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//===- DWARFUnit.h ----------------------------------------------*- C++ -*-===//
2
//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
5
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6
//
7
//===----------------------------------------------------------------------===//
8
 
9
#ifndef LLVM_DEBUGINFO_DWARF_DWARFUNIT_H
10
#define LLVM_DEBUGINFO_DWARF_DWARFUNIT_H
11
 
12
#include "llvm/ADT/DenseSet.h"
13
#include "llvm/ADT/STLExtras.h"
14
#include "llvm/ADT/SmallVector.h"
15
#include "llvm/ADT/StringRef.h"
16
#include "llvm/ADT/iterator_range.h"
17
#include "llvm/BinaryFormat/Dwarf.h"
18
#include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
19
#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
20
#include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
21
#include "llvm/DebugInfo/DWARF/DWARFDie.h"
22
#include "llvm/DebugInfo/DWARF/DWARFLocationExpression.h"
23
#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
24
#include "llvm/Support/DataExtractor.h"
25
#include <cassert>
26
#include <cstddef>
27
#include <cstdint>
28
#include <map>
29
#include <memory>
30
#include <set>
31
#include <utility>
32
#include <vector>
33
 
34
namespace llvm {
35
 
36
class DWARFAbbreviationDeclarationSet;
37
class DWARFContext;
38
class DWARFDebugAbbrev;
39
class DWARFUnit;
40
class DWARFDebugRangeList;
41
class DWARFLocationTable;
42
class DWARFObject;
43
class raw_ostream;
44
struct DIDumpOptions;
45
struct DWARFSection;
46
 
47
/// Base class describing the header of any kind of "unit."  Some information
48
/// is specific to certain unit types.  We separate this class out so we can
49
/// parse the header before deciding what specific kind of unit to construct.
50
class DWARFUnitHeader {
51
  // Offset within section.
52
  uint64_t Offset = 0;
53
  // Version, address size, and DWARF format.
54
  dwarf::FormParams FormParams;
55
  uint64_t Length = 0;
56
  uint64_t AbbrOffset = 0;
57
 
58
  // For DWO units only.
59
  const DWARFUnitIndex::Entry *IndexEntry = nullptr;
60
 
61
  // For type units only.
62
  uint64_t TypeHash = 0;
63
  uint64_t TypeOffset = 0;
64
 
65
  // For v5 split or skeleton compile units only.
66
  std::optional<uint64_t> DWOId;
67
 
68
  // Unit type as parsed, or derived from the section kind.
69
  uint8_t UnitType = 0;
70
 
71
  // Size as parsed. uint8_t for compactness.
72
  uint8_t Size = 0;
73
 
74
public:
75
  /// Parse a unit header from \p debug_info starting at \p offset_ptr.
76
  /// Note that \p SectionKind is used as a hint to guess the unit type
77
  /// for DWARF formats prior to DWARFv5. In DWARFv5 the unit type is
78
  /// explicitly defined in the header and the hint is ignored.
79
  bool extract(DWARFContext &Context, const DWARFDataExtractor &debug_info,
80
               uint64_t *offset_ptr, DWARFSectionKind SectionKind);
81
  // For units in DWARF Package File, remember the index entry and update
82
  // the abbreviation offset read by extract().
83
  bool applyIndexEntry(const DWARFUnitIndex::Entry *Entry);
84
  uint64_t getOffset() const { return Offset; }
85
  const dwarf::FormParams &getFormParams() const { return FormParams; }
86
  uint16_t getVersion() const { return FormParams.Version; }
87
  dwarf::DwarfFormat getFormat() const { return FormParams.Format; }
88
  uint8_t getAddressByteSize() const { return FormParams.AddrSize; }
89
  uint8_t getRefAddrByteSize() const { return FormParams.getRefAddrByteSize(); }
90
  uint8_t getDwarfOffsetByteSize() const {
91
    return FormParams.getDwarfOffsetByteSize();
92
  }
93
  uint64_t getLength() const { return Length; }
94
  uint64_t getAbbrOffset() const { return AbbrOffset; }
95
  std::optional<uint64_t> getDWOId() const { return DWOId; }
96
  void setDWOId(uint64_t Id) {
97
    assert((!DWOId || *DWOId == Id) && "setting DWOId to a different value");
98
    DWOId = Id;
99
  }
100
  const DWARFUnitIndex::Entry *getIndexEntry() const { return IndexEntry; }
101
  uint64_t getTypeHash() const { return TypeHash; }
102
  uint64_t getTypeOffset() const { return TypeOffset; }
103
  uint8_t getUnitType() const { return UnitType; }
104
  bool isTypeUnit() const {
105
    return UnitType == dwarf::DW_UT_type || UnitType == dwarf::DW_UT_split_type;
106
  }
107
  uint8_t getSize() const { return Size; }
108
  uint8_t getUnitLengthFieldByteSize() const {
109
    return dwarf::getUnitLengthFieldByteSize(FormParams.Format);
110
  }
111
  uint64_t getNextUnitOffset() const {
112
    return Offset + Length + getUnitLengthFieldByteSize();
113
  }
114
};
115
 
116
const DWARFUnitIndex &getDWARFUnitIndex(DWARFContext &Context,
117
                                        DWARFSectionKind Kind);
118
 
119
bool isCompileUnit(const std::unique_ptr<DWARFUnit> &U);
120
 
121
/// Describe a collection of units. Intended to hold all units either from
122
/// .debug_info and .debug_types, or from .debug_info.dwo and .debug_types.dwo.
123
class DWARFUnitVector final : public SmallVector<std::unique_ptr<DWARFUnit>, 1> {
124
  std::function<std::unique_ptr<DWARFUnit>(uint64_t, DWARFSectionKind,
125
                                           const DWARFSection *,
126
                                           const DWARFUnitIndex::Entry *)>
127
      Parser;
128
  int NumInfoUnits = -1;
129
 
130
public:
131
  using UnitVector = SmallVectorImpl<std::unique_ptr<DWARFUnit>>;
132
  using iterator = typename UnitVector::iterator;
133
  using iterator_range = llvm::iterator_range<typename UnitVector::iterator>;
134
 
135
  using compile_unit_range =
136
      decltype(make_filter_range(std::declval<iterator_range>(), isCompileUnit));
137
 
138
  DWARFUnit *getUnitForOffset(uint64_t Offset) const;
139
  DWARFUnit *getUnitForIndexEntry(const DWARFUnitIndex::Entry &E);
140
 
141
  /// Read units from a .debug_info or .debug_types section.  Calls made
142
  /// before finishedInfoUnits() are assumed to be for .debug_info sections,
143
  /// calls after finishedInfoUnits() are for .debug_types sections.  Caller
144
  /// must not mix calls to addUnitsForSection and addUnitsForDWOSection.
145
  void addUnitsForSection(DWARFContext &C, const DWARFSection &Section,
146
                          DWARFSectionKind SectionKind);
147
  /// Read units from a .debug_info.dwo or .debug_types.dwo section.  Calls
148
  /// made before finishedInfoUnits() are assumed to be for .debug_info.dwo
149
  /// sections, calls after finishedInfoUnits() are for .debug_types.dwo
150
  /// sections.  Caller must not mix calls to addUnitsForSection and
151
  /// addUnitsForDWOSection.
152
  void addUnitsForDWOSection(DWARFContext &C, const DWARFSection &DWOSection,
153
                             DWARFSectionKind SectionKind, bool Lazy = false);
154
 
155
  /// Add an existing DWARFUnit to this UnitVector. This is used by the DWARF
156
  /// verifier to process unit separately.
157
  DWARFUnit *addUnit(std::unique_ptr<DWARFUnit> Unit);
158
 
159
  /// Returns number of all units held by this instance.
160
  unsigned getNumUnits() const { return size(); }
161
  /// Returns number of units from all .debug_info[.dwo] sections.
162
  unsigned getNumInfoUnits() const {
163
    return NumInfoUnits == -1 ? size() : NumInfoUnits;
164
  }
165
  /// Returns number of units from all .debug_types[.dwo] sections.
166
  unsigned getNumTypesUnits() const { return size() - NumInfoUnits; }
167
  /// Indicate that parsing .debug_info[.dwo] is done, and remaining units
168
  /// will be from .debug_types[.dwo].
169
  void finishedInfoUnits() { NumInfoUnits = size(); }
170
 
171
private:
172
  void addUnitsImpl(DWARFContext &Context, const DWARFObject &Obj,
173
                    const DWARFSection &Section, const DWARFDebugAbbrev *DA,
174
                    const DWARFSection *RS, const DWARFSection *LocSection,
175
                    StringRef SS, const DWARFSection &SOS,
176
                    const DWARFSection *AOS, const DWARFSection &LS, bool LE,
177
                    bool IsDWO, bool Lazy, DWARFSectionKind SectionKind);
178
};
179
 
180
/// Represents base address of the CU.
181
/// Represents a unit's contribution to the string offsets table.
182
struct StrOffsetsContributionDescriptor {
183
  uint64_t Base = 0;
184
  /// The contribution size not including the header.
185
  uint64_t Size = 0;
186
  /// Format and version.
187
  dwarf::FormParams FormParams = {0, 0, dwarf::DwarfFormat::DWARF32};
188
 
189
  StrOffsetsContributionDescriptor(uint64_t Base, uint64_t Size,
190
                                   uint8_t Version, dwarf::DwarfFormat Format)
191
      : Base(Base), Size(Size), FormParams({Version, 0, Format}) {}
192
  StrOffsetsContributionDescriptor() = default;
193
 
194
  uint8_t getVersion() const { return FormParams.Version; }
195
  dwarf::DwarfFormat getFormat() const { return FormParams.Format; }
196
  uint8_t getDwarfOffsetByteSize() const {
197
    return FormParams.getDwarfOffsetByteSize();
198
  }
199
  /// Determine whether a contribution to the string offsets table is
200
  /// consistent with the relevant section size and that its length is
201
  /// a multiple of the size of one of its entries.
202
  Expected<StrOffsetsContributionDescriptor>
203
  validateContributionSize(DWARFDataExtractor &DA);
204
};
205
 
206
class DWARFUnit {
207
  DWARFContext &Context;
208
  /// Section containing this DWARFUnit.
209
  const DWARFSection &InfoSection;
210
 
211
  DWARFUnitHeader Header;
212
  const DWARFDebugAbbrev *Abbrev;
213
  const DWARFSection *RangeSection;
214
  uint64_t RangeSectionBase;
215
  uint64_t LocSectionBase;
216
 
217
  /// Location table of this unit.
218
  std::unique_ptr<DWARFLocationTable> LocTable;
219
 
220
  const DWARFSection &LineSection;
221
  StringRef StringSection;
222
  const DWARFSection &StringOffsetSection;
223
  const DWARFSection *AddrOffsetSection;
224
  DWARFUnit *SU;
225
  std::optional<uint64_t> AddrOffsetSectionBase;
226
  bool IsLittleEndian;
227
  bool IsDWO;
228
  const DWARFUnitVector &UnitVector;
229
 
230
  /// Start, length, and DWARF format of the unit's contribution to the string
231
  /// offsets table (DWARF v5).
232
  std::optional<StrOffsetsContributionDescriptor>
233
      StringOffsetsTableContribution;
234
 
235
  mutable const DWARFAbbreviationDeclarationSet *Abbrevs;
236
  std::optional<object::SectionedAddress> BaseAddr;
237
  /// The compile unit debug information entry items.
238
  std::vector<DWARFDebugInfoEntry> DieArray;
239
 
240
  /// Map from range's start address to end address and corresponding DIE.
241
  /// IntervalMap does not support range removal, as a result, we use the
242
  /// std::map::upper_bound for address range lookup.
243
  std::map<uint64_t, std::pair<uint64_t, DWARFDie>> AddrDieMap;
244
 
245
  /// Map from the location (interpreted DW_AT_location) of a DW_TAG_variable,
246
  /// to the end address and the corresponding DIE.
247
  std::map<uint64_t, std::pair<uint64_t, DWARFDie>> VariableDieMap;
248
  DenseSet<uint64_t> RootsParsedForVariables;
249
 
250
  using die_iterator_range =
251
      iterator_range<std::vector<DWARFDebugInfoEntry>::iterator>;
252
 
253
  std::shared_ptr<DWARFUnit> DWO;
254
 
255
protected:
256
  /// Return the index of a \p Die entry inside the unit's DIE vector.
257
  ///
258
  /// It is illegal to call this method with a DIE that hasn't be
259
  /// created by this unit. In other word, it's illegal to call this
260
  /// method on a DIE that isn't accessible by following
261
  /// children/sibling links starting from this unit's getUnitDIE().
262
  uint32_t getDIEIndex(const DWARFDebugInfoEntry *Die) const {
263
    auto First = DieArray.data();
264
    assert(Die >= First && Die < First + DieArray.size());
265
    return Die - First;
266
  }
267
 
268
  /// Return DWARFDebugInfoEntry for the specified index \p Index.
269
  const DWARFDebugInfoEntry *getDebugInfoEntry(unsigned Index) const {
270
    assert(Index < DieArray.size());
271
    return &DieArray[Index];
272
  }
273
 
274
  const DWARFDebugInfoEntry *
275
  getParentEntry(const DWARFDebugInfoEntry *Die) const;
276
  const DWARFDebugInfoEntry *
277
  getSiblingEntry(const DWARFDebugInfoEntry *Die) const;
278
  const DWARFDebugInfoEntry *
279
  getPreviousSiblingEntry(const DWARFDebugInfoEntry *Die) const;
280
  const DWARFDebugInfoEntry *
281
  getFirstChildEntry(const DWARFDebugInfoEntry *Die) const;
282
  const DWARFDebugInfoEntry *
283
  getLastChildEntry(const DWARFDebugInfoEntry *Die) const;
284
 
285
  const DWARFUnitHeader &getHeader() const { return Header; }
286
 
287
  /// Find the unit's contribution to the string offsets table and determine its
288
  /// length and form. The given offset is expected to be derived from the unit
289
  /// DIE's DW_AT_str_offsets_base attribute.
290
  Expected<std::optional<StrOffsetsContributionDescriptor>>
291
  determineStringOffsetsTableContribution(DWARFDataExtractor &DA);
292
 
293
  /// Find the unit's contribution to the string offsets table and determine its
294
  /// length and form. The given offset is expected to be 0 in a dwo file or,
295
  /// in a dwp file, the start of the unit's contribution to the string offsets
296
  /// table section (as determined by the index table).
297
  Expected<std::optional<StrOffsetsContributionDescriptor>>
298
  determineStringOffsetsTableContributionDWO(DWARFDataExtractor &DA);
299
 
300
public:
301
  DWARFUnit(DWARFContext &Context, const DWARFSection &Section,
302
            const DWARFUnitHeader &Header, const DWARFDebugAbbrev *DA,
303
            const DWARFSection *RS, const DWARFSection *LocSection,
304
            StringRef SS, const DWARFSection &SOS, const DWARFSection *AOS,
305
            const DWARFSection &LS, bool LE, bool IsDWO,
306
            const DWARFUnitVector &UnitVector);
307
 
308
  virtual ~DWARFUnit();
309
 
310
  bool isLittleEndian() const { return IsLittleEndian; }
311
  bool isDWOUnit() const { return IsDWO; }
312
  DWARFContext& getContext() const { return Context; }
313
  const DWARFSection &getInfoSection() const { return InfoSection; }
314
  uint64_t getOffset() const { return Header.getOffset(); }
315
  const dwarf::FormParams &getFormParams() const {
316
    return Header.getFormParams();
317
  }
318
  uint16_t getVersion() const { return Header.getVersion(); }
319
  uint8_t getAddressByteSize() const { return Header.getAddressByteSize(); }
320
  uint8_t getRefAddrByteSize() const { return Header.getRefAddrByteSize(); }
321
  uint8_t getDwarfOffsetByteSize() const {
322
    return Header.getDwarfOffsetByteSize();
323
  }
324
  /// Size in bytes of the parsed unit header.
325
  uint32_t getHeaderSize() const { return Header.getSize(); }
326
  uint64_t getLength() const { return Header.getLength(); }
327
  dwarf::DwarfFormat getFormat() const { return Header.getFormat(); }
328
  uint8_t getUnitType() const { return Header.getUnitType(); }
329
  bool isTypeUnit() const { return Header.isTypeUnit(); }
330
  uint64_t getAbbrOffset() const { return Header.getAbbrOffset(); }
331
  uint64_t getNextUnitOffset() const { return Header.getNextUnitOffset(); }
332
  const DWARFSection &getLineSection() const { return LineSection; }
333
  StringRef getStringSection() const { return StringSection; }
334
  const DWARFSection &getStringOffsetSection() const {
335
    return StringOffsetSection;
336
  }
337
 
338
  void setSkeletonUnit(DWARFUnit *SU) { this->SU = SU; }
339
  // Returns itself if not using Split DWARF, or if the unit is a skeleton unit
340
  // - otherwise returns the split full unit's corresponding skeleton, if
341
  // available.
342
  DWARFUnit *getLinkedUnit() { return IsDWO ? SU : this; }
343
 
344
  void setAddrOffsetSection(const DWARFSection *AOS, uint64_t Base) {
345
    AddrOffsetSection = AOS;
346
    AddrOffsetSectionBase = Base;
347
  }
348
 
349
  std::optional<uint64_t> getAddrOffsetSectionBase() const {
350
    return AddrOffsetSectionBase;
351
  }
352
 
353
  /// Recursively update address to Die map.
354
  void updateAddressDieMap(DWARFDie Die);
355
 
356
  /// Recursively update address to variable Die map.
357
  void updateVariableDieMap(DWARFDie Die);
358
 
359
  void setRangesSection(const DWARFSection *RS, uint64_t Base) {
360
    RangeSection = RS;
361
    RangeSectionBase = Base;
362
  }
363
 
364
  uint64_t getLocSectionBase() const {
365
    return LocSectionBase;
366
  }
367
 
368
  std::optional<object::SectionedAddress>
369
  getAddrOffsetSectionItem(uint32_t Index) const;
370
  Expected<uint64_t> getStringOffsetSectionItem(uint32_t Index) const;
371
 
372
  DWARFDataExtractor getDebugInfoExtractor() const;
373
 
374
  DataExtractor getStringExtractor() const {
375
    return DataExtractor(StringSection, false, 0);
376
  }
377
 
378
  const DWARFLocationTable &getLocationTable() { return *LocTable; }
379
 
380
  /// Extract the range list referenced by this compile unit from the
381
  /// .debug_ranges section. If the extraction is unsuccessful, an error
382
  /// is returned. Successful extraction requires that the compile unit
383
  /// has already been extracted.
384
  Error extractRangeList(uint64_t RangeListOffset,
385
                         DWARFDebugRangeList &RangeList) const;
386
  void clear();
387
 
388
  const std::optional<StrOffsetsContributionDescriptor> &
389
  getStringOffsetsTableContribution() const {
390
    return StringOffsetsTableContribution;
391
  }
392
 
393
  uint8_t getDwarfStringOffsetsByteSize() const {
394
    assert(StringOffsetsTableContribution);
395
    return StringOffsetsTableContribution->getDwarfOffsetByteSize();
396
  }
397
 
398
  uint64_t getStringOffsetsBase() const {
399
    assert(StringOffsetsTableContribution);
400
    return StringOffsetsTableContribution->Base;
401
  }
402
 
403
  uint64_t getAbbreviationsOffset() const { return Header.getAbbrOffset(); }
404
 
405
  const DWARFAbbreviationDeclarationSet *getAbbreviations() const;
406
 
407
  static bool isMatchingUnitTypeAndTag(uint8_t UnitType, dwarf::Tag Tag) {
408
    switch (UnitType) {
409
    case dwarf::DW_UT_compile:
410
      return Tag == dwarf::DW_TAG_compile_unit;
411
    case dwarf::DW_UT_type:
412
      return Tag == dwarf::DW_TAG_type_unit;
413
    case dwarf::DW_UT_partial:
414
      return Tag == dwarf::DW_TAG_partial_unit;
415
    case dwarf::DW_UT_skeleton:
416
      return Tag == dwarf::DW_TAG_skeleton_unit;
417
    case dwarf::DW_UT_split_compile:
418
    case dwarf::DW_UT_split_type:
419
      return dwarf::isUnitType(Tag);
420
    }
421
    return false;
422
  }
423
 
424
  std::optional<object::SectionedAddress> getBaseAddress();
425
 
426
  DWARFDie getUnitDIE(bool ExtractUnitDIEOnly = true) {
427
    extractDIEsIfNeeded(ExtractUnitDIEOnly);
428
    if (DieArray.empty())
429
      return DWARFDie();
430
    return DWARFDie(this, &DieArray[0]);
431
  }
432
 
433
  DWARFDie getNonSkeletonUnitDIE(bool ExtractUnitDIEOnly = true,
434
                                 StringRef DWOAlternativeLocation = {}) {
435
    parseDWO(DWOAlternativeLocation);
436
    return DWO ? DWO->getUnitDIE(ExtractUnitDIEOnly)
437
               : getUnitDIE(ExtractUnitDIEOnly);
438
  }
439
 
440
  const char *getCompilationDir();
441
  std::optional<uint64_t> getDWOId() {
442
    extractDIEsIfNeeded(/*CUDieOnly*/ true);
443
    return getHeader().getDWOId();
444
  }
445
  void setDWOId(uint64_t NewID) { Header.setDWOId(NewID); }
446
 
447
  /// Return a vector of address ranges resulting from a (possibly encoded)
448
  /// range list starting at a given offset in the appropriate ranges section.
449
  Expected<DWARFAddressRangesVector> findRnglistFromOffset(uint64_t Offset);
450
 
451
  /// Return a vector of address ranges retrieved from an encoded range
452
  /// list whose offset is found via a table lookup given an index (DWARF v5
453
  /// and later).
454
  Expected<DWARFAddressRangesVector> findRnglistFromIndex(uint32_t Index);
455
 
456
  /// Return a rangelist's offset based on an index. The index designates
457
  /// an entry in the rangelist table's offset array and is supplied by
458
  /// DW_FORM_rnglistx.
459
  std::optional<uint64_t> getRnglistOffset(uint32_t Index);
460
 
461
  std::optional<uint64_t> getLoclistOffset(uint32_t Index);
462
 
463
  Expected<DWARFAddressRangesVector> collectAddressRanges();
464
 
465
  Expected<DWARFLocationExpressionsVector>
466
  findLoclistFromOffset(uint64_t Offset);
467
 
468
  /// Returns subprogram DIE with address range encompassing the provided
469
  /// address. The pointer is alive as long as parsed compile unit DIEs are not
470
  /// cleared.
471
  DWARFDie getSubroutineForAddress(uint64_t Address);
472
 
473
  /// Returns variable DIE for the address provided. The pointer is alive as
474
  /// long as parsed compile unit DIEs are not cleared.
475
  DWARFDie getVariableForAddress(uint64_t Address);
476
 
477
  /// getInlinedChainForAddress - fetches inlined chain for a given address.
478
  /// Returns empty chain if there is no subprogram containing address. The
479
  /// chain is valid as long as parsed compile unit DIEs are not cleared.
480
  void getInlinedChainForAddress(uint64_t Address,
481
                                 SmallVectorImpl<DWARFDie> &InlinedChain);
482
 
483
  /// Return the DWARFUnitVector containing this unit.
484
  const DWARFUnitVector &getUnitVector() const { return UnitVector; }
485
 
486
  /// Returns the number of DIEs in the unit. Parses the unit
487
  /// if necessary.
488
  unsigned getNumDIEs() {
489
    extractDIEsIfNeeded(false);
490
    return DieArray.size();
491
  }
492
 
493
  /// Return the index of a DIE inside the unit's DIE vector.
494
  ///
495
  /// It is illegal to call this method with a DIE that hasn't be
496
  /// created by this unit. In other word, it's illegal to call this
497
  /// method on a DIE that isn't accessible by following
498
  /// children/sibling links starting from this unit's getUnitDIE().
499
  uint32_t getDIEIndex(const DWARFDie &D) const {
500
    return getDIEIndex(D.getDebugInfoEntry());
501
  }
502
 
503
  /// Return the DIE object at the given index \p Index.
504
  DWARFDie getDIEAtIndex(unsigned Index) {
505
    return DWARFDie(this, getDebugInfoEntry(Index));
506
  }
507
 
508
  DWARFDie getParent(const DWARFDebugInfoEntry *Die);
509
  DWARFDie getSibling(const DWARFDebugInfoEntry *Die);
510
  DWARFDie getPreviousSibling(const DWARFDebugInfoEntry *Die);
511
  DWARFDie getFirstChild(const DWARFDebugInfoEntry *Die);
512
  DWARFDie getLastChild(const DWARFDebugInfoEntry *Die);
513
 
514
  /// Return the DIE object for a given offset \p Offset inside the
515
  /// unit's DIE vector.
516
  DWARFDie getDIEForOffset(uint64_t Offset) {
517
    if (std::optional<uint32_t> DieIdx = getDIEIndexForOffset(Offset))
518
      return DWARFDie(this, &DieArray[*DieIdx]);
519
 
520
    return DWARFDie();
521
  }
522
 
523
  /// Return the DIE index for a given offset \p Offset inside the
524
  /// unit's DIE vector.
525
  std::optional<uint32_t> getDIEIndexForOffset(uint64_t Offset) {
526
    extractDIEsIfNeeded(false);
527
    auto It =
528
        llvm::partition_point(DieArray, [=](const DWARFDebugInfoEntry &DIE) {
529
          return DIE.getOffset() < Offset;
530
        });
531
    if (It != DieArray.end() && It->getOffset() == Offset)
532
      return It - DieArray.begin();
533
    return std::nullopt;
534
  }
535
 
536
  uint32_t getLineTableOffset() const {
537
    if (auto IndexEntry = Header.getIndexEntry())
538
      if (const auto *Contrib = IndexEntry->getContribution(DW_SECT_LINE))
539
        return Contrib->getOffset32();
540
    return 0;
541
  }
542
 
543
  die_iterator_range dies() {
544
    extractDIEsIfNeeded(false);
545
    return die_iterator_range(DieArray.begin(), DieArray.end());
546
  }
547
 
548
  virtual void dump(raw_ostream &OS, DIDumpOptions DumpOpts) = 0;
549
 
550
  Error tryExtractDIEsIfNeeded(bool CUDieOnly);
551
 
552
private:
553
  /// Size in bytes of the .debug_info data associated with this compile unit.
554
  size_t getDebugInfoSize() const {
555
    return Header.getLength() + Header.getUnitLengthFieldByteSize() -
556
           getHeaderSize();
557
  }
558
 
559
  /// extractDIEsIfNeeded - Parses a compile unit and indexes its DIEs if it
560
  /// hasn't already been done
561
  void extractDIEsIfNeeded(bool CUDieOnly);
562
 
563
  /// extractDIEsToVector - Appends all parsed DIEs to a vector.
564
  void extractDIEsToVector(bool AppendCUDie, bool AppendNonCUDIEs,
565
                           std::vector<DWARFDebugInfoEntry> &DIEs) const;
566
 
567
  /// clearDIEs - Clear parsed DIEs to keep memory usage low.
568
  void clearDIEs(bool KeepCUDie);
569
 
570
  /// parseDWO - Parses .dwo file for current compile unit. Returns true if
571
  /// it was actually constructed.
572
  /// The \p AlternativeLocation specifies an alternative location to get
573
  /// the DWARF context for the DWO object; this is the case when it has
574
  /// been moved from its original location.
575
  bool parseDWO(StringRef AlternativeLocation = {});
576
};
577
 
578
inline bool isCompileUnit(const std::unique_ptr<DWARFUnit> &U) {
579
  return !U->isTypeUnit();
580
}
581
 
582
} // end namespace llvm
583
 
584
#endif // LLVM_DEBUGINFO_DWARF_DWARFUNIT_H