aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm16/tools/dsymutil/DwarfLinkerForBinary.cpp
blob: 8df95f547e04bfdad8b35499c35af8ecf0f407eb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
//===- tools/dsymutil/DwarfLinkerForBinary.cpp ----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#include "DwarfLinkerForBinary.h"
#include "BinaryHolder.h"
#include "DebugMap.h"
#include "MachOUtils.h"
#include "dsymutil.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/BinaryFormat/MachO.h"
#include "llvm/BinaryFormat/Swift.h"
#include "llvm/CodeGen/AccelTable.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/DIE.h"
#include "llvm/CodeGen/NonRelocatableStringpool.h"
#include "llvm/Config/config.h"
#include "llvm/DWARFLinker/DWARFLinkerDeclContext.h"
#include "llvm/DebugInfo/DIContext.h"
#include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
#include "llvm/DebugInfo/DWARF/DWARFDie.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/DebugInfo/DWARF/DWARFSection.h"
#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/MC/MCTargetOptionsCommandFlags.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Object/MachO.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/DJB.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/ThreadPool.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/WithColor.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include <algorithm>
#include <cassert>
#include <cinttypes>
#include <climits>
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <limits>
#include <map>
#include <memory>
#include <optional>
#include <string>
#include <system_error>
#include <tuple>
#include <utility>
#include <vector>

namespace llvm {

static mc::RegisterMCTargetOptionsFlags MOF;

namespace dsymutil {

static Error copySwiftInterfaces(
    const std::map<std::string, std::string> &ParseableSwiftInterfaces,
    StringRef Architecture, const LinkOptions &Options) {
  std::error_code EC;
  SmallString<128> InputPath;
  SmallString<128> Path;
  sys::path::append(Path, *Options.ResourceDir, "Swift", Architecture);
  if ((EC = sys::fs::create_directories(Path.str(), true,
                                        sys::fs::perms::all_all)))
    return make_error<StringError>(
        "cannot create directory: " + toString(errorCodeToError(EC)), EC);
  unsigned BaseLength = Path.size();

  for (auto &I : ParseableSwiftInterfaces) {
    StringRef ModuleName = I.first;
    StringRef InterfaceFile = I.second;
    if (!Options.PrependPath.empty()) {
      InputPath.clear();
      sys::path::append(InputPath, Options.PrependPath, InterfaceFile);
      InterfaceFile = InputPath;
    }
    sys::path::append(Path, ModuleName);
    Path.append(".swiftinterface");
    if (Options.Verbose)
      outs() << "copy parseable Swift interface " << InterfaceFile << " -> "
             << Path.str() << '\n';

    // copy_file attempts an APFS clone first, so this should be cheap.
    if ((EC = sys::fs::copy_file(InterfaceFile, Path.str())))
      warn(Twine("cannot copy parseable Swift interface ") + InterfaceFile +
           ": " + toString(errorCodeToError(EC)));
    Path.resize(BaseLength);
  }
  return Error::success();
}

/// Report a warning to the user, optionally including information about a
/// specific \p DIE related to the warning.
void DwarfLinkerForBinary::reportWarning(const Twine &Warning,
                                         StringRef Context,
                                         const DWARFDie *DIE) const {

  warn(Warning, Context);

  if (!Options.Verbose || !DIE)
    return;

  DIDumpOptions DumpOpts;
  DumpOpts.ChildRecurseDepth = 0;
  DumpOpts.Verbose = Options.Verbose;

  WithColor::note() << "    in DIE:\n";
  DIE->dump(errs(), 6 /* Indent */, DumpOpts);
}

bool DwarfLinkerForBinary::createStreamer(const Triple &TheTriple,
                                          raw_fd_ostream &OutFile) {
  if (Options.NoOutput)
    return true;

  Streamer = std::make_unique<DwarfStreamer>(
      Options.FileType, OutFile, Options.Translator,
      [&](const Twine &Error, StringRef Context, const DWARFDie *) {
        error(Error, Context);
      },
      [&](const Twine &Warning, StringRef Context, const DWARFDie *) {
        warn(Warning, Context);
      });
  return Streamer->init(TheTriple, "__DWARF");
}

ErrorOr<const object::ObjectFile &>
DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
                                 const Triple &Triple) {
  auto ObjectEntry =
      BinHolder.getObjectEntry(Obj.getObjectFilename(), Obj.getTimestamp());
  if (!ObjectEntry) {
    auto Err = ObjectEntry.takeError();
    reportWarning(Twine(Obj.getObjectFilename()) + ": " +
                      toString(std::move(Err)),
                  Obj.getObjectFilename());
    return errorToErrorCode(std::move(Err));
  }

  auto Object = ObjectEntry->getObject(Triple);
  if (!Object) {
    auto Err = Object.takeError();
    reportWarning(Twine(Obj.getObjectFilename()) + ": " +
                      toString(std::move(Err)),
                  Obj.getObjectFilename());
    return errorToErrorCode(std::move(Err));
  }

  return *Object;
}

static Error remarksErrorHandler(const DebugMapObject &DMO,
                                 DwarfLinkerForBinary &Linker,
                                 std::unique_ptr<FileError> FE) {
  bool IsArchive = DMO.getObjectFilename().endswith(")");
  // Don't report errors for missing remark files from static
  // archives.
  if (!IsArchive)
    return Error(std::move(FE));

  std::string Message = FE->message();
  Error E = FE->takeError();
  Error NewE = handleErrors(std::move(E), [&](std::unique_ptr<ECError> EC) {
    if (EC->convertToErrorCode() != std::errc::no_such_file_or_directory)
      return Error(std::move(EC));

    Linker.reportWarning(Message, DMO.getObjectFilename());
    return Error(Error::success());
  });

  if (!NewE)
    return Error::success();

  return createFileError(FE->getFileName(), std::move(NewE));
}

static Error emitRemarks(const LinkOptions &Options, StringRef BinaryPath,
                         StringRef ArchName, const remarks::RemarkLinker &RL) {
  // Make sure we don't create the directories and the file if there is nothing
  // to serialize.
  if (RL.empty())
    return Error::success();

  SmallString<128> InputPath;
  SmallString<128> Path;
  // Create the "Remarks" directory in the "Resources" directory.
  sys::path::append(Path, *Options.ResourceDir, "Remarks");
  if (std::error_code EC = sys::fs::create_directories(Path.str(), true,
                                                       sys::fs::perms::all_all))
    return errorCodeToError(EC);

  // Append the file name.
  // For fat binaries, also append a dash and the architecture name.
  sys::path::append(Path, sys::path::filename(BinaryPath));
  if (Options.NumDebugMaps > 1) {
    // More than one debug map means we have a fat binary.
    Path += '-';
    Path += ArchName;
  }

  std::error_code EC;
  raw_fd_ostream OS(Options.NoOutput ? "-" : Path.str(), EC,
                    Options.RemarksFormat == remarks::Format::Bitstream
                        ? sys::fs::OF_None
                        : sys::fs::OF_Text);
  if (EC)
    return errorCodeToError(EC);

  if (Error E = RL.serialize(OS, Options.RemarksFormat))
    return E;

  return Error::success();
}

ErrorOr<DWARFFile &>
DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
                                 const DebugMap &DebugMap,
                                 remarks::RemarkLinker &RL) {
  auto ErrorOrObj = loadObject(Obj, DebugMap.getTriple());

  if (ErrorOrObj) {
    ContextForLinking.push_back(
        std::unique_ptr<DWARFContext>(DWARFContext::create(*ErrorOrObj)));
    AddressMapForLinking.push_back(
        std::make_unique<AddressManager>(*this, *ErrorOrObj, Obj));

    ObjectsForLinking.push_back(std::make_unique<DWARFFile>(
        Obj.getObjectFilename(), ContextForLinking.back().get(),
        AddressMapForLinking.back().get(),
        Obj.empty() ? Obj.getWarnings() : EmptyWarnings));

    Error E = RL.link(*ErrorOrObj);
    if (Error NewE = handleErrors(
            std::move(E), [&](std::unique_ptr<FileError> EC) -> Error {
              return remarksErrorHandler(Obj, *this, std::move(EC));
            }))
      return errorToErrorCode(std::move(NewE));

    return *ObjectsForLinking.back();
  }

  return ErrorOrObj.getError();
}

static bool binaryHasStrippableSwiftReflectionSections(
    const DebugMap &Map, const LinkOptions &Options, BinaryHolder &BinHolder) {
  // If the input binary has strippable swift5 reflection sections, there is no
  // need to copy them to the .dSYM. Only copy them for binaries where the
  // linker omitted the reflection metadata.
  if (!Map.getBinaryPath().empty() &&
      Options.FileType == OutputFileType::Object) {

    auto ObjectEntry = BinHolder.getObjectEntry(Map.getBinaryPath());
    // If ObjectEntry or Object has an error, no binary exists, therefore no
    // reflection sections exist.
    if (!ObjectEntry) {
      // Any errors will be diagnosed later in the main loop, ignore them here.
      llvm::consumeError(ObjectEntry.takeError());
      return false;
    }

    auto Object =
        ObjectEntry->getObjectAs<object::MachOObjectFile>(Map.getTriple());
    if (!Object) {
      // Any errors will be diagnosed later in the main loop, ignore them here.
      llvm::consumeError(Object.takeError());
      return false;
    }

    for (auto &Section : Object->sections()) {
      llvm::Expected<llvm::StringRef> NameOrErr =
          Object->getSectionName(Section.getRawDataRefImpl());
      if (!NameOrErr) {
        llvm::consumeError(NameOrErr.takeError());
        continue;
      }
      NameOrErr->consume_back("__TEXT");
      auto ReflectionSectionKind =
          Object->mapReflectionSectionNameToEnumValue(*NameOrErr);
      if (Object->isReflectionSectionStrippable(ReflectionSectionKind)) {
        return true;
      }
    }
  }
  return false;
}

/// Calculate the start of the strippable swift reflection sections in Dwarf.
/// Note that there's an assumption that the reflection sections will appear
/// in alphabetic order.
static std::vector<uint64_t>
calculateStartOfStrippableReflectionSections(const DebugMap &Map) {
  using llvm::binaryformat::Swift5ReflectionSectionKind;
  uint64_t AssocTySize = 0;
  uint64_t FieldMdSize = 0;
  for (const auto &Obj : Map.objects()) {
    auto OF =
        llvm::object::ObjectFile::createObjectFile(Obj->getObjectFilename());
    if (!OF) {
      llvm::consumeError(OF.takeError());
      continue;
    }
    if (auto *MO = dyn_cast<llvm::object::MachOObjectFile>(OF->getBinary())) {
      for (auto &Section : MO->sections()) {
        llvm::Expected<llvm::StringRef> NameOrErr =
            MO->getSectionName(Section.getRawDataRefImpl());
        if (!NameOrErr) {
          llvm::consumeError(NameOrErr.takeError());
          continue;
        }
        NameOrErr->consume_back("__TEXT");
        auto ReflSectionKind =
            MO->mapReflectionSectionNameToEnumValue(*NameOrErr);
        switch (ReflSectionKind) {
        case Swift5ReflectionSectionKind::assocty:
          AssocTySize += Section.getSize();
          break;
        case Swift5ReflectionSectionKind::fieldmd:
          FieldMdSize += Section.getSize();
          break;
        default:
          break;
        }
      }
    }
  }
  // Initialize the vector with enough space to fit every reflection section
  // kind.
  std::vector<uint64_t> SectionToOffset(Swift5ReflectionSectionKind::last, 0);
  SectionToOffset[Swift5ReflectionSectionKind::assocty] = 0;
  SectionToOffset[Swift5ReflectionSectionKind::fieldmd] =
      llvm::alignTo(AssocTySize, 4);
  SectionToOffset[Swift5ReflectionSectionKind::reflstr] = llvm::alignTo(
      SectionToOffset[Swift5ReflectionSectionKind::fieldmd] + FieldMdSize, 4);

  return SectionToOffset;
}

void DwarfLinkerForBinary::collectRelocationsToApplyToSwiftReflectionSections(
    const object::SectionRef &Section, StringRef &Contents,
    const llvm::object::MachOObjectFile *MO,
    const std::vector<uint64_t> &SectionToOffsetInDwarf,
    const llvm::dsymutil::DebugMapObject *Obj,
    std::vector<MachOUtils::DwarfRelocationApplicationInfo> &RelocationsToApply)
    const {
  for (auto It = Section.relocation_begin(); It != Section.relocation_end();
       ++It) {
    object::DataRefImpl RelocDataRef = It->getRawDataRefImpl();
    MachO::any_relocation_info MachOReloc = MO->getRelocation(RelocDataRef);

    if (!object::MachOObjectFile::isMachOPairedReloc(
            MO->getAnyRelocationType(MachOReloc), MO->getArch())) {
      reportWarning(
          "Unimplemented relocation type in strippable reflection section ",
          Obj->getObjectFilename());
      continue;
    }

    auto CalculateAddressOfSymbolInDwarfSegment =
        [&]() -> std::optional<int64_t> {
      auto Symbol = It->getSymbol();
      auto SymbolAbsoluteAddress = Symbol->getAddress();
      if (!SymbolAbsoluteAddress)
        return {};
      auto Section = Symbol->getSection();
      if (!Section) {
        llvm::consumeError(Section.takeError());
        return {};
      }

      if ((*Section)->getObject()->section_end() == *Section)
        return {};

      auto SectionStart = (*Section)->getAddress();
      auto SymbolAddressInSection = *SymbolAbsoluteAddress - SectionStart;
      auto SectionName = (*Section)->getName();
      if (!SectionName)
        return {};
      auto ReflSectionKind =
          MO->mapReflectionSectionNameToEnumValue(*SectionName);

      int64_t SectionStartInLinkedBinary =
          SectionToOffsetInDwarf[ReflSectionKind];

      auto Addr = SectionStartInLinkedBinary + SymbolAddressInSection;
      return Addr;
    };

    // The first symbol should always be in the section we're currently
    // iterating over.
    auto FirstSymbolAddress = CalculateAddressOfSymbolInDwarfSegment();
    ++It;

    bool ShouldSubtractDwarfVM = false;
    // For the second symbol there are two possibilities.
    std::optional<int64_t> SecondSymbolAddress;
    auto Sym = It->getSymbol();
    if (Sym != MO->symbol_end()) {
      Expected<StringRef> SymbolName = Sym->getName();
      if (SymbolName) {
        if (const auto *Mapping = Obj->lookupSymbol(*SymbolName)) {
          // First possibility: the symbol exists in the binary, and exists in a
          // non-strippable section (for example, typeref, or __TEXT,__const),
          // in which case we look up its address in the  binary, which dsymutil
          // will copy verbatim.
          SecondSymbolAddress = Mapping->getValue().BinaryAddress;
          // Since the symbols live in different segments, we have to substract
          // the start of the Dwarf's vmaddr so the value calculated points to
          // the correct place.
          ShouldSubtractDwarfVM = true;
        }
      }
    }

    if (!SecondSymbolAddress) {
      // Second possibility, this symbol is not present in the main binary, and
      // must be in one of the strippable sections (for example, reflstr).
      // Calculate its address in the same way as we did the first one.
      SecondSymbolAddress = CalculateAddressOfSymbolInDwarfSegment();
    }

    if (!FirstSymbolAddress || !SecondSymbolAddress)
      continue;

    auto SectionName = Section.getName();
    if (!SectionName)
      continue;

    int32_t Addend;
    memcpy(&Addend, Contents.data() + It->getOffset(), sizeof(int32_t));
    int32_t Value = (*SecondSymbolAddress + Addend) - *FirstSymbolAddress;
    auto ReflSectionKind =
        MO->mapReflectionSectionNameToEnumValue(*SectionName);
    uint64_t AddressFromDwarfVM =
        SectionToOffsetInDwarf[ReflSectionKind] + It->getOffset();
    RelocationsToApply.emplace_back(AddressFromDwarfVM, Value,
                                    ShouldSubtractDwarfVM);
  }
}

void DwarfLinkerForBinary::copySwiftReflectionMetadata(
    const llvm::dsymutil::DebugMapObject *Obj, DwarfStreamer *Streamer,
    std::vector<uint64_t> &SectionToOffsetInDwarf,
    std::vector<MachOUtils::DwarfRelocationApplicationInfo>
        &RelocationsToApply) {
  using binaryformat::Swift5ReflectionSectionKind;
  auto OF =
      llvm::object::ObjectFile::createObjectFile(Obj->getObjectFilename());
  if (!OF) {
    llvm::consumeError(OF.takeError());
    return;
  }
  if (auto *MO = dyn_cast<llvm::object::MachOObjectFile>(OF->getBinary())) {
    // Collect the swift reflection sections before emitting them. This is
    // done so we control the order they're emitted.
    std::array<std::optional<object::SectionRef>,
               Swift5ReflectionSectionKind::last + 1>
        SwiftSections;
    for (auto &Section : MO->sections()) {
      llvm::Expected<llvm::StringRef> NameOrErr =
          MO->getSectionName(Section.getRawDataRefImpl());
      if (!NameOrErr) {
        llvm::consumeError(NameOrErr.takeError());
        continue;
      }
      NameOrErr->consume_back("__TEXT");
      auto ReflSectionKind =
          MO->mapReflectionSectionNameToEnumValue(*NameOrErr);
      if (MO->isReflectionSectionStrippable(ReflSectionKind))
        SwiftSections[ReflSectionKind] = Section;
    }
    // Make sure we copy the sections in alphabetic order.
    auto SectionKindsToEmit = {Swift5ReflectionSectionKind::assocty,
                               Swift5ReflectionSectionKind::fieldmd,
                               Swift5ReflectionSectionKind::reflstr};
    for (auto SectionKind : SectionKindsToEmit) {
      if (!SwiftSections[SectionKind])
        continue;
      auto &Section = *SwiftSections[SectionKind];
      llvm::Expected<llvm::StringRef> SectionContents = Section.getContents();
      if (!SectionContents)
        continue;
      const auto *MO =
          llvm::cast<llvm::object::MachOObjectFile>(Section.getObject());
      collectRelocationsToApplyToSwiftReflectionSections(
          Section, *SectionContents, MO, SectionToOffsetInDwarf, Obj,
          RelocationsToApply);
      // Update the section start with the current section's contribution, so
      // the next section we copy from a different .o file points to the correct
      // place.
      SectionToOffsetInDwarf[SectionKind] += Section.getSize();
      Streamer->emitSwiftReflectionSection(SectionKind, *SectionContents,
                                           Section.getAlignment().value(),
                                           Section.getSize());
    }
  }
}

bool DwarfLinkerForBinary::link(const DebugMap &Map) {
  if (!createStreamer(Map.getTriple(), OutFile))
    return false;

  ObjectsForLinking.clear();
  ContextForLinking.clear();
  AddressMapForLinking.clear();

  DebugMap DebugMap(Map.getTriple(), Map.getBinaryPath());

  DWARFLinker GeneralLinker(Streamer.get(), DwarfLinkerClient::Dsymutil);

  remarks::RemarkLinker RL;
  if (!Options.RemarksPrependPath.empty())
    RL.setExternalFilePrependPath(Options.RemarksPrependPath);
  GeneralLinker.setObjectPrefixMap(&Options.ObjectPrefixMap);

  std::function<StringRef(StringRef)> TranslationLambda = [&](StringRef Input) {
    assert(Options.Translator);
    return Options.Translator(Input);
  };

  GeneralLinker.setVerbosity(Options.Verbose);
  GeneralLinker.setStatistics(Options.Statistics);
  GeneralLinker.setVerifyInputDWARF(Options.VerifyInputDWARF);
  GeneralLinker.setNoOutput(Options.NoOutput);
  GeneralLinker.setNoODR(Options.NoODR);
  GeneralLinker.setUpdate(Options.Update);
  GeneralLinker.setNumThreads(Options.Threads);
  GeneralLinker.setPrependPath(Options.PrependPath);
  GeneralLinker.setKeepFunctionForStatic(Options.KeepFunctionForStatic);
  if (Options.Translator)
    GeneralLinker.setStringsTranslator(TranslationLambda);
  GeneralLinker.setWarningHandler(
      [&](const Twine &Warning, StringRef Context, const DWARFDie *DIE) {
        reportWarning(Warning, Context, DIE);
      });
  GeneralLinker.setErrorHandler(
      [&](const Twine &Error, StringRef Context, const DWARFDie *) {
        error(Error, Context);
      });
  objFileLoader Loader = [&DebugMap, &RL,
                          this](StringRef ContainerName,
                                StringRef Path) -> ErrorOr<DWARFFile &> {
    auto &Obj = DebugMap.addDebugMapObject(
        Path, sys::TimePoint<std::chrono::seconds>(), MachO::N_OSO);

    if (auto ErrorOrObj = loadObject(Obj, DebugMap, RL)) {
      return *ErrorOrObj;
    } else {
      // Try and emit more helpful warnings by applying some heuristics.
      StringRef ObjFile = ContainerName;
      bool IsClangModule = sys::path::extension(Path).equals(".pcm");
      bool IsArchive = ObjFile.endswith(")");

      if (IsClangModule) {
        StringRef ModuleCacheDir = sys::path::parent_path(Path);
        if (sys::fs::exists(ModuleCacheDir)) {
          // If the module's parent directory exists, we assume that the
          // module cache has expired and was pruned by clang.  A more
          // adventurous dsymutil would invoke clang to rebuild the module
          // now.
          if (!ModuleCacheHintDisplayed) {
            WithColor::note()
                << "The clang module cache may have expired since "
                   "this object file was built. Rebuilding the "
                   "object file will rebuild the module cache.\n";
            ModuleCacheHintDisplayed = true;
          }
        } else if (IsArchive) {
          // If the module cache directory doesn't exist at all and the
          // object file is inside a static library, we assume that the
          // static library was built on a different machine. We don't want
          // to discourage module debugging for convenience libraries within
          // a project though.
          if (!ArchiveHintDisplayed) {
            WithColor::note()
                << "Linking a static library that was built with "
                   "-gmodules, but the module cache was not found.  "
                   "Redistributable static libraries should never be "
                   "built with module debugging enabled.  The debug "
                   "experience will be degraded due to incomplete "
                   "debug information.\n";
            ArchiveHintDisplayed = true;
          }
        }
      }

      return ErrorOrObj.getError();
    }

    llvm_unreachable("Unhandled DebugMap object");
  };
  GeneralLinker.setSwiftInterfacesMap(&ParseableSwiftInterfaces);
  bool ReflectionSectionsPresentInBinary = false;
  // If there is no output specified, no point in checking the binary for swift5
  // reflection sections.
  if (!Options.NoOutput) {
    ReflectionSectionsPresentInBinary =
        binaryHasStrippableSwiftReflectionSections(Map, Options, BinHolder);
  }

  std::vector<MachOUtils::DwarfRelocationApplicationInfo> RelocationsToApply;
  if (!Options.NoOutput && !ReflectionSectionsPresentInBinary) {
    auto SectionToOffsetInDwarf =
        calculateStartOfStrippableReflectionSections(Map);
    for (const auto &Obj : Map.objects()) 
      copySwiftReflectionMetadata(Obj.get(), Streamer.get(),
                                  SectionToOffsetInDwarf, RelocationsToApply);
  }

  uint16_t MaxDWARFVersion = 0;
  std::function<void(const DWARFUnit &Unit)> OnCUDieLoaded =
      [&MaxDWARFVersion](const DWARFUnit &Unit) {
        MaxDWARFVersion = std::max(Unit.getVersion(), MaxDWARFVersion);
      };

  for (const auto &Obj : Map.objects()) {
    // N_AST objects (swiftmodule files) should get dumped directly into the
    // appropriate DWARF section.
    if (Obj->getType() == MachO::N_AST) {
      if (Options.Verbose)
        outs() << "DEBUG MAP OBJECT: " << Obj->getObjectFilename() << "\n";

      StringRef File = Obj->getObjectFilename();
      auto ErrorOrMem = MemoryBuffer::getFile(File);
      if (!ErrorOrMem) {
        warn("Could not open '" + File + "'\n");
        continue;
      }
      sys::fs::file_status Stat;
      if (auto Err = sys::fs::status(File, Stat)) {
        warn(Err.message());
        continue;
      }
      if (!Options.NoTimestamp) {
        // The modification can have sub-second precision so we need to cast
        // away the extra precision that's not present in the debug map.
        auto ModificationTime =
            std::chrono::time_point_cast<std::chrono::seconds>(
                Stat.getLastModificationTime());
        if (Obj->getTimestamp() != sys::TimePoint<>() &&
            ModificationTime != Obj->getTimestamp()) {
          // Not using the helper here as we can easily stream TimePoint<>.
          WithColor::warning()
              << File << ": timestamp mismatch between swift interface file ("
              << sys::TimePoint<>(ModificationTime) << ") and debug map ("
              << sys::TimePoint<>(Obj->getTimestamp()) << ")\n";
          continue;
        }
      }

      // Copy the module into the .swift_ast section.
      if (!Options.NoOutput)
        Streamer->emitSwiftAST((*ErrorOrMem)->getBuffer());

      continue;
    }

    if (auto ErrorOrObj = loadObject(*Obj, Map, RL))
      GeneralLinker.addObjectFile(*ErrorOrObj, Loader, OnCUDieLoaded);
    else {
      ObjectsForLinking.push_back(std::make_unique<DWARFFile>(
          Obj->getObjectFilename(), nullptr, nullptr,
          Obj->empty() ? Obj->getWarnings() : EmptyWarnings));
      GeneralLinker.addObjectFile(*ObjectsForLinking.back());
    }
  }

  // If we haven't seen any CUs, pick an arbitrary valid Dwarf version anyway.
  if (MaxDWARFVersion == 0)
    MaxDWARFVersion = 3;

  if (Error E = GeneralLinker.setTargetDWARFVersion(MaxDWARFVersion))
    return error(toString(std::move(E)));

  switch (Options.TheAccelTableKind) {
  case DsymutilAccelTableKind::Apple:
    GeneralLinker.addAccelTableKind(DwarfLinkerAccelTableKind::Apple);
    break;
  case DsymutilAccelTableKind::Dwarf:
    GeneralLinker.addAccelTableKind(DwarfLinkerAccelTableKind::DebugNames);
    break;
  case DsymutilAccelTableKind::Pub:
    GeneralLinker.addAccelTableKind(DwarfLinkerAccelTableKind::Pub);
    break;
  case DsymutilAccelTableKind::Default:
    if (MaxDWARFVersion >= 5)
      GeneralLinker.addAccelTableKind(DwarfLinkerAccelTableKind::DebugNames);
    else
      GeneralLinker.addAccelTableKind(DwarfLinkerAccelTableKind::Apple);
    break;
  case DsymutilAccelTableKind::None:
    // Nothing to do.
    break;
  }

  // link debug info for loaded object files.
  if (Error E = GeneralLinker.link())
    return error(toString(std::move(E)));

  StringRef ArchName = Map.getTriple().getArchName();
  if (Error E = emitRemarks(Options, Map.getBinaryPath(), ArchName, RL))
    return error(toString(std::move(E)));

  if (Options.NoOutput)
    return true;

  if (Options.ResourceDir && !ParseableSwiftInterfaces.empty()) {
    StringRef ArchName = Triple::getArchTypeName(Map.getTriple().getArch());
    if (auto E =
            copySwiftInterfaces(ParseableSwiftInterfaces, ArchName, Options))
      return error(toString(std::move(E)));
  }

  if (Map.getTriple().isOSDarwin() && !Map.getBinaryPath().empty() &&
      Options.FileType == OutputFileType::Object)
    return MachOUtils::generateDsymCompanion(
        Options.VFS, Map, Options.Translator,
        *Streamer->getAsmPrinter().OutStreamer, OutFile, RelocationsToApply);

  Streamer->finish();
  return true;
}

/// Iterate over the relocations of the given \p Section and
/// store the ones that correspond to debug map entries into the
/// ValidRelocs array.
void DwarfLinkerForBinary::AddressManager::findValidRelocsMachO(
    const object::SectionRef &Section, const object::MachOObjectFile &Obj,
    const DebugMapObject &DMO, std::vector<ValidReloc> &ValidRelocs) {
  Expected<StringRef> ContentsOrErr = Section.getContents();
  if (!ContentsOrErr) {
    consumeError(ContentsOrErr.takeError());
    Linker.reportWarning("error reading section", DMO.getObjectFilename());
    return;
  }
  DataExtractor Data(*ContentsOrErr, Obj.isLittleEndian(), 0);
  bool SkipNext = false;

  for (const object::RelocationRef &Reloc : Section.relocations()) {
    if (SkipNext) {
      SkipNext = false;
      continue;
    }

    object::DataRefImpl RelocDataRef = Reloc.getRawDataRefImpl();
    MachO::any_relocation_info MachOReloc = Obj.getRelocation(RelocDataRef);

    if (object::MachOObjectFile::isMachOPairedReloc(Obj.getAnyRelocationType(MachOReloc),
                           Obj.getArch())) {
      SkipNext = true;
      Linker.reportWarning("unsupported relocation in " + *Section.getName() +
                               " section.",
                           DMO.getObjectFilename());
      continue;
    }

    unsigned RelocSize = 1 << Obj.getAnyRelocationLength(MachOReloc);
    uint64_t Offset64 = Reloc.getOffset();
    if ((RelocSize != 4 && RelocSize != 8)) {
      Linker.reportWarning("unsupported relocation in " + *Section.getName() +
                               " section.",
                           DMO.getObjectFilename());
      continue;
    }
    uint64_t OffsetCopy = Offset64;
    // Mach-o uses REL relocations, the addend is at the relocation offset.
    uint64_t Addend = Data.getUnsigned(&OffsetCopy, RelocSize);
    uint64_t SymAddress;
    int64_t SymOffset;

    if (Obj.isRelocationScattered(MachOReloc)) {
      // The address of the base symbol for scattered relocations is
      // stored in the reloc itself. The actual addend will store the
      // base address plus the offset.
      SymAddress = Obj.getScatteredRelocationValue(MachOReloc);
      SymOffset = int64_t(Addend) - SymAddress;
    } else {
      SymAddress = Addend;
      SymOffset = 0;
    }

    auto Sym = Reloc.getSymbol();
    if (Sym != Obj.symbol_end()) {
      Expected<StringRef> SymbolName = Sym->getName();
      if (!SymbolName) {
        consumeError(SymbolName.takeError());
        Linker.reportWarning("error getting relocation symbol name.",
                             DMO.getObjectFilename());
        continue;
      }
      if (const auto *Mapping = DMO.lookupSymbol(*SymbolName))
        ValidRelocs.emplace_back(Offset64, RelocSize, Addend, Mapping);
    } else if (const auto *Mapping = DMO.lookupObjectAddress(SymAddress)) {
      // Do not store the addend. The addend was the address of the symbol in
      // the object file, the address in the binary that is stored in the debug
      // map doesn't need to be offset.
      ValidRelocs.emplace_back(Offset64, RelocSize, SymOffset, Mapping);
    }
  }
}

/// Dispatch the valid relocation finding logic to the
/// appropriate handler depending on the object file format.
bool DwarfLinkerForBinary::AddressManager::findValidRelocs(
    const object::SectionRef &Section, const object::ObjectFile &Obj,
    const DebugMapObject &DMO, std::vector<ValidReloc> &Relocs) {
  // Dispatch to the right handler depending on the file type.
  if (auto *MachOObj = dyn_cast<object::MachOObjectFile>(&Obj))
    findValidRelocsMachO(Section, *MachOObj, DMO, Relocs);
  else
    Linker.reportWarning(Twine("unsupported object file type: ") +
                             Obj.getFileName(),
                         DMO.getObjectFilename());
  if (Relocs.empty())
    return false;

  // Sort the relocations by offset. We will walk the DIEs linearly in
  // the file, this allows us to just keep an index in the relocation
  // array that we advance during our walk, rather than resorting to
  // some associative container. See DwarfLinkerForBinary::NextValidReloc.
  llvm::sort(Relocs);
  return true;
}

/// Look for relocations in the debug_info and debug_addr section that match
/// entries in the debug map. These relocations will drive the Dwarf link by
/// indicating which DIEs refer to symbols present in the linked binary.
/// \returns whether there are any valid relocations in the debug info.
bool DwarfLinkerForBinary::AddressManager::findValidRelocsInDebugSections(
    const object::ObjectFile &Obj, const DebugMapObject &DMO) {
  // Find the debug_info section.
  bool FoundValidRelocs = false;
  for (const object::SectionRef &Section : Obj.sections()) {
    StringRef SectionName;
    if (Expected<StringRef> NameOrErr = Section.getName())
      SectionName = *NameOrErr;
    else
      consumeError(NameOrErr.takeError());

    SectionName = SectionName.substr(SectionName.find_first_not_of("._"));
    if (SectionName == "debug_info")
      FoundValidRelocs |=
          findValidRelocs(Section, Obj, DMO, ValidDebugInfoRelocs);
    if (SectionName == "debug_addr")
      FoundValidRelocs |=
          findValidRelocs(Section, Obj, DMO, ValidDebugAddrRelocs);
  }
  return FoundValidRelocs;
}

std::vector<DwarfLinkerForBinary::AddressManager::ValidReloc>
DwarfLinkerForBinary::AddressManager::getRelocations(
    const std::vector<ValidReloc> &Relocs, uint64_t StartPos, uint64_t EndPos) {
  std::vector<DwarfLinkerForBinary::AddressManager::ValidReloc> Res;

  auto CurReloc = partition_point(Relocs, [StartPos](const ValidReloc &Reloc) {
    return Reloc.Offset < StartPos;
  });

  while (CurReloc != Relocs.end() && CurReloc->Offset >= StartPos &&
         CurReloc->Offset < EndPos) {
    Res.push_back(*CurReloc);
    CurReloc++;
  }

  return Res;
}

void DwarfLinkerForBinary::AddressManager::printReloc(const ValidReloc &Reloc) {
  const auto &Mapping = Reloc.Mapping->getValue();
  const uint64_t ObjectAddress = Mapping.ObjectAddress
                                     ? uint64_t(*Mapping.ObjectAddress)
                                     : std::numeric_limits<uint64_t>::max();

  outs() << "Found valid debug map entry: " << Reloc.Mapping->getKey() << "\t"
         << format("0x%016" PRIx64 " => 0x%016" PRIx64 "\n", ObjectAddress,
                   uint64_t(Mapping.BinaryAddress));
}

void DwarfLinkerForBinary::AddressManager::fillDieInfo(
    const ValidReloc &Reloc, CompileUnit::DIEInfo &Info) {
  Info.AddrAdjust = relocate(Reloc);
  if (Reloc.Mapping->getValue().ObjectAddress)
    Info.AddrAdjust -= uint64_t(*Reloc.Mapping->getValue().ObjectAddress);
  Info.InDebugMap = true;
}

bool DwarfLinkerForBinary::AddressManager::hasValidRelocationAt(
    const std::vector<ValidReloc> &AllRelocs, uint64_t StartOffset,
    uint64_t EndOffset, CompileUnit::DIEInfo &Info) {
  std::vector<ValidReloc> Relocs =
      getRelocations(AllRelocs, StartOffset, EndOffset);

  if (Relocs.size() == 0)
    return false;

  if (Linker.Options.Verbose)
    printReloc(Relocs[0]);
  fillDieInfo(Relocs[0], Info);

  return true;
}

/// Get the starting and ending (exclusive) offset for the
/// attribute with index \p Idx descibed by \p Abbrev. \p Offset is
/// supposed to point to the position of the first attribute described
/// by \p Abbrev.
/// \return [StartOffset, EndOffset) as a pair.
static std::pair<uint64_t, uint64_t>
getAttributeOffsets(const DWARFAbbreviationDeclaration *Abbrev, unsigned Idx,
                    uint64_t Offset, const DWARFUnit &Unit) {
  DataExtractor Data = Unit.getDebugInfoExtractor();

  for (unsigned I = 0; I < Idx; ++I)
    DWARFFormValue::skipValue(Abbrev->getFormByIndex(I), Data, &Offset,
                              Unit.getFormParams());

  uint64_t End = Offset;
  DWARFFormValue::skipValue(Abbrev->getFormByIndex(Idx), Data, &End,
                            Unit.getFormParams());

  return std::make_pair(Offset, End);
}

bool DwarfLinkerForBinary::AddressManager::isLiveVariable(
    const DWARFDie &DIE, CompileUnit::DIEInfo &MyInfo) {
  const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();

  std::optional<uint32_t> LocationIdx =
      Abbrev->findAttributeIndex(dwarf::DW_AT_location);
  if (!LocationIdx)
    return false;

  uint64_t Offset = DIE.getOffset() + getULEB128Size(Abbrev->getCode());
  uint64_t LocationOffset, LocationEndOffset;
  std::tie(LocationOffset, LocationEndOffset) =
      getAttributeOffsets(Abbrev, *LocationIdx, Offset, *DIE.getDwarfUnit());

  // FIXME: Support relocations debug_addr.
  return hasValidRelocationAt(ValidDebugInfoRelocs, LocationOffset,
                              LocationEndOffset, MyInfo);
}

bool DwarfLinkerForBinary::AddressManager::isLiveSubprogram(
    const DWARFDie &DIE, CompileUnit::DIEInfo &MyInfo) {
  const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();

  std::optional<uint32_t> LowPcIdx =
      Abbrev->findAttributeIndex(dwarf::DW_AT_low_pc);
  if (!LowPcIdx)
    return false;

  dwarf::Form Form = Abbrev->getFormByIndex(*LowPcIdx);

  if (Form == dwarf::DW_FORM_addr) {
    uint64_t Offset = DIE.getOffset() + getULEB128Size(Abbrev->getCode());
    uint64_t LowPcOffset, LowPcEndOffset;
    std::tie(LowPcOffset, LowPcEndOffset) =
        getAttributeOffsets(Abbrev, *LowPcIdx, Offset, *DIE.getDwarfUnit());
    return hasValidRelocationAt(ValidDebugInfoRelocs, LowPcOffset,
                                LowPcEndOffset, MyInfo);
  }

  if (Form == dwarf::DW_FORM_addrx) {
    std::optional<DWARFFormValue> AddrValue = DIE.find(dwarf::DW_AT_low_pc);
    if (std::optional<uint64_t> AddrOffsetSectionBase =
            DIE.getDwarfUnit()->getAddrOffsetSectionBase()) {
      uint64_t StartOffset = *AddrOffsetSectionBase + AddrValue->getRawUValue();
      uint64_t EndOffset =
          StartOffset + DIE.getDwarfUnit()->getAddressByteSize();
      return hasValidRelocationAt(ValidDebugAddrRelocs, StartOffset, EndOffset,
                                  MyInfo);
    } else
      Linker.reportWarning("no base offset for address table", SrcFileName);
  }

  return false;
}

uint64_t
DwarfLinkerForBinary::AddressManager::relocate(const ValidReloc &Reloc) const {
  return Reloc.Mapping->getValue().BinaryAddress + Reloc.Addend;
}

/// Apply the valid relocations found by findValidRelocs() to
/// the buffer \p Data, taking into account that Data is at \p BaseOffset
/// in the debug_info section.
///
/// Like for findValidRelocs(), this function must be called with
/// monotonic \p BaseOffset values.
///
/// \returns whether any reloc has been applied.
bool DwarfLinkerForBinary::AddressManager::applyValidRelocs(
    MutableArrayRef<char> Data, uint64_t BaseOffset, bool IsLittleEndian) {
  std::vector<ValidReloc> Relocs = getRelocations(
      ValidDebugInfoRelocs, BaseOffset, BaseOffset + Data.size());

  for (const ValidReloc &CurReloc : Relocs) {
    assert(CurReloc.Offset - BaseOffset < Data.size());
    assert(CurReloc.Offset - BaseOffset + CurReloc.Size <= Data.size());
    char Buf[8];
    uint64_t Value = relocate(CurReloc);
    for (unsigned I = 0; I != CurReloc.Size; ++I) {
      unsigned Index = IsLittleEndian ? I : (CurReloc.Size - I - 1);
      Buf[I] = uint8_t(Value >> (Index * 8));
    }
    assert(CurReloc.Size <= sizeof(Buf));
    memcpy(&Data[CurReloc.Offset - BaseOffset], Buf, CurReloc.Size);
  }

  return Relocs.size() > 0;
}

llvm::Expected<uint64_t>
DwarfLinkerForBinary::AddressManager::relocateIndexedAddr(uint64_t StartOffset,
                                                          uint64_t EndOffset) {
  std::vector<ValidReloc> Relocs =
      getRelocations(ValidDebugAddrRelocs, StartOffset, EndOffset);
  if (Relocs.size() == 0)
    return createStringError(
        std::make_error_code(std::errc::invalid_argument),
        "no relocation for offset %llu in debug_addr section", StartOffset);

  return relocate(Relocs[0]);
}

bool linkDwarf(raw_fd_ostream &OutFile, BinaryHolder &BinHolder,
               const DebugMap &DM, LinkOptions Options) {
  DwarfLinkerForBinary Linker(OutFile, BinHolder, std::move(Options));
  return Linker.link(DM);
}

} // namespace dsymutil
} // namespace llvm