File: LVBinaryReader.cpp

package info (click to toggle)
llvm-toolchain-16 1%3A16.0.6-15~deb12u1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,634,792 kB
  • sloc: cpp: 6,179,261; ansic: 1,216,205; asm: 741,319; python: 196,614; objc: 75,325; f90: 49,640; lisp: 32,396; pascal: 12,286; sh: 9,394; perl: 7,442; ml: 5,494; awk: 3,523; makefile: 2,723; javascript: 1,206; xml: 886; fortran: 581; cs: 573
file content (821 lines) | stat: -rw-r--r-- 31,824 bytes parent folder | download | duplicates (7)
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
//===-- LVBinaryReader.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
//
//===----------------------------------------------------------------------===//
//
// This implements the LVBinaryReader class.
//
//===----------------------------------------------------------------------===//

#include "llvm/DebugInfo/LogicalView/Readers/LVBinaryReader.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/FormatAdapters.h"
#include "llvm/Support/FormatVariadic.h"

using namespace llvm;
using namespace llvm::logicalview;

#define DEBUG_TYPE "BinaryReader"

// Function names extracted from the object symbol table.
void LVSymbolTable::add(StringRef Name, LVScope *Function,
                        LVSectionIndex SectionIndex) {
  std::string SymbolName(Name);
  if (SymbolNames.find(SymbolName) == SymbolNames.end()) {
    SymbolNames.emplace(
        std::piecewise_construct, std::forward_as_tuple(SymbolName),
        std::forward_as_tuple(Function, 0, SectionIndex, false));
  } else {
    // Update a recorded entry with its logical scope and section index.
    SymbolNames[SymbolName].Scope = Function;
    if (SectionIndex)
      SymbolNames[SymbolName].SectionIndex = SectionIndex;
  }

  if (Function && SymbolNames[SymbolName].IsComdat)
    Function->setIsComdat();

  LLVM_DEBUG({ print(dbgs()); });
}

void LVSymbolTable::add(StringRef Name, LVAddress Address,
                        LVSectionIndex SectionIndex, bool IsComdat) {
  std::string SymbolName(Name);
  if (SymbolNames.find(SymbolName) == SymbolNames.end())
    SymbolNames.emplace(
        std::piecewise_construct, std::forward_as_tuple(SymbolName),
        std::forward_as_tuple(nullptr, Address, SectionIndex, IsComdat));
  else
    // Update a recorded symbol name with its logical scope.
    SymbolNames[SymbolName].Address = Address;

  LVScope *Function = SymbolNames[SymbolName].Scope;
  if (Function && IsComdat)
    Function->setIsComdat();
  LLVM_DEBUG({ print(dbgs()); });
}

LVSectionIndex LVSymbolTable::update(LVScope *Function) {
  LVSectionIndex SectionIndex = getReader().getDotTextSectionIndex();
  StringRef Name = Function->getLinkageName();
  if (Name.empty())
    Name = Function->getName();
  std::string SymbolName(Name);

  if (SymbolName.empty() || (SymbolNames.find(SymbolName) == SymbolNames.end()))
    return SectionIndex;

  // Update a recorded entry with its logical scope, only if the scope has
  // ranges. That is the case when in DWARF there are 2 DIEs connected via
  // the DW_AT_specification.
  if (Function->getHasRanges()) {
    SymbolNames[SymbolName].Scope = Function;
    SectionIndex = SymbolNames[SymbolName].SectionIndex;
  } else {
    SectionIndex = UndefinedSectionIndex;
  }

  if (SymbolNames[SymbolName].IsComdat)
    Function->setIsComdat();

  LLVM_DEBUG({ print(dbgs()); });
  return SectionIndex;
}

const LVSymbolTableEntry &LVSymbolTable::getEntry(StringRef Name) {
  static LVSymbolTableEntry Empty = LVSymbolTableEntry();
  LVSymbolNames::iterator Iter = SymbolNames.find(std::string(Name));
  return Iter != SymbolNames.end() ? Iter->second : Empty;
}
LVAddress LVSymbolTable::getAddress(StringRef Name) {
  LVSymbolNames::iterator Iter = SymbolNames.find(std::string(Name));
  return Iter != SymbolNames.end() ? Iter->second.Address : 0;
}
LVSectionIndex LVSymbolTable::getIndex(StringRef Name) {
  LVSymbolNames::iterator Iter = SymbolNames.find(std::string(Name));
  return Iter != SymbolNames.end() ? Iter->second.SectionIndex
                                   : getReader().getDotTextSectionIndex();
}
bool LVSymbolTable::getIsComdat(StringRef Name) {
  LVSymbolNames::iterator Iter = SymbolNames.find(std::string(Name));
  return Iter != SymbolNames.end() ? Iter->second.IsComdat : false;
}

void LVSymbolTable::print(raw_ostream &OS) {
  OS << "Symbol Table\n";
  for (LVSymbolNames::reference Entry : SymbolNames) {
    LVSymbolTableEntry &SymbolName = Entry.second;
    LVScope *Scope = SymbolName.Scope;
    LVOffset Offset = Scope ? Scope->getOffset() : 0;
    OS << "Index: " << hexValue(SymbolName.SectionIndex, 5)
       << " Comdat: " << (SymbolName.IsComdat ? "Y" : "N")
       << " Scope: " << hexValue(Offset)
       << " Address: " << hexValue(SymbolName.Address)
       << " Name: " << Entry.first << "\n";
  }
}

void LVBinaryReader::addToSymbolTable(StringRef Name, LVScope *Function,
                                      LVSectionIndex SectionIndex) {
  SymbolTable.add(Name, Function, SectionIndex);
}
void LVBinaryReader::addToSymbolTable(StringRef Name, LVAddress Address,
                                      LVSectionIndex SectionIndex,
                                      bool IsComdat) {
  SymbolTable.add(Name, Address, SectionIndex, IsComdat);
}
LVSectionIndex LVBinaryReader::updateSymbolTable(LVScope *Function) {
  return SymbolTable.update(Function);
}

const LVSymbolTableEntry &LVBinaryReader::getSymbolTableEntry(StringRef Name) {
  return SymbolTable.getEntry(Name);
}
LVAddress LVBinaryReader::getSymbolTableAddress(StringRef Name) {
  return SymbolTable.getAddress(Name);
}
LVSectionIndex LVBinaryReader::getSymbolTableIndex(StringRef Name) {
  return SymbolTable.getIndex(Name);
}
bool LVBinaryReader::getSymbolTableIsComdat(StringRef Name) {
  return SymbolTable.getIsComdat(Name);
}

void LVBinaryReader::mapVirtualAddress(const object::ObjectFile &Obj) {
  for (const object::SectionRef &Section : Obj.sections()) {
    if (!Section.isText() || Section.isVirtual() || !Section.getSize())
      continue;

    // Record section information required for symbol resolution.
    // Note: The section index returned by 'getIndex()' is one based.
    Sections.emplace(Section.getIndex(), Section);
    addSectionAddress(Section);

    // Identify the ".text" section.
    Expected<StringRef> SectionNameOrErr = Section.getName();
    if (!SectionNameOrErr) {
      consumeError(SectionNameOrErr.takeError());
      continue;
    }
    if ((*SectionNameOrErr).equals(".text") ||
        (*SectionNameOrErr).equals(".code"))
      DotTextSectionIndex = Section.getIndex();
  }

  // Process the symbol table.
  mapRangeAddress(Obj);

  LLVM_DEBUG({
    dbgs() << "\nSections Information:\n";
    for (LVSections::reference Entry : Sections) {
      LVSectionIndex SectionIndex = Entry.first;
      const object::SectionRef Section = Entry.second;
      Expected<StringRef> SectionNameOrErr = Section.getName();
      if (!SectionNameOrErr)
        consumeError(SectionNameOrErr.takeError());
      dbgs() << "\nIndex: " << format_decimal(SectionIndex, 3)
             << " Name: " << *SectionNameOrErr << "\n"
             << "Size: " << hexValue(Section.getSize()) << "\n"
             << "VirtualAddress: " << hexValue(VirtualAddress) << "\n"
             << "SectionAddress: " << hexValue(Section.getAddress()) << "\n";
    }
    dbgs() << "\nObject Section Information:\n";
    for (LVSectionAddresses::const_reference Entry : SectionAddresses)
      dbgs() << "[" << hexValue(Entry.first) << ":"
             << hexValue(Entry.first + Entry.second.getSize())
             << "] Size: " << hexValue(Entry.second.getSize()) << "\n";
  });
}

Error LVBinaryReader::loadGenericTargetInfo(StringRef TheTriple,
                                            StringRef TheFeatures) {
  std::string TargetLookupError;
  const Target *TheTarget =
      TargetRegistry::lookupTarget(std::string(TheTriple), TargetLookupError);
  if (!TheTarget)
    return createStringError(errc::invalid_argument, TargetLookupError.c_str());

  // Register information.
  MCRegisterInfo *RegisterInfo = TheTarget->createMCRegInfo(TheTriple);
  if (!RegisterInfo)
    return createStringError(errc::invalid_argument,
                             "no register info for target " + TheTriple);
  MRI.reset(RegisterInfo);

  // Assembler properties and features.
  MCTargetOptions MCOptions;
  MCAsmInfo *AsmInfo(TheTarget->createMCAsmInfo(*MRI, TheTriple, MCOptions));
  if (!AsmInfo)
    return createStringError(errc::invalid_argument,
                             "no assembly info for target " + TheTriple);
  MAI.reset(AsmInfo);

  // Target subtargets.
  StringRef CPU;
  MCSubtargetInfo *SubtargetInfo(
      TheTarget->createMCSubtargetInfo(TheTriple, CPU, TheFeatures));
  if (!SubtargetInfo)
    return createStringError(errc::invalid_argument,
                             "no subtarget info for target " + TheTriple);
  STI.reset(SubtargetInfo);

  // Instructions Info.
  MCInstrInfo *InstructionInfo(TheTarget->createMCInstrInfo());
  if (!InstructionInfo)
    return createStringError(errc::invalid_argument,
                             "no instruction info for target " + TheTriple);
  MII.reset(InstructionInfo);

  MC = std::make_unique<MCContext>(Triple(TheTriple), MAI.get(), MRI.get(),
                                   STI.get());

  // Assembler.
  MCDisassembler *DisAsm(TheTarget->createMCDisassembler(*STI, *MC));
  if (!DisAsm)
    return createStringError(errc::invalid_argument,
                             "no disassembler for target " + TheTriple);
  MD.reset(DisAsm);

  MCInstPrinter *InstructionPrinter(TheTarget->createMCInstPrinter(
      Triple(TheTriple), AsmInfo->getAssemblerDialect(), *MAI, *MII, *MRI));
  if (!InstructionPrinter)
    return createStringError(errc::invalid_argument,
                             "no target assembly language printer for target " +
                                 TheTriple);
  MIP.reset(InstructionPrinter);
  InstructionPrinter->setPrintImmHex(true);

  return Error::success();
}

Expected<std::pair<uint64_t, object::SectionRef>>
LVBinaryReader::getSection(LVScope *Scope, LVAddress Address,
                           LVSectionIndex SectionIndex) {
  // Return the 'text' section with the code for this logical scope.
  // COFF: SectionIndex is zero. Use 'SectionAddresses' data.
  // ELF: SectionIndex is the section index in the file.
  if (SectionIndex) {
    LVSections::iterator Iter = Sections.find(SectionIndex);
    if (Iter == Sections.end()) {
      return createStringError(errc::invalid_argument,
                               "invalid section index for: '%s'",
                               Scope->getName().str().c_str());
    }
    const object::SectionRef Section = Iter->second;
    return std::make_pair(Section.getAddress(), Section);
  }

  // Ensure a valid starting address for the public names.
  LVSectionAddresses::const_iterator Iter =
      SectionAddresses.upper_bound(Address);
  if (Iter == SectionAddresses.begin())
    return createStringError(errc::invalid_argument,
                             "invalid section address for: '%s'",
                             Scope->getName().str().c_str());

  // Get section that contains the code for this function.
  Iter = SectionAddresses.lower_bound(Address);
  if (Iter != SectionAddresses.begin())
    --Iter;
  return std::make_pair(Iter->first, Iter->second);
}

void LVBinaryReader::addSectionRange(LVSectionIndex SectionIndex,
                                     LVScope *Scope) {
  LVRange *ScopesWithRanges = getSectionRanges(SectionIndex);
  ScopesWithRanges->addEntry(Scope);
}

void LVBinaryReader::addSectionRange(LVSectionIndex SectionIndex,
                                     LVScope *Scope, LVAddress LowerAddress,
                                     LVAddress UpperAddress) {
  LVRange *ScopesWithRanges = getSectionRanges(SectionIndex);
  ScopesWithRanges->addEntry(Scope, LowerAddress, UpperAddress);
}

LVRange *LVBinaryReader::getSectionRanges(LVSectionIndex SectionIndex) {
  LVRange *Range = nullptr;
  // Check if we already have a mapping for this section index.
  LVSectionRanges::iterator IterSection = SectionRanges.find(SectionIndex);
  if (IterSection == SectionRanges.end()) {
    Range = new LVRange();
    SectionRanges.emplace(SectionIndex, Range);
  } else {
    Range = IterSection->second;
  }
  assert(Range && "Range is null.");
  return Range;
}

LVBinaryReader::~LVBinaryReader() {
  // Delete the lines created by 'createInstructions'.
  std::vector<LVLines *> AllInstructionLines = ScopeInstructions.find();
  for (LVLines *Entry : AllInstructionLines)
    delete Entry;
  // Delete the ranges created by 'getSectionRanges'.
  for (LVSectionRanges::reference Entry : SectionRanges)
    delete Entry.second;
}

Error LVBinaryReader::createInstructions(LVScope *Scope,
                                         LVSectionIndex SectionIndex,
                                         const LVNameInfo &NameInfo) {
  assert(Scope && "Scope is null.");

  // Skip stripped functions.
  if (Scope->getIsDiscarded())
    return Error::success();

  // Find associated address and size for the given function entry point.
  LVAddress Address = NameInfo.first;
  uint64_t Size = NameInfo.second;

  LLVM_DEBUG({
    dbgs() << "\nPublic Name instructions: '" << Scope->getName() << "' / '"
           << Scope->getLinkageName() << "'\n"
           << "DIE Offset: " << hexValue(Scope->getOffset()) << " Range: ["
           << hexValue(Address) << ":" << hexValue(Address + Size) << "]\n";
  });

  Expected<std::pair<uint64_t, const object::SectionRef>> SectionOrErr =
      getSection(Scope, Address, SectionIndex);
  if (!SectionOrErr)
    return SectionOrErr.takeError();
  const object::SectionRef Section = (*SectionOrErr).second;
  uint64_t SectionAddress = (*SectionOrErr).first;

  Expected<StringRef> SectionContentsOrErr = Section.getContents();
  if (!SectionContentsOrErr)
    return SectionOrErr.takeError();

  // There are cases where the section size is smaller than the [LowPC,HighPC]
  // range; it causes us to decode invalid addresses. The recorded size in the
  // logical scope is one less than the real size.
  LLVM_DEBUG({
    dbgs() << " Size: " << hexValue(Size)
           << ", Section Size: " << hexValue(Section.getSize()) << "\n";
  });
  Size = std::min(Size + 1, Section.getSize());

  ArrayRef<uint8_t> Bytes = arrayRefFromStringRef(*SectionContentsOrErr);
  uint64_t Offset = Address - SectionAddress;
  uint8_t const *Begin = Bytes.data() + Offset;
  uint8_t const *End = Bytes.data() + Offset + Size;

  LLVM_DEBUG({
    Expected<StringRef> SectionNameOrErr = Section.getName();
    if (!SectionNameOrErr)
      consumeError(SectionNameOrErr.takeError());
    else
      dbgs() << "Section Index: " << hexValue(Section.getIndex()) << " ["
             << hexValue((uint64_t)Section.getAddress()) << ":"
             << hexValue((uint64_t)Section.getAddress() + Section.getSize(), 10)
             << "] Name: '" << *SectionNameOrErr << "'\n"
             << "Begin: " << hexValue((uint64_t)Begin)
             << ", End: " << hexValue((uint64_t)End) << "\n";
  });

  // Address for first instruction line.
  LVAddress FirstAddress = Address;
  LVLines *Instructions = new LVLines();

  while (Begin < End) {
    MCInst Instruction;
    uint64_t BytesConsumed = 0;
    SmallVector<char, 64> InsnStr;
    raw_svector_ostream Annotations(InsnStr);
    MCDisassembler::DecodeStatus const S =
        MD->getInstruction(Instruction, BytesConsumed,
                           ArrayRef<uint8_t>(Begin, End), Address, outs());
    switch (S) {
    case MCDisassembler::Fail:
      LLVM_DEBUG({ dbgs() << "Invalid instruction\n"; });
      if (BytesConsumed == 0)
        // Skip invalid bytes
        BytesConsumed = 1;
      break;
    case MCDisassembler::SoftFail:
      LLVM_DEBUG({ dbgs() << "Potentially undefined instruction:"; });
      LLVM_FALLTHROUGH;
    case MCDisassembler::Success: {
      std::string Buffer;
      raw_string_ostream Stream(Buffer);
      StringRef AnnotationsStr = Annotations.str();
      MIP->printInst(&Instruction, Address, AnnotationsStr, *STI, Stream);
      LLVM_DEBUG({
        std::string BufferCodes;
        raw_string_ostream StreamCodes(BufferCodes);
        StreamCodes << format_bytes(
            ArrayRef<uint8_t>(Begin, Begin + BytesConsumed), std::nullopt, 16,
            16);
        dbgs() << "[" << hexValue((uint64_t)Begin) << "] "
               << "Size: " << format_decimal(BytesConsumed, 2) << " ("
               << formatv("{0}",
                          fmt_align(StreamCodes.str(), AlignStyle::Left, 32))
               << ") " << hexValue((uint64_t)Address) << ": " << Stream.str()
               << "\n";
      });
      // Here we add logical lines to the Instructions. Later on,
      // the 'processLines()' function will move each created logical line
      // to its enclosing logical scope, using the debug ranges information
      // and they will be released when its scope parent is deleted.
      LVLineAssembler *Line = new LVLineAssembler();
      Line->setAddress(Address);
      Line->setName(StringRef(Stream.str()).trim());
      Instructions->push_back(Line);
      break;
    }
    }
    Address += BytesConsumed;
    Begin += BytesConsumed;
  }

  LLVM_DEBUG({
    size_t Index = 0;
    dbgs() << "\nSectionIndex: " << format_decimal(SectionIndex, 3)
           << " Scope DIE: " << hexValue(Scope->getOffset()) << "\n"
           << "Address: " << hexValue(FirstAddress)
           << format(" - Collected instructions lines: %d\n",
                     Instructions->size());
    for (const LVLine *Line : *Instructions)
      dbgs() << format_decimal(++Index, 5) << ": "
             << hexValue(Line->getOffset()) << ", (" << Line->getName()
             << ")\n";
  });

  // The scope in the assembler names is linked to its own instructions.
  ScopeInstructions.add(SectionIndex, Scope, Instructions);
  AssemblerMappings.add(SectionIndex, FirstAddress, Scope);

  return Error::success();
}

Error LVBinaryReader::createInstructions(LVScope *Function,
                                         LVSectionIndex SectionIndex) {
  if (!options().getPrintInstructions())
    return Error::success();

  LVNameInfo Name = CompileUnit->findPublicName(Function);
  if (Name.first != LVAddress(UINT64_MAX))
    return createInstructions(Function, SectionIndex, Name);

  return Error::success();
}

Error LVBinaryReader::createInstructions() {
  if (!options().getPrintInstructions())
    return Error::success();

  LLVM_DEBUG({
    size_t Index = 1;
    dbgs() << "\nPublic Names (Scope):\n";
    for (LVPublicNames::const_reference Name : CompileUnit->getPublicNames()) {
      LVScope *Scope = Name.first;
      const LVNameInfo &NameInfo = Name.second;
      LVAddress Address = NameInfo.first;
      uint64_t Size = NameInfo.second;
      dbgs() << format_decimal(Index++, 5) << ": "
             << "DIE Offset: " << hexValue(Scope->getOffset()) << " Range: ["
             << hexValue(Address) << ":" << hexValue(Address + Size) << "] "
             << "Name: '" << Scope->getName() << "' / '"
             << Scope->getLinkageName() << "'\n";
    }
  });

  // For each public name in the current compile unit, create the line
  // records that represent the executable instructions.
  for (LVPublicNames::const_reference Name : CompileUnit->getPublicNames()) {
    LVScope *Scope = Name.first;
    // The symbol table extracted from the object file always contains a
    // non-empty name (linkage name). However, the logical scope does not
    // guarantee to have a name for the linkage name (main is one case).
    // For those cases, set the linkage name the same as the name.
    if (!Scope->getLinkageNameIndex())
      Scope->setLinkageName(Scope->getName());
    LVSectionIndex SectionIndex = getSymbolTableIndex(Scope->getLinkageName());
    if (Error Err = createInstructions(Scope, SectionIndex, Name.second))
      return Err;
  }

  return Error::success();
}

// During the traversal of the debug information sections, we created the
// logical lines representing the disassembled instructions from the text
// section and the logical lines representing the line records from the
// debug line section. Using the ranges associated with the logical scopes,
// we will allocate those logical lines to their logical scopes.
void LVBinaryReader::processLines(LVLines *DebugLines,
                                  LVSectionIndex SectionIndex,
                                  LVScope *Function) {
  assert(DebugLines && "DebugLines is null.");

  // Just return if this compilation unit does not have any line records
  // and no instruction lines were created.
  if (DebugLines->empty() && !options().getPrintInstructions())
    return;

  // Merge the debug lines and instruction lines using their text address;
  // the logical line representing the debug line record is followed by the
  // line(s) representing the disassembled instructions, whose addresses are
  // equal or greater that the line address and less than the address of the
  // next debug line record.
  LLVM_DEBUG({
    size_t Index = 1;
    size_t PerLine = 4;
    dbgs() << format("\nProcess debug lines: %d\n", DebugLines->size());
    for (const LVLine *Line : *DebugLines) {
      dbgs() << format_decimal(Index, 5) << ": " << hexValue(Line->getOffset())
             << ", (" << Line->getLineNumber() << ")"
             << ((Index % PerLine) ? "  " : "\n");
      ++Index;
    }
    dbgs() << ((Index % PerLine) ? "\n" : "");
  });

  bool TraverseLines = true;
  LVLines::iterator Iter = DebugLines->begin();
  while (TraverseLines && Iter != DebugLines->end()) {
    uint64_t DebugAddress = (*Iter)->getAddress();

    // Get the function with an entry point that matches this line and
    // its associated assembler entries. In the case of COMDAT, the input
    // 'Function' is not null. Use it to find its address ranges.
    LVScope *Scope = Function;
    if (!Function) {
      Scope = AssemblerMappings.find(SectionIndex, DebugAddress);
      if (!Scope) {
        ++Iter;
        continue;
      }
    }

    // Get the associated instructions for the found 'Scope'.
    LVLines InstructionLines;
    LVLines *Lines = ScopeInstructions.find(SectionIndex, Scope);
    if (Lines)
      InstructionLines = std::move(*Lines);

    LLVM_DEBUG({
      size_t Index = 0;
      dbgs() << "\nSectionIndex: " << format_decimal(SectionIndex, 3)
             << " Scope DIE: " << hexValue(Scope->getOffset()) << "\n"
             << format("Process instruction lines: %d\n",
                       InstructionLines.size());
      for (const LVLine *Line : InstructionLines)
        dbgs() << format_decimal(++Index, 5) << ": "
               << hexValue(Line->getOffset()) << ", (" << Line->getName()
               << ")\n";
    });

    // Continue with next debug line if there are not instructions lines.
    if (InstructionLines.empty()) {
      ++Iter;
      continue;
    }

    for (LVLine *InstructionLine : InstructionLines) {
      uint64_t InstructionAddress = InstructionLine->getAddress();
      LLVM_DEBUG({
        dbgs() << "Instruction address: " << hexValue(InstructionAddress)
               << "\n";
      });
      if (TraverseLines) {
        while (Iter != DebugLines->end()) {
          DebugAddress = (*Iter)->getAddress();
          LLVM_DEBUG({
            bool IsDebug = (*Iter)->getIsLineDebug();
            dbgs() << "Line " << (IsDebug ? "dbg:" : "ins:") << " ["
                   << hexValue(DebugAddress) << "]";
            if (IsDebug)
              dbgs() << format(" %d", (*Iter)->getLineNumber());
            dbgs() << "\n";
          });
          // Instruction address before debug line.
          if (InstructionAddress < DebugAddress) {
            LLVM_DEBUG({
              dbgs() << "Inserted instruction address: "
                     << hexValue(InstructionAddress) << " before line: "
                     << format("%d", (*Iter)->getLineNumber()) << " ["
                     << hexValue(DebugAddress) << "]\n";
            });
            Iter = DebugLines->insert(Iter, InstructionLine);
            // The returned iterator points to the inserted instruction.
            // Skip it and point to the line acting as reference.
            ++Iter;
            break;
          }
          ++Iter;
        }
        if (Iter == DebugLines->end()) {
          // We have reached the end of the source lines and the current
          // instruction line address is greater than the last source line.
          TraverseLines = false;
          DebugLines->push_back(InstructionLine);
        }
      } else {
        DebugLines->push_back(InstructionLine);
      }
    }
  }

  LLVM_DEBUG({
    dbgs() << format("Lines after merge: %d\n", DebugLines->size());
    size_t Index = 0;
    for (const LVLine *Line : *DebugLines) {
      dbgs() << format_decimal(++Index, 5) << ": "
             << hexValue(Line->getOffset()) << ", ("
             << ((Line->getIsLineDebug())
                     ? Line->lineNumberAsStringStripped(/*ShowZero=*/true)
                     : Line->getName())
             << ")\n";
    }
  });

  // If this compilation unit does not have line records, traverse its scopes
  // and take any collected instruction lines as the working set in order
  // to move them to their associated scope.
  if (DebugLines->empty()) {
    if (const LVScopes *Scopes = CompileUnit->getScopes())
      for (LVScope *Scope : *Scopes) {
        LVLines *Lines = ScopeInstructions.find(Scope);
        if (Lines) {

          LLVM_DEBUG({
            size_t Index = 0;
            dbgs() << "\nSectionIndex: " << format_decimal(SectionIndex, 3)
                   << " Scope DIE: " << hexValue(Scope->getOffset()) << "\n"
                   << format("Instruction lines: %d\n", Lines->size());
            for (const LVLine *Line : *Lines)
              dbgs() << format_decimal(++Index, 5) << ": "
                     << hexValue(Line->getOffset()) << ", (" << Line->getName()
                     << ")\n";
          });

          if (Scope->getIsArtificial()) {
            // Add the instruction lines to their artificial scope.
            for (LVLine *Line : *Lines)
              Scope->addElement(Line);
          } else {
            DebugLines->append(*Lines);
          }
          Lines->clear();
        }
      }
  }

  LVRange *ScopesWithRanges = getSectionRanges(SectionIndex);
  ScopesWithRanges->startSearch();

  // Process collected lines.
  LVScope *Scope;
  for (LVLine *Line : *DebugLines) {
    // Using the current line address, get its associated lexical scope and
    // add the line information to it.
    Scope = ScopesWithRanges->getEntry(Line->getAddress());
    if (!Scope) {
      // If missing scope, use the compile unit.
      Scope = CompileUnit;
      LLVM_DEBUG({
        dbgs() << "Adding line to CU: " << hexValue(Line->getOffset()) << ", ("
               << ((Line->getIsLineDebug())
                       ? Line->lineNumberAsStringStripped(/*ShowZero=*/true)
                       : Line->getName())
               << ")\n";
      });
    }

    // Add line object to scope.
    Scope->addElement(Line);

    // Report any line zero.
    if (options().getWarningLines() && Line->getIsLineDebug() &&
        !Line->getLineNumber())
      CompileUnit->addLineZero(Line);

    // Some compilers generate ranges in the compile unit; other compilers
    // only DW_AT_low_pc/DW_AT_high_pc. In order to correctly map global
    // variables, we need to generate the map ranges for the compile unit.
    // If we use the ranges stored at the scope level, there are cases where
    // the address referenced by a symbol location, is not in the enclosing
    // scope, but in an outer one. By using the ranges stored in the compile
    // unit, we can catch all those addresses.
    if (Line->getIsLineDebug())
      CompileUnit->addMapping(Line, SectionIndex);

    // Resolve any given pattern.
    patterns().resolvePatternMatch(Line);
  }

  ScopesWithRanges->endSearch();
}

void LVBinaryReader::processLines(LVLines *DebugLines,
                                  LVSectionIndex SectionIndex) {
  assert(DebugLines && "DebugLines is null.");
  if (DebugLines->empty() && !ScopeInstructions.findMap(SectionIndex))
    return;

  // If the Compile Unit does not contain comdat functions, use the whole
  // set of debug lines, as the addresses don't have conflicts.
  if (!CompileUnit->getHasComdatScopes()) {
    processLines(DebugLines, SectionIndex, nullptr);
    return;
  }

  // Find the indexes for the lines whose address is zero.
  std::vector<size_t> AddressZero;
  LVLines::iterator It =
      std::find_if(std::begin(*DebugLines), std::end(*DebugLines),
                   [](LVLine *Line) { return !Line->getAddress(); });
  while (It != std::end(*DebugLines)) {
    AddressZero.emplace_back(std::distance(std::begin(*DebugLines), It));
    It = std::find_if(std::next(It), std::end(*DebugLines),
                      [](LVLine *Line) { return !Line->getAddress(); });
  }

  // If the set of debug lines does not contain any line with address zero,
  // use the whole set. It means we are dealing with an initialization
  // section from a fully linked binary.
  if (AddressZero.empty()) {
    processLines(DebugLines, SectionIndex, nullptr);
    return;
  }

  // The Compile unit contains comdat functions. Traverse the collected
  // debug lines and identify logical groups based on their start and
  // address. Each group starts with a zero address.
  // Begin, End, Address, IsDone.
  using LVBucket = std::tuple<size_t, size_t, LVAddress, bool>;
  std::vector<LVBucket> Buckets;

  LVAddress Address;
  size_t Begin = 0;
  size_t End = 0;
  size_t Index = 0;
  for (Index = 0; Index < AddressZero.size() - 1; ++Index) {
    Begin = AddressZero[Index];
    End = AddressZero[Index + 1] - 1;
    Address = (*DebugLines)[End]->getAddress();
    Buckets.emplace_back(Begin, End, Address, false);
  }

  // Add the last bucket.
  if (Index) {
    Begin = AddressZero[Index];
    End = DebugLines->size() - 1;
    Address = (*DebugLines)[End]->getAddress();
    Buckets.emplace_back(Begin, End, Address, false);
  }

  LLVM_DEBUG({
    dbgs() << "\nDebug Lines buckets: " << Buckets.size() << "\n";
    for (LVBucket &Bucket : Buckets) {
      dbgs() << "Begin: " << format_decimal(std::get<0>(Bucket), 5) << ", "
             << "End: " << format_decimal(std::get<1>(Bucket), 5) << ", "
             << "Address: " << hexValue(std::get<2>(Bucket)) << "\n";
    }
  });

  // Traverse the sections and buckets looking for matches on the section
  // sizes. In the unlikely event of different buckets with the same size
  // process them in order and mark them as done.
  LVLines Group;
  for (LVSections::reference Entry : Sections) {
    LVSectionIndex SectionIndex = Entry.first;
    const object::SectionRef Section = Entry.second;
    uint64_t Size = Section.getSize();
    LLVM_DEBUG({
      dbgs() << "\nSection Index: " << format_decimal(SectionIndex, 3)
             << " , Section Size: " << hexValue(Section.getSize())
             << " , Section Address: " << hexValue(Section.getAddress())
             << "\n";
    });

    for (LVBucket &Bucket : Buckets) {
      if (std::get<3>(Bucket))
        // Already done for previous section.
        continue;
      if (Size == std::get<2>(Bucket)) {
        // We have a match on the section size.
        Group.clear();
        LVLines::iterator IterStart = DebugLines->begin() + std::get<0>(Bucket);
        LVLines::iterator IterEnd =
            DebugLines->begin() + std::get<1>(Bucket) + 1;
        for (LVLines::iterator Iter = IterStart; Iter < IterEnd; ++Iter)
          Group.push_back(*Iter);
        processLines(&Group, SectionIndex, /*Function=*/nullptr);
        std::get<3>(Bucket) = true;
        break;
      }
    }
  }
}

void LVBinaryReader::print(raw_ostream &OS) const {
  OS << "LVBinaryReader\n";
  LLVM_DEBUG(dbgs() << "PrintReader\n");
}