKindVar(StringRef VarName, uint32_t TypeId, uint32_t VarInfo)
: Name(VarName) {
Kind = BTF::BTF_KIND_VAR;
BTFType.Info = Kind << 24;
BTFType.Type = TypeId;
Info = VarInfo;
}
void BTFKindVar::completeType(BTFDebug &BDebug) {
BTFType.NameOff = BDebug.addString(Name);
}
void BTFKindVar::emitType(MCStreamer &OS) {
BTFTypeBase::emitType(OS);
OS.emitInt32(Info);
}
BTFKindDataSec::BTFKindDataSec(AsmPrinter *AsmPrt, std::string SecName)
: Asm(AsmPrt), Name(SecName) {
Kind = BTF::BTF_KIND_DATASEC;
BTFType.Info = Kind << 24;
BTFType.Size = 0;
}
void BTFKindDataSec::completeType(BTFDebug &BDebug) {
BTFType.NameOff = BDebug.addString(Name);
BTFType.Info |= Vars.size();
}
void BTFKindDataSec::emitType(MCStreamer &OS) {
BTFTypeBase::emitType(OS);
for (const auto &V : Vars) {
OS.emitInt32(std::get<0>(V));
Asm->emitLabelReference(std::get<1>(V), 4);
OS.emitInt32(std::get<2>(V));
}
}
BTFTypeFloat::BTFTypeFloat(uint32_t SizeInBits, StringRef TypeName)
: Name(TypeName) {
Kind = BTF::BTF_KIND_FLOAT;
BTFType.Info = Kind << 24;
BTFType.Size = roundupToBytes(SizeInBits);
}
void BTFTypeFloat::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(Name);
}
BTFTypeDeclTag::BTFTypeDeclTag(uint32_t BaseTypeId, int ComponentIdx,
StringRef Tag)
: Tag(Tag) {
Kind = BTF::BTF_KIND_DECL_TAG;
BTFType.Info = Kind << 24;
BTFType.Type = BaseTypeId;
Info = ComponentIdx;
}
void BTFTypeDeclTag::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(Tag);
}
void BTFTypeDeclTag::emitType(MCStreamer &OS) {
BTFTypeBase::emitType(OS);
OS.emitInt32(Info);
}
BTFTypeTypeTag::BTFTypeTypeTag(uint32_t NextTypeId, StringRef Tag)
: DTy(nullptr), Tag(Tag) {
Kind = BTF::BTF_KIND_TYPE_TAG;
BTFType.Info = Kind << 24;
BTFType.Type = NextTypeId;
}
BTFTypeTypeTag::BTFTypeTypeTag(const DIDerivedType *DTy, StringRef Tag)
: DTy(DTy), Tag(Tag) {
Kind = BTF::BTF_KIND_TYPE_TAG;
BTFType.Info = Kind << 24;
}
void BTFTypeTypeTag::completeType(BTFDebug &BDebug) {
if (IsCompleted)
return;
IsCompleted = true;
BTFType.NameOff = BDebug.addString(Tag);
if (DTy) {
const DIType *ResolvedType = DTy->getBaseType();
if (!ResolvedType)
BTFType.Type = 0;
else
BTFType.Type = BDebug.getTypeId(ResolvedType);
}
}
uint32_t BTFStringTable::addString(StringRef S) {
// Check whether the string already exists.
for (auto &OffsetM : OffsetToIdMap) {
if (Table[OffsetM.second] == S)
return OffsetM.first;
}
// Not find, add to the string table.
uint32_t Offset = Size;
OffsetToIdMap[Offset] = Table.size();
Table.push_back(std::string(S));
Size += S.size() + 1;
return Offset;
}
BTFDebug::BTFDebug(AsmPrinter *AP)
: DebugHandlerBase(AP), OS(*Asm->OutStreamer), SkipInstruction(false),
LineInfoGenerated(false), SecNameOff(0), ArrayIndexTypeId(0),
MapDefNotCollected(true) {
addString("\0");
}
uint32_t BTFDebug::addType(std::unique_ptr<BTFTypeBase> TypeEntry,
const DIType *Ty) {
TypeEntry->setId(TypeEntries.size() + 1);
uint32_t Id = TypeEntry->getId();
DIToIdMap[Ty] = Id;
TypeEntries.push_back(std::move(TypeEntry));
return Id;
}
uint32_t BTFDebug::addType(std::unique_ptr<BTFTypeBase> TypeEntry) {
TypeEntry->setId(TypeEntries.size() + 1);
uint32_t Id = TypeEntry->getId();
TypeEntries.push_back(std::move(TypeEntry));
return Id;
}
void BTFDebug::visitBasicType(const DIBasicType *BTy, uint32_t &TypeId) {
// Only int and binary floating point types are supported in BTF.
uint32_t Encoding = BTy->getEncoding();
std::unique_ptr<BTFTypeBase> TypeEntry;
switch (Encoding) {
case dwarf::DW_ATE_boolean:
case dwarf::DW_ATE_signed:
case dwarf::DW_ATE_signed_char:
case dwarf::DW_ATE_unsigned:
case dwarf::DW_ATE_unsigned_char:
// Create a BTF type instance for this DIBasicType and put it into
// DIToIdMap for cross-type reference check.
TypeEntry = std::make_unique<BTFTypeInt>(
Encoding, BTy->getSizeInBits(), BTy->getOffsetInBits(), BTy->getName());
break;
case dwarf::DW_ATE_float:
TypeEntry =
std::make_unique<BTFTypeFloat>(BTy->getSizeInBits(), BTy->getName());
break;
default:
return;
}
TypeId = addType(std::move(TypeEntry), BTy);
}
/// Handle subprogram or subroutine types.
void BTFDebug::visitSubroutineType(
const DISubroutineType *STy, bool ForSubprog,
const std::unordered_map<uint32_t, StringRef> &FuncArgNames,
uint32_t &TypeId) {
DITypeRefArray Elements = STy->getTypeArray();
uint32_t VLen = Elements.size() - 1;
if (VLen > BTF::MAX_VLEN)
return;
// Subprogram has a valid non-zero-length name, and the pointee of
// a function pointer has an empty name. The subprogram type will
// not be added to DIToIdMap as it should not be referenced by
// any other types.
auto TypeEntry = std::make_unique<BTFTypeFuncProto>(STy, VLen, FuncArgNames);
if (ForSubprog)
TypeId = addType(std::move(TypeEntry)); // For subprogram
else
TypeId = addType(std::move(TypeEntry), STy); // For func ptr
// Visit return type and func arg types.
for (const auto Element : Elements) {
visitTypeEntry(Element);
}
}
void BTFDebug::processDeclAnnotations(DINodeArray Annotations,
uint32_t BaseTypeId,
int ComponentIdx) {
if (!Annotations)
return;
for (const Metadata *Annotation : Annotations->operands()) {
const MDNode *MD = cast<MDNode>(Annotation);
const MDString *Name = cast<MDString>(MD->getOperand(0));
if (!Name->getString().equals("btf_decl_tag"))
continue;
const MDString *Value = cast<MDString>(MD->getOperand(1));
auto TypeEntry = std::make_unique<BTFTypeDeclTag>(BaseTypeId, ComponentIdx,
Value->getString());
addType(std::move(TypeEntry));
}
}
/// Handle structure/union types.
void BTFDebug::visitStructType(const DICompositeType *CTy, bool IsStruct,
uint32_t &TypeId) {
const DINodeArray Elements = CTy->getElements();
uint32_t VLen = Elements.size();
if (VLen > BTF::MAX_VLEN)
return;
// Check whether we have any bitfield members or not
bool HasBitField = false;
for (const auto *Element : Elements) {
auto E = cast<DIDerivedType>(Element);
if (E->isBitField()) {
HasBitField = true;
break;
}
}
auto TypeEntry =
std::make_unique<BTFTypeStruct>(CTy, IsStruct, HasBitField, VLen);
StructTypes.push_back(TypeEntry.get());
TypeId = addType(std::move(TypeEntry), CTy);
// Check struct/union annotations
processDeclAnnotations(CTy->getAnnotations(), TypeId, -1);
// Visit all struct members.
int FieldNo = 0;
for (const auto *Element : Elements) {
const auto Elem = cast<DIDerivedType>(Element);
visitTypeEntry(Elem);
processDeclAnnotations(Elem->getAnnotations(), TypeId, FieldNo);
FieldNo++;
}
}
void BTFDebug::visitArrayType(const DICompositeType *CTy, uint32_t &TypeId) {
// Visit array element type.
uint32_t ElemTypeId;
const DIType *ElemType = CTy->getBaseType();
visitTypeEntry(ElemType, ElemTypeId, false, false);
// Visit array dimensions.
DINodeArray Elements = CTy->getElements();
for (int I = Elements.size() - 1; I >= 0; --I) {
if (auto *Element = dyn_cast_or_null<DINode>(Elements[I]))
if (Element->getTag() == dwarf::DW_TAG_subrange_type) {
const DISubrange *SR = cast<DISubrange>(Element);
auto *CI = SR->getCount().dyn_cast<ConstantInt *>();
int64_t Count = CI->getSExtValue();
// For struct s { int b; char c[]; }, the c[] will be represented
// as an array with Count = -1.
auto TypeEntry =
std::make_unique<BTFTypeArray>(ElemTypeId,
Count >= 0 ? Count : 0);
if (I == 0)
ElemTypeId = addType(std::move(TypeEntry), CTy);
else
ElemTypeId = addType(std::move(TypeEntry));
}
}
// The array TypeId is the type id of the outermost dimension.
TypeId = ElemTypeId;
// The IR does not have a type for array index while BTF wants one.
// So create an array index type if there is none.
if (!ArrayIndexTypeId) {
auto TypeEntry = std::make_unique<BTFTypeInt>(dwarf::DW_ATE_unsigned, 32,
0, "__ARRAY_SIZE_TYPE__");
ArrayIndexTypeId = addType(std::move(TypeEntry));
}
}
void BTFDebug::visitEnumType(const DICompositeType *CTy, uint32_t &TypeId) {
DINodeArray Elements = CTy->getElements();
uint32_t VLen = Elements.size();
if (VLen > BTF::MAX_VLEN)
return;
auto TypeEntry = std::make_unique<BTFTypeEnum>(CTy, VLen);
TypeId = addType(std::move(TypeEntry), CTy);
// No need to visit base type as BTF does not encode it.
}
/// Handle structure/union forward declarations.
void BTFDebug::visitFwdDeclType(const DICompositeType *CTy, bool IsUnion,
uint32_t &TypeId) {
auto TypeEntry = std::make_unique<BTFTypeFwd>(CTy->getName(), IsUnion);
TypeId = addType(std::move(TypeEntry), CTy);
}
/// Handle structure, union, array and enumeration types.
void BTFDebug::visitCompositeType(const DICompositeType *CTy,
uint32_t &TypeId) {
auto Tag = CTy->getTag();
if (Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type) {
// Handle forward declaration differently as it does not have members.
if (CTy->isForwardDecl())
visitFwdDeclType(CTy, Tag == dwarf::DW_TAG_union_type, TypeId);
else
visitStructType(CTy, Tag == dwarf::DW_TAG_structure_type, TypeId);
} else if (Tag == dwarf::DW_TAG_array_type)
visitArrayType(CTy, TypeId);
else if (Tag == dwarf::DW_TAG_enumeration_type)
visitEnumType(CTy, TypeId);
}
/// Handle pointer, typedef, const, volatile, restrict and member types.
void BTFDebug::visitDerivedType(const DIDerivedType *DTy, uint32_t &TypeId,
bool CheckPointer, bool SeenPointer) {
unsigned Tag = DTy->getTag();
/// Try to avoid chasing pointees, esp. structure pointees which may
/// unnecessary bring in a lot of types.
if (CheckPointer && !SeenPointer) {
SeenPointer = Tag == dwarf::DW_TAG_pointer_type;
}
if (CheckPointer && SeenPointer) {
const DIType *Base = DTy->getBaseType();
if (Base) {
if (const auto *CTy = dyn_cast<DICompositeType>(Base)) {
auto CTag = CTy->getTag();
if ((CTag == dwarf::DW_TAG_structure_type ||
CTag == dwarf::DW_TAG_union_type) &&
!CTy->getName().empty() && !CTy->isForwardDecl()) {
/// Find a candidate, generate a fixup. Later on the struct/union
/// pointee type will be replaced with either a real type or
/// a forward declaration.
auto TypeEntry = std::make_unique<BTFTypeDerived>(DTy, Tag, true);
auto &Fixup = FixupDerivedTypes[CTy->getName()];
Fixup.first = CTag == dwarf::DW_TAG_union_type;
Fixup.second.push_back(TypeEntry.get());
TypeId = addType(std::move(TypeEntry), DTy);
return;
}
}
}
}
if (Tag == dwarf::DW_TAG_pointer_type) {
SmallVector<const MDString *, 4> MDStrs;
DINodeArray Annots = DTy->getAnnotations();
if (Annots) {
// For type with "int __tag1 __tag2 *p", the MDStrs will have
// content: [__tag1, __tag2].
for (const Metadata *Annotations : Annots->operands()) {
const MDNode *MD = cast<MDNode>(Annotations);
const MDString *Name = cast<MDString>(MD->getOperand(0));
if (!Name->getString().equals("btf_type_tag"))
continue;
MDStrs.push_back(cast<MDString>(MD->getOperand(1)));
}
}
if (MDStrs.size() > 0) {
// With MDStrs [__tag1, __tag2], the output type chain looks like
// PTR -> __tag2 -> __tag1 -> BaseType
// In the below, we construct BTF types with the order of __tag1, __tag2
// and PTR.
auto TypeEntry =
std::make_unique<BTFTypeTypeTag>(DTy, MDStrs[0]->getString());
unsigned TmpTypeId = addType(std::move(TypeEntry));
for (unsigned I = 1; I < MDStrs.size(); I++) {
const MDString *Value = MDStrs[I];
TypeEntry =
std::make_unique<BTFTypeTypeTag>(TmpTypeId, Value->getString());
TmpTypeId = addType(std::move(TypeEntry));
}
auto TypeDEntry =
std::make_unique<BTFTypeDerived>(TmpTypeId, Tag, DTy->getName());
TypeId = addType(std::move(TypeDEntry), DTy);
} else {
auto TypeEntry = std::make_unique<BTFTypeDerived>(DTy, Tag, false);
TypeId = addType(std::move(TypeEntry), DTy);
}
} else if (Tag == dwarf::DW_TAG_typedef || Tag == dwarf::DW_TAG_const_type ||
Tag == dwarf::DW_TAG_volatile_type ||
Tag == dwarf::DW_TAG_restrict_type) {
auto TypeEntry = std::make_unique<BTFTypeDerived>(DTy, Tag, false);
TypeId = addType(std::move(TypeEntry), DTy);
if (Tag == dwarf::DW_TAG_typedef)
processDeclAnnotations(DTy->getAnnotations(), TypeId, -1);
} else if (Tag != dwarf::DW_TAG_member) {
return;
}
// Visit base type of pointer, typedef, const, volatile, restrict or
// struct/union member.
uint32_t TempTypeId = 0;
if (Tag == dwarf::DW_TAG_member)
visitTypeEntry(DTy->getBaseType(), TempTypeId, true, false);
else
visitTypeEntry(DTy->getBaseType(), TempTypeId, CheckPointer, SeenPointer);
}
void BTFDebug::visitTypeEntry(const DIType *Ty, uint32_t &TypeId,
bool CheckPointer, bool SeenPointer) {
if (!Ty || DIToIdMap.find(Ty) != DIToIdMap.end()) {
TypeId = DIToIdMap[Ty];
// To handle the case like the following:
// struct t;
// typedef struct t _t;
// struct s1 { _t *c; };
// int test1(struct s1 *arg) { ... }
//
// struct t { int a; int b; };
// struct s2 { _t c; }
// int test2(struct s2 *arg) { ... }
//
// During traversing test1() argument, "_t" is recorded
// in DIToIdMap and a forward declaration fixup is created
// for "struct t" to avoid pointee type traversal.
//
// During traversing test2() argument, even if we see "_t" is
// already defined, we should keep moving to eventually
// bring in types for "struct t". Otherwise, the "struct s2"
// definition won't be correct.
if (Ty && (!CheckPointer || !SeenPointer)) {
if (const auto *DTy = dyn_cast<DIDerivedType>(Ty)) {
unsigned Tag = DTy->getTag();
if (Tag == dwarf::DW_TAG_typedef || Tag == dwarf::DW_TAG_const_type ||
Tag == dwarf::DW_TAG_volatile_type ||
Tag == dwarf::DW_TAG_restrict_type) {
uint32_t TmpTypeId;
visitTypeEntry(DTy->getBaseType(), TmpTypeId, CheckPointer,
SeenPointer);
}
}
}
return;
}
if (const auto *BTy = dyn_cast<DIBasicType>(Ty))
visitBasicType(BTy, TypeId);
else if (const auto *STy = dyn_cast<DISubroutineType>(Ty))
visitSubroutineType(STy, false, std::unordered_map<uint32_t, StringRef>(),
TypeId);
else if (const auto *CTy = dyn_cast<DICompositeType>(Ty))
visitCompositeType(CTy, TypeId);
else if (const auto *DTy = dyn_cast<DIDerivedType>(Ty))
visitDerivedType(DTy, TypeId, CheckPointer, SeenPointer);
else
llvm_unreachable("Unknown DIType");
}
void BTFDebug::visitTypeEntry(const DIType *Ty) {
uint32_t TypeId;
visitTypeEntry(Ty, TypeId, false, false);
}
void BTFDebug::visitMapDefType(const DIType *Ty, uint32_t &TypeId) {
if (!Ty || DIToIdMap.find(Ty) != DIToIdMap.end()) {
TypeId = DIToIdMap[Ty];
return;
}
// MapDef type may be a struct type or a non-pointer derived type
const DIType *OrigTy = Ty;
while (auto *DTy = dyn_cast<DIDerivedType>(Ty)) {
auto Tag = DTy->getTag();
if (Tag != dwarf::DW_TAG_typedef && Tag != dwarf::DW_TAG_const_type &&
Tag != dwarf::DW_TAG_volatile_type &&
Tag != dwarf::DW_TAG_restrict_type)
break;
Ty = DTy->getBaseType();
}
const auto *CTy = dyn_cast<DICompositeType>(Ty);
if (!CTy)
return;
auto Tag = CTy->getTag();
if (Tag != dwarf::DW_TAG_structure_type || CTy->isForwardDecl())
return;
// Visit all struct members to ensure pointee type is visited
const DINodeArray Elements = CTy->getElements();
for (const auto *Element : Elements) {
const auto *MemberType = cast<DIDerivedType>(Element);
visitTypeEntry(MemberType->getBaseType());
}
// Visit this type, struct or a const/typedef/volatile/restrict type
visitTypeEntry(OrigTy, TypeId, false, false);
}
/// Read file contents from the actual file or from the source
std::string BTFDebug::populateFileContent(const DISubprogram *SP) {
auto File = SP->getFile();
std::string FileName;
if (!File->getFilename().startswith("/") && File->getDirectory().size())
FileName = File->getDirectory().str() + "/" + File->getFilename().str();
else
FileName = std::string(File->getFilename());
// No need to populate the contends if it has been populated!
if (FileContent.find(FileName) != FileContent.end())
return FileName;
std::vector<std::string> Content;
std::string Line;
Content.push_back(Line); // Line 0 for empty string
std::unique_ptr<MemoryBuffer> Buf;
auto Source = File->getSource();
if (Source)
Buf = MemoryBuffer::getMemBufferCopy(*Source);
else if (ErrorOr<std::unique_ptr<MemoryBuffer>> BufOrErr =
MemoryBuffer::getFile(FileName))
Buf = std::move(*BufOrErr);
if (Buf)
for (line_iterator I(*Buf, false), E; I != E; ++I)
Content.push_back(std::string(*I));
FileContent[FileName] = Content;
return FileName;
}
void BTFDebug::constructLineInfo(const DISubprogram *SP, MCSymbol *Label,
uint32_t Line, uint32_t Column) {
std::string FileName = populateFileContent(SP);
BTFLineInfo LineInfo;
LineInfo.Label = Label;
LineInfo.FileNameOff = addString(FileName);
// If file content is not available, let LineOff = 0.
if (Line < FileContent[FileName].size())
LineInfo.LineOff = addString(FileContent[FileName][Line]);
else
LineInfo.LineOff = 0;
LineInfo.LineNum = Line;
LineInfo.ColumnNum = Column;
LineInfoTable[SecNameOff].push_back(LineInfo);
}
void BTFDebug::emitCommonHeader() {
OS.AddComment("0x" + Twine::utohexstr(BTF::MAGIC));
OS.emitIntValue(BTF::MAGIC, 2);
OS.emitInt8(BTF::VERSION);
OS.emitInt8(0);
}
void BTFDebug::emitBTFSection() {
// Do not emit section if no types and only "" string.
if (!TypeEntries.size() && StringTable.getSize() == 1)
return;
MCContext &Ctx = OS.getContext();
MCSectionELF *Sec = Ctx.getELFSection(".BTF", ELF::SHT_PROGBITS, 0);
Sec->setAlignment(Align(4));
OS.SwitchSection(Sec);
// Emit header.
emitCommonHeader();
OS.emitInt32(BTF::HeaderSize);
uint32_t TypeLen = 0, StrLen;
for (const auto &TypeEntry : TypeEntries)
TypeLen += TypeEntry->getSize();
StrLen = StringTable.getSize();
OS.emitInt32(0);
OS.emitInt32(TypeLen);
OS.emitInt32(TypeLen);
OS.emitInt32(StrLen);
// Emit type table.
for (const auto &TypeEntry : TypeEntries)
TypeEntry->emitType(OS);
// Emit string table.
uint32_t StringOffset = 0;
for (const auto &S : StringTable.getTable()) {
OS.AddComment("string offset=" + std::to_string(StringOffset));
OS.emitBytes(S);
OS.emitBytes(StringRef("\0", 1));
StringOffset += S.size() + 1;
}
}
void BTFDebug::emitBTFExtSection() {
// Do not emit section if empty FuncInfoTable and LineInfoTable
// and FieldRelocTable.
if (!FuncInfoTable.size() && !LineInfoTable.size() &&
!FieldRelocTable.size())
return;
MCContext &Ctx = OS.getContext();
MCSectionELF *Sec = Ctx.getELFSection(".BTF.ext", ELF::SHT_PROGBITS, 0);
Sec->setAlignment(Align(4));
OS.SwitchSection(Sec);
// Emit header.
emitCommonHeader();
OS.emitInt32(BTF::ExtHeaderSize);
// Account for FuncInfo/LineInfo record size as well.
uint32_t FuncLen = 4, LineLen = 4;
// Do not account for optional FieldReloc.
uint32_t FieldRelocLen = 0;
for (const auto &FuncSec : FuncInfoTable) {
FuncLen += BTF::SecFuncInfoSize;
FuncLen += FuncSec.second.size() * BTF::BPFFuncInfoSize;
}
for (const auto &LineSec : LineInfoTable) {
LineLen += BTF::SecLineInfoSize;
LineLen += LineSec.second.size() * BTF::BPFLineInfoSize;
}
for (const auto &FieldRelocSec : FieldRelocTable) {
FieldRelocLen += BTF::SecFieldRelocSize;
FieldRelocLen += FieldRelocSec.second.size() * BTF::BPFFieldRelocSize;
}
if (FieldRelocLen)
FieldRelocLen += 4;
OS.emitInt32(0);
OS.emitInt32(FuncLen);
OS.emitInt32(FuncLen);
OS.emitInt32(LineLen);
OS.emitInt32(FuncLen + LineLen);
OS.emitInt32(FieldRelocLen);
// Emit func_info table.
OS.AddComment("FuncInfo");
OS.emitInt32(BTF::BPFFuncInfoSize);
for (const auto &FuncSec : FuncInfoTable) {
OS.AddComment("FuncInfo section string offset=" +
std::to_string(FuncSec.first));
OS.emitInt32(FuncSec.first);
OS.emitInt32(FuncSec.second.size());
for (const auto &FuncInfo : FuncSec.second) {
Asm->emitLabelReference(FuncInfo.Label, 4);
OS.emitInt32(FuncInfo.TypeId);
}
}
// Emit line_info table.
OS.AddComment("LineInfo");
OS.emitInt32(BTF::BPFLineInfoSize);