aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm16/include/llvm/DebugInfo/DWARF/DWARFUnit.h
blob: ea584c724f193ae0ce3cc824ba742f96080f3bae (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
#pragma once

#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif

//===- DWARFUnit.h ----------------------------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_DEBUGINFO_DWARF_DWARFUNIT_H
#define LLVM_DEBUGINFO_DWARF_DWARFUNIT_H

#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
#include "llvm/DebugInfo/DWARF/DWARFDie.h"
#include "llvm/DebugInfo/DWARF/DWARFLocationExpression.h"
#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
#include "llvm/Support/DataExtractor.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <map>
#include <memory>
#include <set>
#include <utility>
#include <vector>

namespace llvm {

class DWARFAbbreviationDeclarationSet;
class DWARFContext;
class DWARFDebugAbbrev;
class DWARFUnit;
class DWARFDebugRangeList;
class DWARFLocationTable;
class DWARFObject;
class raw_ostream;
struct DIDumpOptions;
struct DWARFSection;

/// Base class describing the header of any kind of "unit."  Some information
/// is specific to certain unit types.  We separate this class out so we can
/// parse the header before deciding what specific kind of unit to construct.
class DWARFUnitHeader {
  // Offset within section.
  uint64_t Offset = 0;
  // Version, address size, and DWARF format.
  dwarf::FormParams FormParams;
  uint64_t Length = 0;
  uint64_t AbbrOffset = 0;

  // For DWO units only.
  const DWARFUnitIndex::Entry *IndexEntry = nullptr;

  // For type units only.
  uint64_t TypeHash = 0;
  uint64_t TypeOffset = 0;

  // For v5 split or skeleton compile units only.
  std::optional<uint64_t> DWOId;

  // Unit type as parsed, or derived from the section kind.
  uint8_t UnitType = 0;

  // Size as parsed. uint8_t for compactness.
  uint8_t Size = 0;

public:
  /// Parse a unit header from \p debug_info starting at \p offset_ptr.
  /// Note that \p SectionKind is used as a hint to guess the unit type
  /// for DWARF formats prior to DWARFv5. In DWARFv5 the unit type is
  /// explicitly defined in the header and the hint is ignored.
  bool extract(DWARFContext &Context, const DWARFDataExtractor &debug_info,
               uint64_t *offset_ptr, DWARFSectionKind SectionKind);
  // For units in DWARF Package File, remember the index entry and update
  // the abbreviation offset read by extract().
  bool applyIndexEntry(const DWARFUnitIndex::Entry *Entry);
  uint64_t getOffset() const { return Offset; }
  const dwarf::FormParams &getFormParams() const { return FormParams; }
  uint16_t getVersion() const { return FormParams.Version; }
  dwarf::DwarfFormat getFormat() const { return FormParams.Format; }
  uint8_t getAddressByteSize() const { return FormParams.AddrSize; }
  uint8_t getRefAddrByteSize() const { return FormParams.getRefAddrByteSize(); }
  uint8_t getDwarfOffsetByteSize() const {
    return FormParams.getDwarfOffsetByteSize();
  }
  uint64_t getLength() const { return Length; }
  uint64_t getAbbrOffset() const { return AbbrOffset; }
  std::optional<uint64_t> getDWOId() const { return DWOId; }
  void setDWOId(uint64_t Id) {
    assert((!DWOId || *DWOId == Id) && "setting DWOId to a different value");
    DWOId = Id;
  }
  const DWARFUnitIndex::Entry *getIndexEntry() const { return IndexEntry; }
  uint64_t getTypeHash() const { return TypeHash; }
  uint64_t getTypeOffset() const { return TypeOffset; }
  uint8_t getUnitType() const { return UnitType; }
  bool isTypeUnit() const {
    return UnitType == dwarf::DW_UT_type || UnitType == dwarf::DW_UT_split_type;
  }
  uint8_t getSize() const { return Size; }
  uint8_t getUnitLengthFieldByteSize() const {
    return dwarf::getUnitLengthFieldByteSize(FormParams.Format);
  }
  uint64_t getNextUnitOffset() const {
    return Offset + Length + getUnitLengthFieldByteSize();
  }
};

const DWARFUnitIndex &getDWARFUnitIndex(DWARFContext &Context,
                                        DWARFSectionKind Kind);

bool isCompileUnit(const std::unique_ptr<DWARFUnit> &U);

/// Describe a collection of units. Intended to hold all units either from
/// .debug_info and .debug_types, or from .debug_info.dwo and .debug_types.dwo.
class DWARFUnitVector final : public SmallVector<std::unique_ptr<DWARFUnit>, 1> {
  std::function<std::unique_ptr<DWARFUnit>(uint64_t, DWARFSectionKind,
                                           const DWARFSection *,
                                           const DWARFUnitIndex::Entry *)>
      Parser;
  int NumInfoUnits = -1;

public:
  using UnitVector = SmallVectorImpl<std::unique_ptr<DWARFUnit>>;
  using iterator = typename UnitVector::iterator;
  using iterator_range = llvm::iterator_range<typename UnitVector::iterator>;

  using compile_unit_range =
      decltype(make_filter_range(std::declval<iterator_range>(), isCompileUnit));

  DWARFUnit *getUnitForOffset(uint64_t Offset) const;
  DWARFUnit *getUnitForIndexEntry(const DWARFUnitIndex::Entry &E);

  /// Read units from a .debug_info or .debug_types section.  Calls made
  /// before finishedInfoUnits() are assumed to be for .debug_info sections,
  /// calls after finishedInfoUnits() are for .debug_types sections.  Caller
  /// must not mix calls to addUnitsForSection and addUnitsForDWOSection.
  void addUnitsForSection(DWARFContext &C, const DWARFSection &Section,
                          DWARFSectionKind SectionKind);
  /// Read units from a .debug_info.dwo or .debug_types.dwo section.  Calls
  /// made before finishedInfoUnits() are assumed to be for .debug_info.dwo
  /// sections, calls after finishedInfoUnits() are for .debug_types.dwo
  /// sections.  Caller must not mix calls to addUnitsForSection and
  /// addUnitsForDWOSection.
  void addUnitsForDWOSection(DWARFContext &C, const DWARFSection &DWOSection,
                             DWARFSectionKind SectionKind, bool Lazy = false);

  /// Add an existing DWARFUnit to this UnitVector. This is used by the DWARF
  /// verifier to process unit separately.
  DWARFUnit *addUnit(std::unique_ptr<DWARFUnit> Unit);

  /// Returns number of all units held by this instance.
  unsigned getNumUnits() const { return size(); }
  /// Returns number of units from all .debug_info[.dwo] sections.
  unsigned getNumInfoUnits() const {
    return NumInfoUnits == -1 ? size() : NumInfoUnits;
  }
  /// Returns number of units from all .debug_types[.dwo] sections.
  unsigned getNumTypesUnits() const { return size() - NumInfoUnits; }
  /// Indicate that parsing .debug_info[.dwo] is done, and remaining units
  /// will be from .debug_types[.dwo].
  void finishedInfoUnits() { NumInfoUnits = size(); }

private:
  void addUnitsImpl(DWARFContext &Context, const DWARFObject &Obj,
                    const DWARFSection &Section, const DWARFDebugAbbrev *DA,
                    const DWARFSection *RS, const DWARFSection *LocSection,
                    StringRef SS, const DWARFSection &SOS,
                    const DWARFSection *AOS, const DWARFSection &LS, bool LE,
                    bool IsDWO, bool Lazy, DWARFSectionKind SectionKind);
};

/// Represents base address of the CU.
/// Represents a unit's contribution to the string offsets table.
struct StrOffsetsContributionDescriptor {
  uint64_t Base = 0;
  /// The contribution size not including the header.
  uint64_t Size = 0;
  /// Format and version.
  dwarf::FormParams FormParams = {0, 0, dwarf::DwarfFormat::DWARF32};

  StrOffsetsContributionDescriptor(uint64_t Base, uint64_t Size,
                                   uint8_t Version, dwarf::DwarfFormat Format)
      : Base(Base), Size(Size), FormParams({Version, 0, Format}) {}
  StrOffsetsContributionDescriptor() = default;

  uint8_t getVersion() const { return FormParams.Version; }
  dwarf::DwarfFormat getFormat() const { return FormParams.Format; }
  uint8_t getDwarfOffsetByteSize() const {
    return FormParams.getDwarfOffsetByteSize();
  }
  /// Determine whether a contribution to the string offsets table is
  /// consistent with the relevant section size and that its length is
  /// a multiple of the size of one of its entries.
  Expected<StrOffsetsContributionDescriptor>
  validateContributionSize(DWARFDataExtractor &DA);
};

class DWARFUnit {
  DWARFContext &Context;
  /// Section containing this DWARFUnit.
  const DWARFSection &InfoSection;

  DWARFUnitHeader Header;
  const DWARFDebugAbbrev *Abbrev;
  const DWARFSection *RangeSection;
  uint64_t RangeSectionBase;
  uint64_t LocSectionBase;

  /// Location table of this unit.
  std::unique_ptr<DWARFLocationTable> LocTable;

  const DWARFSection &LineSection;
  StringRef StringSection;
  const DWARFSection &StringOffsetSection;
  const DWARFSection *AddrOffsetSection;
  DWARFUnit *SU;
  std::optional<uint64_t> AddrOffsetSectionBase;
  bool IsLittleEndian;
  bool IsDWO;
  const DWARFUnitVector &UnitVector;

  /// Start, length, and DWARF format of the unit's contribution to the string
  /// offsets table (DWARF v5).
  std::optional<StrOffsetsContributionDescriptor>
      StringOffsetsTableContribution;

  mutable const DWARFAbbreviationDeclarationSet *Abbrevs;
  std::optional<object::SectionedAddress> BaseAddr;
  /// The compile unit debug information entry items.
  std::vector<DWARFDebugInfoEntry> DieArray;

  /// Map from range's start address to end address and corresponding DIE.
  /// IntervalMap does not support range removal, as a result, we use the
  /// std::map::upper_bound for address range lookup.
  std::map<uint64_t, std::pair<uint64_t, DWARFDie>> AddrDieMap;

  /// Map from the location (interpreted DW_AT_location) of a DW_TAG_variable,
  /// to the end address and the corresponding DIE.
  std::map<uint64_t, std::pair<uint64_t, DWARFDie>> VariableDieMap;
  DenseSet<uint64_t> RootsParsedForVariables;

  using die_iterator_range =
      iterator_range<std::vector<DWARFDebugInfoEntry>::iterator>;

  std::shared_ptr<DWARFUnit> DWO;

protected:
  /// Return the index of a \p Die entry inside the unit's DIE vector.
  ///
  /// It is illegal to call this method with a DIE that hasn't be
  /// created by this unit. In other word, it's illegal to call this
  /// method on a DIE that isn't accessible by following
  /// children/sibling links starting from this unit's getUnitDIE().
  uint32_t getDIEIndex(const DWARFDebugInfoEntry *Die) const {
    auto First = DieArray.data();
    assert(Die >= First && Die < First + DieArray.size());
    return Die - First;
  }

  /// Return DWARFDebugInfoEntry for the specified index \p Index.
  const DWARFDebugInfoEntry *getDebugInfoEntry(unsigned Index) const {
    assert(Index < DieArray.size());
    return &DieArray[Index];
  }

  const DWARFDebugInfoEntry *
  getParentEntry(const DWARFDebugInfoEntry *Die) const;
  const DWARFDebugInfoEntry *
  getSiblingEntry(const DWARFDebugInfoEntry *Die) const;
  const DWARFDebugInfoEntry *
  getPreviousSiblingEntry(const DWARFDebugInfoEntry *Die) const;
  const DWARFDebugInfoEntry *
  getFirstChildEntry(const DWARFDebugInfoEntry *Die) const;
  const DWARFDebugInfoEntry *
  getLastChildEntry(const DWARFDebugInfoEntry *Die) const;

  const DWARFUnitHeader &getHeader() const { return Header; }

  /// Find the unit's contribution to the string offsets table and determine its
  /// length and form. The given offset is expected to be derived from the unit
  /// DIE's DW_AT_str_offsets_base attribute.
  Expected<std::optional<StrOffsetsContributionDescriptor>>
  determineStringOffsetsTableContribution(DWARFDataExtractor &DA);

  /// Find the unit's contribution to the string offsets table and determine its
  /// length and form. The given offset is expected to be 0 in a dwo file or,
  /// in a dwp file, the start of the unit's contribution to the string offsets
  /// table section (as determined by the index table).
  Expected<std::optional<StrOffsetsContributionDescriptor>>
  determineStringOffsetsTableContributionDWO(DWARFDataExtractor &DA);

public:
  DWARFUnit(DWARFContext &Context, const DWARFSection &Section,
            const DWARFUnitHeader &Header, const DWARFDebugAbbrev *DA,
            const DWARFSection *RS, const DWARFSection *LocSection,
            StringRef SS, const DWARFSection &SOS, const DWARFSection *AOS,
            const DWARFSection &LS, bool LE, bool IsDWO,
            const DWARFUnitVector &UnitVector);

  virtual ~DWARFUnit();

  bool isLittleEndian() const { return IsLittleEndian; }
  bool isDWOUnit() const { return IsDWO; }
  DWARFContext& getContext() const { return Context; }
  const DWARFSection &getInfoSection() const { return InfoSection; }
  uint64_t getOffset() const { return Header.getOffset(); }
  const dwarf::FormParams &getFormParams() const {
    return Header.getFormParams();
  }
  uint16_t getVersion() const { return Header.getVersion(); }
  uint8_t getAddressByteSize() const { return Header.getAddressByteSize(); }
  uint8_t getRefAddrByteSize() const { return Header.getRefAddrByteSize(); }
  uint8_t getDwarfOffsetByteSize() const {
    return Header.getDwarfOffsetByteSize();
  }
  /// Size in bytes of the parsed unit header.
  uint32_t getHeaderSize() const { return Header.getSize(); }
  uint64_t getLength() const { return Header.getLength(); }
  dwarf::DwarfFormat getFormat() const { return Header.getFormat(); }
  uint8_t getUnitType() const { return Header.getUnitType(); }
  bool isTypeUnit() const { return Header.isTypeUnit(); }
  uint64_t getAbbrOffset() const { return Header.getAbbrOffset(); }
  uint64_t getNextUnitOffset() const { return Header.getNextUnitOffset(); }
  const DWARFSection &getLineSection() const { return LineSection; }
  StringRef getStringSection() const { return StringSection; }
  const DWARFSection &getStringOffsetSection() const {
    return StringOffsetSection;
  }

  void setSkeletonUnit(DWARFUnit *SU) { this->SU = SU; }
  // Returns itself if not using Split DWARF, or if the unit is a skeleton unit
  // - otherwise returns the split full unit's corresponding skeleton, if
  // available.
  DWARFUnit *getLinkedUnit() { return IsDWO ? SU : this; }

  void setAddrOffsetSection(const DWARFSection *AOS, uint64_t Base) {
    AddrOffsetSection = AOS;
    AddrOffsetSectionBase = Base;
  }

  std::optional<uint64_t> getAddrOffsetSectionBase() const {
    return AddrOffsetSectionBase;
  }

  /// Recursively update address to Die map.
  void updateAddressDieMap(DWARFDie Die);

  /// Recursively update address to variable Die map.
  void updateVariableDieMap(DWARFDie Die);

  void setRangesSection(const DWARFSection *RS, uint64_t Base) {
    RangeSection = RS;
    RangeSectionBase = Base;
  }

  uint64_t getLocSectionBase() const {
    return LocSectionBase;
  }

  std::optional<object::SectionedAddress>
  getAddrOffsetSectionItem(uint32_t Index) const;
  Expected<uint64_t> getStringOffsetSectionItem(uint32_t Index) const;

  DWARFDataExtractor getDebugInfoExtractor() const;

  DataExtractor getStringExtractor() const {
    return DataExtractor(StringSection, false, 0);
  }

  const DWARFLocationTable &getLocationTable() { return *LocTable; }

  /// Extract the range list referenced by this compile unit from the
  /// .debug_ranges section. If the extraction is unsuccessful, an error
  /// is returned. Successful extraction requires that the compile unit
  /// has already been extracted.
  Error extractRangeList(uint64_t RangeListOffset,
                         DWARFDebugRangeList &RangeList) const;
  void clear();

  const std::optional<StrOffsetsContributionDescriptor> &
  getStringOffsetsTableContribution() const {
    return StringOffsetsTableContribution;
  }

  uint8_t getDwarfStringOffsetsByteSize() const {
    assert(StringOffsetsTableContribution);
    return StringOffsetsTableContribution->getDwarfOffsetByteSize();
  }

  uint64_t getStringOffsetsBase() const {
    assert(StringOffsetsTableContribution);
    return StringOffsetsTableContribution->Base;
  }

  uint64_t getAbbreviationsOffset() const { return Header.getAbbrOffset(); }

  const DWARFAbbreviationDeclarationSet *getAbbreviations() const;

  static bool isMatchingUnitTypeAndTag(uint8_t UnitType, dwarf::Tag Tag) {
    switch (UnitType) {
    case dwarf::DW_UT_compile:
      return Tag == dwarf::DW_TAG_compile_unit;
    case dwarf::DW_UT_type:
      return Tag == dwarf::DW_TAG_type_unit;
    case dwarf::DW_UT_partial:
      return Tag == dwarf::DW_TAG_partial_unit;
    case dwarf::DW_UT_skeleton:
      return Tag == dwarf::DW_TAG_skeleton_unit;
    case dwarf::DW_UT_split_compile:
    case dwarf::DW_UT_split_type:
      return dwarf::isUnitType(Tag);
    }
    return false;
  }

  std::optional<object::SectionedAddress> getBaseAddress();

  DWARFDie getUnitDIE(bool ExtractUnitDIEOnly = true) {
    extractDIEsIfNeeded(ExtractUnitDIEOnly);
    if (DieArray.empty())
      return DWARFDie();
    return DWARFDie(this, &DieArray[0]);
  }

  DWARFDie getNonSkeletonUnitDIE(bool ExtractUnitDIEOnly = true,
                                 StringRef DWOAlternativeLocation = {}) {
    parseDWO(DWOAlternativeLocation);
    return DWO ? DWO->getUnitDIE(ExtractUnitDIEOnly)
               : getUnitDIE(ExtractUnitDIEOnly);
  }

  const char *getCompilationDir();
  std::optional<uint64_t> getDWOId() {
    extractDIEsIfNeeded(/*CUDieOnly*/ true);
    return getHeader().getDWOId();
  }
  void setDWOId(uint64_t NewID) { Header.setDWOId(NewID); }

  /// Return a vector of address ranges resulting from a (possibly encoded)
  /// range list starting at a given offset in the appropriate ranges section.
  Expected<DWARFAddressRangesVector> findRnglistFromOffset(uint64_t Offset);

  /// Return a vector of address ranges retrieved from an encoded range
  /// list whose offset is found via a table lookup given an index (DWARF v5
  /// and later).
  Expected<DWARFAddressRangesVector> findRnglistFromIndex(uint32_t Index);

  /// Return a rangelist's offset based on an index. The index designates
  /// an entry in the rangelist table's offset array and is supplied by
  /// DW_FORM_rnglistx.
  std::optional<uint64_t> getRnglistOffset(uint32_t Index);

  std::optional<uint64_t> getLoclistOffset(uint32_t Index);

  Expected<DWARFAddressRangesVector> collectAddressRanges();

  Expected<DWARFLocationExpressionsVector>
  findLoclistFromOffset(uint64_t Offset);

  /// Returns subprogram DIE with address range encompassing the provided
  /// address. The pointer is alive as long as parsed compile unit DIEs are not
  /// cleared.
  DWARFDie getSubroutineForAddress(uint64_t Address);

  /// Returns variable DIE for the address provided. The pointer is alive as
  /// long as parsed compile unit DIEs are not cleared.
  DWARFDie getVariableForAddress(uint64_t Address);

  /// getInlinedChainForAddress - fetches inlined chain for a given address.
  /// Returns empty chain if there is no subprogram containing address. The
  /// chain is valid as long as parsed compile unit DIEs are not cleared.
  void getInlinedChainForAddress(uint64_t Address,
                                 SmallVectorImpl<DWARFDie> &InlinedChain);

  /// Return the DWARFUnitVector containing this unit.
  const DWARFUnitVector &getUnitVector() const { return UnitVector; }

  /// Returns the number of DIEs in the unit. Parses the unit
  /// if necessary.
  unsigned getNumDIEs() {
    extractDIEsIfNeeded(false);
    return DieArray.size();
  }

  /// Return the index of a DIE inside the unit's DIE vector.
  ///
  /// It is illegal to call this method with a DIE that hasn't be
  /// created by this unit. In other word, it's illegal to call this
  /// method on a DIE that isn't accessible by following
  /// children/sibling links starting from this unit's getUnitDIE().
  uint32_t getDIEIndex(const DWARFDie &D) const {
    return getDIEIndex(D.getDebugInfoEntry());
  }

  /// Return the DIE object at the given index \p Index.
  DWARFDie getDIEAtIndex(unsigned Index) {
    return DWARFDie(this, getDebugInfoEntry(Index));
  }

  DWARFDie getParent(const DWARFDebugInfoEntry *Die);
  DWARFDie getSibling(const DWARFDebugInfoEntry *Die);
  DWARFDie getPreviousSibling(const DWARFDebugInfoEntry *Die);
  DWARFDie getFirstChild(const DWARFDebugInfoEntry *Die);
  DWARFDie getLastChild(const DWARFDebugInfoEntry *Die);

  /// Return the DIE object for a given offset \p Offset inside the
  /// unit's DIE vector.
  DWARFDie getDIEForOffset(uint64_t Offset) {
    if (std::optional<uint32_t> DieIdx = getDIEIndexForOffset(Offset))
      return DWARFDie(this, &DieArray[*DieIdx]);

    return DWARFDie();
  }

  /// Return the DIE index for a given offset \p Offset inside the
  /// unit's DIE vector.
  std::optional<uint32_t> getDIEIndexForOffset(uint64_t Offset) {
    extractDIEsIfNeeded(false);
    auto It =
        llvm::partition_point(DieArray, [=](const DWARFDebugInfoEntry &DIE) {
          return DIE.getOffset() < Offset;
        });
    if (It != DieArray.end() && It->getOffset() == Offset)
      return It - DieArray.begin();
    return std::nullopt;
  }

  uint32_t getLineTableOffset() const {
    if (auto IndexEntry = Header.getIndexEntry())
      if (const auto *Contrib = IndexEntry->getContribution(DW_SECT_LINE))
        return Contrib->getOffset32();
    return 0;
  }

  die_iterator_range dies() {
    extractDIEsIfNeeded(false);
    return die_iterator_range(DieArray.begin(), DieArray.end());
  }

  virtual void dump(raw_ostream &OS, DIDumpOptions DumpOpts) = 0;

  Error tryExtractDIEsIfNeeded(bool CUDieOnly);

private:
  /// Size in bytes of the .debug_info data associated with this compile unit.
  size_t getDebugInfoSize() const {
    return Header.getLength() + Header.getUnitLengthFieldByteSize() -
           getHeaderSize();
  }

  /// extractDIEsIfNeeded - Parses a compile unit and indexes its DIEs if it
  /// hasn't already been done
  void extractDIEsIfNeeded(bool CUDieOnly);

  /// extractDIEsToVector - Appends all parsed DIEs to a vector.
  void extractDIEsToVector(bool AppendCUDie, bool AppendNonCUDIEs,
                           std::vector<DWARFDebugInfoEntry> &DIEs) const;

  /// clearDIEs - Clear parsed DIEs to keep memory usage low.
  void clearDIEs(bool KeepCUDie);

  /// parseDWO - Parses .dwo file for current compile unit. Returns true if
  /// it was actually constructed.
  /// The \p AlternativeLocation specifies an alternative location to get
  /// the DWARF context for the DWO object; this is the case when it has
  /// been moved from its original location.
  bool parseDWO(StringRef AlternativeLocation = {});
};

inline bool isCompileUnit(const std::unique_ptr<DWARFUnit> &U) {
  return !U->isTypeUnit();
}

} // end namespace llvm

#endif // LLVM_DEBUGINFO_DWARF_DWARFUNIT_H

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif