xref: /freebsd/contrib/llvm-project/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 //===- DWARFUnit.h ----------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // 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 namespace dwarf_linker {
47 namespace parallel {
48 class CompileUnit;
49 }
50 } // namespace dwarf_linker
51 
52 /// Base class describing the header of any kind of "unit."  Some information
53 /// is specific to certain unit types.  We separate this class out so we can
54 /// parse the header before deciding what specific kind of unit to construct.
55 class DWARFUnitHeader {
56   // Offset within section.
57   uint64_t Offset = 0;
58   // Version, address size, and DWARF format.
59   dwarf::FormParams FormParams;
60   uint64_t Length = 0;
61   uint64_t AbbrOffset = 0;
62 
63   // For DWO units only.
64   const DWARFUnitIndex::Entry *IndexEntry = nullptr;
65 
66   // For type units only.
67   uint64_t TypeHash = 0;
68   uint64_t TypeOffset = 0;
69 
70   // For v5 split or skeleton compile units only.
71   std::optional<uint64_t> DWOId;
72 
73   // Unit type as parsed, or derived from the section kind.
74   uint8_t UnitType = 0;
75 
76   // Size as parsed. uint8_t for compactness.
77   uint8_t Size = 0;
78 
79 public:
80   /// Parse a unit header from \p debug_info starting at \p offset_ptr.
81   /// Note that \p SectionKind is used as a hint to guess the unit type
82   /// for DWARF formats prior to DWARFv5. In DWARFv5 the unit type is
83   /// explicitly defined in the header and the hint is ignored.
84   Error extract(DWARFContext &Context, const DWARFDataExtractor &debug_info,
85                 uint64_t *offset_ptr, DWARFSectionKind SectionKind);
86   // For units in DWARF Package File, remember the index entry and update
87   // the abbreviation offset read by extract().
88   Error applyIndexEntry(const DWARFUnitIndex::Entry *Entry);
getOffset()89   uint64_t getOffset() const { return Offset; }
getFormParams()90   const dwarf::FormParams &getFormParams() const { return FormParams; }
getVersion()91   uint16_t getVersion() const { return FormParams.Version; }
getFormat()92   dwarf::DwarfFormat getFormat() const { return FormParams.Format; }
getAddressByteSize()93   uint8_t getAddressByteSize() const { return FormParams.AddrSize; }
getRefAddrByteSize()94   uint8_t getRefAddrByteSize() const { return FormParams.getRefAddrByteSize(); }
getDwarfOffsetByteSize()95   uint8_t getDwarfOffsetByteSize() const {
96     return FormParams.getDwarfOffsetByteSize();
97   }
getLength()98   uint64_t getLength() const { return Length; }
getAbbrOffset()99   uint64_t getAbbrOffset() const { return AbbrOffset; }
getDWOId()100   std::optional<uint64_t> getDWOId() const { return DWOId; }
setDWOId(uint64_t Id)101   void setDWOId(uint64_t Id) {
102     assert((!DWOId || *DWOId == Id) && "setting DWOId to a different value");
103     DWOId = Id;
104   }
getIndexEntry()105   const DWARFUnitIndex::Entry *getIndexEntry() const { return IndexEntry; }
getTypeHash()106   uint64_t getTypeHash() const { return TypeHash; }
getTypeOffset()107   uint64_t getTypeOffset() const { return TypeOffset; }
getUnitType()108   uint8_t getUnitType() const { return UnitType; }
isTypeUnit()109   bool isTypeUnit() const {
110     return UnitType == dwarf::DW_UT_type || UnitType == dwarf::DW_UT_split_type;
111   }
getSize()112   uint8_t getSize() const { return Size; }
getUnitLengthFieldByteSize()113   uint8_t getUnitLengthFieldByteSize() const {
114     return dwarf::getUnitLengthFieldByteSize(FormParams.Format);
115   }
getNextUnitOffset()116   uint64_t getNextUnitOffset() const {
117     return Offset + Length + getUnitLengthFieldByteSize();
118   }
119 };
120 
121 const DWARFUnitIndex &getDWARFUnitIndex(DWARFContext &Context,
122                                         DWARFSectionKind Kind);
123 
124 bool isCompileUnit(const std::unique_ptr<DWARFUnit> &U);
125 
126 /// Describe a collection of units. Intended to hold all units either from
127 /// .debug_info and .debug_types, or from .debug_info.dwo and .debug_types.dwo.
128 class DWARFUnitVector final : public SmallVector<std::unique_ptr<DWARFUnit>, 1> {
129   std::function<std::unique_ptr<DWARFUnit>(uint64_t, DWARFSectionKind,
130                                            const DWARFSection *,
131                                            const DWARFUnitIndex::Entry *)>
132       Parser;
133   int NumInfoUnits = -1;
134 
135 public:
136   using UnitVector = SmallVectorImpl<std::unique_ptr<DWARFUnit>>;
137   using iterator = typename UnitVector::iterator;
138   using iterator_range = llvm::iterator_range<typename UnitVector::iterator>;
139 
140   using compile_unit_range =
141       decltype(make_filter_range(std::declval<iterator_range>(), isCompileUnit));
142 
143   DWARFUnit *getUnitForOffset(uint64_t Offset) const;
144   DWARFUnit *getUnitForIndexEntry(const DWARFUnitIndex::Entry &E);
145 
146   /// Read units from a .debug_info or .debug_types section.  Calls made
147   /// before finishedInfoUnits() are assumed to be for .debug_info sections,
148   /// calls after finishedInfoUnits() are for .debug_types sections.  Caller
149   /// must not mix calls to addUnitsForSection and addUnitsForDWOSection.
150   void addUnitsForSection(DWARFContext &C, const DWARFSection &Section,
151                           DWARFSectionKind SectionKind);
152   /// Read units from a .debug_info.dwo or .debug_types.dwo section.  Calls
153   /// made before finishedInfoUnits() are assumed to be for .debug_info.dwo
154   /// sections, calls after finishedInfoUnits() are for .debug_types.dwo
155   /// sections.  Caller must not mix calls to addUnitsForSection and
156   /// addUnitsForDWOSection.
157   void addUnitsForDWOSection(DWARFContext &C, const DWARFSection &DWOSection,
158                              DWARFSectionKind SectionKind, bool Lazy = false);
159 
160   /// Add an existing DWARFUnit to this UnitVector. This is used by the DWARF
161   /// verifier to process unit separately.
162   DWARFUnit *addUnit(std::unique_ptr<DWARFUnit> Unit);
163 
164   /// Returns number of all units held by this instance.
getNumUnits()165   unsigned getNumUnits() const { return size(); }
166   /// Returns number of units from all .debug_info[.dwo] sections.
getNumInfoUnits()167   unsigned getNumInfoUnits() const {
168     return NumInfoUnits == -1 ? size() : NumInfoUnits;
169   }
170   /// Returns number of units from all .debug_types[.dwo] sections.
getNumTypesUnits()171   unsigned getNumTypesUnits() const { return size() - NumInfoUnits; }
172   /// Indicate that parsing .debug_info[.dwo] is done, and remaining units
173   /// will be from .debug_types[.dwo].
finishedInfoUnits()174   void finishedInfoUnits() { NumInfoUnits = size(); }
175 
176 private:
177   void addUnitsImpl(DWARFContext &Context, const DWARFObject &Obj,
178                     const DWARFSection &Section, const DWARFDebugAbbrev *DA,
179                     const DWARFSection *RS, const DWARFSection *LocSection,
180                     StringRef SS, const DWARFSection &SOS,
181                     const DWARFSection *AOS, const DWARFSection &LS, bool LE,
182                     bool IsDWO, bool Lazy, DWARFSectionKind SectionKind);
183 };
184 
185 /// Represents base address of the CU.
186 /// Represents a unit's contribution to the string offsets table.
187 struct StrOffsetsContributionDescriptor {
188   uint64_t Base = 0;
189   /// The contribution size not including the header.
190   uint64_t Size = 0;
191   /// Format and version.
192   dwarf::FormParams FormParams = {0, 0, dwarf::DwarfFormat::DWARF32};
193 
StrOffsetsContributionDescriptorStrOffsetsContributionDescriptor194   StrOffsetsContributionDescriptor(uint64_t Base, uint64_t Size,
195                                    uint8_t Version, dwarf::DwarfFormat Format)
196       : Base(Base), Size(Size), FormParams({Version, 0, Format}) {}
197   StrOffsetsContributionDescriptor() = default;
198 
getVersionStrOffsetsContributionDescriptor199   uint8_t getVersion() const { return FormParams.Version; }
getFormatStrOffsetsContributionDescriptor200   dwarf::DwarfFormat getFormat() const { return FormParams.Format; }
getDwarfOffsetByteSizeStrOffsetsContributionDescriptor201   uint8_t getDwarfOffsetByteSize() const {
202     return FormParams.getDwarfOffsetByteSize();
203   }
204   /// Determine whether a contribution to the string offsets table is
205   /// consistent with the relevant section size and that its length is
206   /// a multiple of the size of one of its entries.
207   Expected<StrOffsetsContributionDescriptor>
208   validateContributionSize(DWARFDataExtractor &DA);
209 };
210 
211 class DWARFUnit {
212   DWARFContext &Context;
213   /// Section containing this DWARFUnit.
214   const DWARFSection &InfoSection;
215 
216   DWARFUnitHeader Header;
217   const DWARFDebugAbbrev *Abbrev;
218   const DWARFSection *RangeSection;
219   uint64_t RangeSectionBase;
220   uint64_t LocSectionBase;
221 
222   /// Location table of this unit.
223   std::unique_ptr<DWARFLocationTable> LocTable;
224 
225   const DWARFSection &LineSection;
226   StringRef StringSection;
227   const DWARFSection &StringOffsetSection;
228   const DWARFSection *AddrOffsetSection;
229   DWARFUnit *SU;
230   std::optional<uint64_t> AddrOffsetSectionBase;
231   bool IsLittleEndian;
232   bool IsDWO;
233   const DWARFUnitVector &UnitVector;
234 
235   /// Start, length, and DWARF format of the unit's contribution to the string
236   /// offsets table (DWARF v5).
237   std::optional<StrOffsetsContributionDescriptor>
238       StringOffsetsTableContribution;
239 
240   mutable const DWARFAbbreviationDeclarationSet *Abbrevs;
241   std::optional<object::SectionedAddress> BaseAddr;
242   /// The compile unit debug information entry items.
243   std::vector<DWARFDebugInfoEntry> DieArray;
244 
245   /// Map from range's start address to end address and corresponding DIE.
246   /// IntervalMap does not support range removal, as a result, we use the
247   /// std::map::upper_bound for address range lookup.
248   std::map<uint64_t, std::pair<uint64_t, DWARFDie>> AddrDieMap;
249 
250   /// Map from the location (interpreted DW_AT_location) of a DW_TAG_variable,
251   /// to the end address and the corresponding DIE.
252   std::map<uint64_t, std::pair<uint64_t, DWARFDie>> VariableDieMap;
253   DenseSet<uint64_t> RootsParsedForVariables;
254 
255   using die_iterator_range =
256       iterator_range<std::vector<DWARFDebugInfoEntry>::iterator>;
257 
258   std::shared_ptr<DWARFUnit> DWO;
259 
260 protected:
261   friend dwarf_linker::parallel::CompileUnit;
262 
263   /// Return the index of a \p Die entry inside the unit's DIE vector.
264   ///
265   /// It is illegal to call this method with a DIE that hasn't be
266   /// created by this unit. In other word, it's illegal to call this
267   /// method on a DIE that isn't accessible by following
268   /// children/sibling links starting from this unit's getUnitDIE().
getDIEIndex(const DWARFDebugInfoEntry * Die)269   uint32_t getDIEIndex(const DWARFDebugInfoEntry *Die) const {
270     auto First = DieArray.data();
271     assert(Die >= First && Die < First + DieArray.size());
272     return Die - First;
273   }
274 
275   /// Return DWARFDebugInfoEntry for the specified index \p Index.
getDebugInfoEntry(unsigned Index)276   const DWARFDebugInfoEntry *getDebugInfoEntry(unsigned Index) const {
277     assert(Index < DieArray.size());
278     return &DieArray[Index];
279   }
280 
281   const DWARFDebugInfoEntry *
282   getParentEntry(const DWARFDebugInfoEntry *Die) const;
283   const DWARFDebugInfoEntry *
284   getSiblingEntry(const DWARFDebugInfoEntry *Die) const;
285   const DWARFDebugInfoEntry *
286   getPreviousSiblingEntry(const DWARFDebugInfoEntry *Die) const;
287   const DWARFDebugInfoEntry *
288   getFirstChildEntry(const DWARFDebugInfoEntry *Die) const;
289   const DWARFDebugInfoEntry *
290   getLastChildEntry(const DWARFDebugInfoEntry *Die) const;
291 
getHeader()292   const DWARFUnitHeader &getHeader() const { return Header; }
293 
294   /// Find the unit's contribution to the string offsets table and determine its
295   /// length and form. The given offset is expected to be derived from the unit
296   /// DIE's DW_AT_str_offsets_base attribute.
297   Expected<std::optional<StrOffsetsContributionDescriptor>>
298   determineStringOffsetsTableContribution(DWARFDataExtractor &DA);
299 
300   /// Find the unit's contribution to the string offsets table and determine its
301   /// length and form. The given offset is expected to be 0 in a dwo file or,
302   /// in a dwp file, the start of the unit's contribution to the string offsets
303   /// table section (as determined by the index table).
304   Expected<std::optional<StrOffsetsContributionDescriptor>>
305   determineStringOffsetsTableContributionDWO(DWARFDataExtractor &DA);
306 
307 public:
308   DWARFUnit(DWARFContext &Context, const DWARFSection &Section,
309             const DWARFUnitHeader &Header, const DWARFDebugAbbrev *DA,
310             const DWARFSection *RS, const DWARFSection *LocSection,
311             StringRef SS, const DWARFSection &SOS, const DWARFSection *AOS,
312             const DWARFSection &LS, bool LE, bool IsDWO,
313             const DWARFUnitVector &UnitVector);
314 
315   virtual ~DWARFUnit();
316 
isLittleEndian()317   bool isLittleEndian() const { return IsLittleEndian; }
isDWOUnit()318   bool isDWOUnit() const { return IsDWO; }
getContext()319   DWARFContext& getContext() const { return Context; }
getInfoSection()320   const DWARFSection &getInfoSection() const { return InfoSection; }
getOffset()321   uint64_t getOffset() const { return Header.getOffset(); }
getFormParams()322   const dwarf::FormParams &getFormParams() const {
323     return Header.getFormParams();
324   }
getVersion()325   uint16_t getVersion() const { return Header.getVersion(); }
getAddressByteSize()326   uint8_t getAddressByteSize() const { return Header.getAddressByteSize(); }
getRefAddrByteSize()327   uint8_t getRefAddrByteSize() const { return Header.getRefAddrByteSize(); }
getDwarfOffsetByteSize()328   uint8_t getDwarfOffsetByteSize() const {
329     return Header.getDwarfOffsetByteSize();
330   }
331   /// Size in bytes of the parsed unit header.
getHeaderSize()332   uint32_t getHeaderSize() const { return Header.getSize(); }
getLength()333   uint64_t getLength() const { return Header.getLength(); }
getFormat()334   dwarf::DwarfFormat getFormat() const { return Header.getFormat(); }
getUnitType()335   uint8_t getUnitType() const { return Header.getUnitType(); }
isTypeUnit()336   bool isTypeUnit() const { return Header.isTypeUnit(); }
getAbbrOffset()337   uint64_t getAbbrOffset() const { return Header.getAbbrOffset(); }
getNextUnitOffset()338   uint64_t getNextUnitOffset() const { return Header.getNextUnitOffset(); }
getLineSection()339   const DWARFSection &getLineSection() const { return LineSection; }
getStringSection()340   StringRef getStringSection() const { return StringSection; }
getStringOffsetSection()341   const DWARFSection &getStringOffsetSection() const {
342     return StringOffsetSection;
343   }
344 
setSkeletonUnit(DWARFUnit * SU)345   void setSkeletonUnit(DWARFUnit *SU) { this->SU = SU; }
346   // Returns itself if not using Split DWARF, or if the unit is a skeleton unit
347   // - otherwise returns the split full unit's corresponding skeleton, if
348   // available.
getLinkedUnit()349   DWARFUnit *getLinkedUnit() { return IsDWO ? SU : this; }
350 
setAddrOffsetSection(const DWARFSection * AOS,uint64_t Base)351   void setAddrOffsetSection(const DWARFSection *AOS, uint64_t Base) {
352     AddrOffsetSection = AOS;
353     AddrOffsetSectionBase = Base;
354   }
355 
getAddrOffsetSectionBase()356   std::optional<uint64_t> getAddrOffsetSectionBase() const {
357     return AddrOffsetSectionBase;
358   }
359 
360   /// Returns offset to the indexed address value inside .debug_addr section.
getIndexedAddressOffset(uint64_t Index)361   std::optional<uint64_t> getIndexedAddressOffset(uint64_t Index) {
362     if (std::optional<uint64_t> AddrOffsetSectionBase =
363             getAddrOffsetSectionBase())
364       return *AddrOffsetSectionBase + Index * getAddressByteSize();
365 
366     return std::nullopt;
367   }
368 
369   /// Recursively update address to Die map.
370   void updateAddressDieMap(DWARFDie Die);
371 
372   /// Recursively update address to variable Die map.
373   void updateVariableDieMap(DWARFDie Die);
374 
setRangesSection(const DWARFSection * RS,uint64_t Base)375   void setRangesSection(const DWARFSection *RS, uint64_t Base) {
376     RangeSection = RS;
377     RangeSectionBase = Base;
378   }
379 
getLocSectionBase()380   uint64_t getLocSectionBase() const {
381     return LocSectionBase;
382   }
383 
384   std::optional<object::SectionedAddress>
385   getAddrOffsetSectionItem(uint32_t Index) const;
386   Expected<uint64_t> getStringOffsetSectionItem(uint32_t Index) const;
387 
388   DWARFDataExtractor getDebugInfoExtractor() const;
389 
getStringExtractor()390   DataExtractor getStringExtractor() const {
391     return DataExtractor(StringSection, false, 0);
392   }
393 
getLocationTable()394   const DWARFLocationTable &getLocationTable() { return *LocTable; }
395 
396   /// Extract the range list referenced by this compile unit from the
397   /// .debug_ranges section. If the extraction is unsuccessful, an error
398   /// is returned. Successful extraction requires that the compile unit
399   /// has already been extracted.
400   Error extractRangeList(uint64_t RangeListOffset,
401                          DWARFDebugRangeList &RangeList) const;
402   void clear();
403 
404   const std::optional<StrOffsetsContributionDescriptor> &
getStringOffsetsTableContribution()405   getStringOffsetsTableContribution() {
406     extractDIEsIfNeeded(true /*CUDIeOnly*/);
407     return StringOffsetsTableContribution;
408   }
409 
getDwarfStringOffsetsByteSize()410   uint8_t getDwarfStringOffsetsByteSize() const {
411     assert(StringOffsetsTableContribution);
412     return StringOffsetsTableContribution->getDwarfOffsetByteSize();
413   }
414 
getStringOffsetsBase()415   uint64_t getStringOffsetsBase() const {
416     assert(StringOffsetsTableContribution);
417     return StringOffsetsTableContribution->Base;
418   }
419 
getAbbreviationsOffset()420   uint64_t getAbbreviationsOffset() const { return Header.getAbbrOffset(); }
421 
422   const DWARFAbbreviationDeclarationSet *getAbbreviations() const;
423 
isMatchingUnitTypeAndTag(uint8_t UnitType,dwarf::Tag Tag)424   static bool isMatchingUnitTypeAndTag(uint8_t UnitType, dwarf::Tag Tag) {
425     switch (UnitType) {
426     case dwarf::DW_UT_compile:
427       return Tag == dwarf::DW_TAG_compile_unit;
428     case dwarf::DW_UT_type:
429       return Tag == dwarf::DW_TAG_type_unit;
430     case dwarf::DW_UT_partial:
431       return Tag == dwarf::DW_TAG_partial_unit;
432     case dwarf::DW_UT_skeleton:
433       return Tag == dwarf::DW_TAG_skeleton_unit;
434     case dwarf::DW_UT_split_compile:
435     case dwarf::DW_UT_split_type:
436       return dwarf::isUnitType(Tag);
437     }
438     return false;
439   }
440 
441   std::optional<object::SectionedAddress> getBaseAddress();
442 
443   DWARFDie getUnitDIE(bool ExtractUnitDIEOnly = true) {
444     extractDIEsIfNeeded(ExtractUnitDIEOnly);
445     if (DieArray.empty())
446       return DWARFDie();
447     return DWARFDie(this, &DieArray[0]);
448   }
449 
450   DWARFDie getNonSkeletonUnitDIE(bool ExtractUnitDIEOnly = true,
451                                  StringRef DWOAlternativeLocation = {}) {
452     parseDWO(DWOAlternativeLocation);
453     return DWO ? DWO->getUnitDIE(ExtractUnitDIEOnly)
454                : getUnitDIE(ExtractUnitDIEOnly);
455   }
456 
457   const char *getCompilationDir();
getDWOId()458   std::optional<uint64_t> getDWOId() {
459     extractDIEsIfNeeded(/*CUDieOnly*/ true);
460     return getHeader().getDWOId();
461   }
setDWOId(uint64_t NewID)462   void setDWOId(uint64_t NewID) { Header.setDWOId(NewID); }
463 
464   /// Return a vector of address ranges resulting from a (possibly encoded)
465   /// range list starting at a given offset in the appropriate ranges section.
466   Expected<DWARFAddressRangesVector> findRnglistFromOffset(uint64_t Offset);
467 
468   /// Return a vector of address ranges retrieved from an encoded range
469   /// list whose offset is found via a table lookup given an index (DWARF v5
470   /// and later).
471   Expected<DWARFAddressRangesVector> findRnglistFromIndex(uint32_t Index);
472 
473   /// Return a rangelist's offset based on an index. The index designates
474   /// an entry in the rangelist table's offset array and is supplied by
475   /// DW_FORM_rnglistx.
476   std::optional<uint64_t> getRnglistOffset(uint32_t Index);
477 
478   std::optional<uint64_t> getLoclistOffset(uint32_t Index);
479 
480   Expected<DWARFAddressRangesVector> collectAddressRanges();
481 
482   Expected<DWARFLocationExpressionsVector>
483   findLoclistFromOffset(uint64_t Offset);
484 
485   /// Returns subprogram DIE with address range encompassing the provided
486   /// address. The pointer is alive as long as parsed compile unit DIEs are not
487   /// cleared.
488   DWARFDie getSubroutineForAddress(uint64_t Address);
489 
490   /// Returns variable DIE for the address provided. The pointer is alive as
491   /// long as parsed compile unit DIEs are not cleared.
492   DWARFDie getVariableForAddress(uint64_t Address);
493 
494   /// getInlinedChainForAddress - fetches inlined chain for a given address.
495   /// Returns empty chain if there is no subprogram containing address. The
496   /// chain is valid as long as parsed compile unit DIEs are not cleared.
497   void getInlinedChainForAddress(uint64_t Address,
498                                  SmallVectorImpl<DWARFDie> &InlinedChain);
499 
500   /// Return the DWARFUnitVector containing this unit.
getUnitVector()501   const DWARFUnitVector &getUnitVector() const { return UnitVector; }
502 
503   /// Returns the number of DIEs in the unit. Parses the unit
504   /// if necessary.
getNumDIEs()505   unsigned getNumDIEs() {
506     extractDIEsIfNeeded(false);
507     return DieArray.size();
508   }
509 
510   /// Return the index of a DIE inside the unit's DIE vector.
511   ///
512   /// It is illegal to call this method with a DIE that hasn't be
513   /// created by this unit. In other word, it's illegal to call this
514   /// method on a DIE that isn't accessible by following
515   /// children/sibling links starting from this unit's getUnitDIE().
getDIEIndex(const DWARFDie & D)516   uint32_t getDIEIndex(const DWARFDie &D) const {
517     return getDIEIndex(D.getDebugInfoEntry());
518   }
519 
520   /// Return the DIE object at the given index \p Index.
getDIEAtIndex(unsigned Index)521   DWARFDie getDIEAtIndex(unsigned Index) {
522     return DWARFDie(this, getDebugInfoEntry(Index));
523   }
524 
525   DWARFDie getParent(const DWARFDebugInfoEntry *Die);
526   DWARFDie getSibling(const DWARFDebugInfoEntry *Die);
527   DWARFDie getPreviousSibling(const DWARFDebugInfoEntry *Die);
528   DWARFDie getFirstChild(const DWARFDebugInfoEntry *Die);
529   DWARFDie getLastChild(const DWARFDebugInfoEntry *Die);
530 
531   /// Return the DIE object for a given offset \p Offset inside the
532   /// unit's DIE vector.
getDIEForOffset(uint64_t Offset)533   DWARFDie getDIEForOffset(uint64_t Offset) {
534     if (std::optional<uint32_t> DieIdx = getDIEIndexForOffset(Offset))
535       return DWARFDie(this, &DieArray[*DieIdx]);
536 
537     return DWARFDie();
538   }
539 
540   /// Return the DIE index for a given offset \p Offset inside the
541   /// unit's DIE vector.
getDIEIndexForOffset(uint64_t Offset)542   std::optional<uint32_t> getDIEIndexForOffset(uint64_t Offset) {
543     extractDIEsIfNeeded(false);
544     auto It =
545         llvm::partition_point(DieArray, [=](const DWARFDebugInfoEntry &DIE) {
546           return DIE.getOffset() < Offset;
547         });
548     if (It != DieArray.end() && It->getOffset() == Offset)
549       return It - DieArray.begin();
550     return std::nullopt;
551   }
552 
getLineTableOffset()553   uint32_t getLineTableOffset() const {
554     if (auto IndexEntry = Header.getIndexEntry())
555       if (const auto *Contrib = IndexEntry->getContribution(DW_SECT_LINE))
556         return Contrib->getOffset32();
557     return 0;
558   }
559 
dies()560   die_iterator_range dies() {
561     extractDIEsIfNeeded(false);
562     return die_iterator_range(DieArray.begin(), DieArray.end());
563   }
564 
565   virtual void dump(raw_ostream &OS, DIDumpOptions DumpOpts) = 0;
566 
567   Error tryExtractDIEsIfNeeded(bool CUDieOnly);
568 
569 private:
570   /// Size in bytes of the .debug_info data associated with this compile unit.
getDebugInfoSize()571   size_t getDebugInfoSize() const {
572     return Header.getLength() + Header.getUnitLengthFieldByteSize() -
573            getHeaderSize();
574   }
575 
576   /// extractDIEsIfNeeded - Parses a compile unit and indexes its DIEs if it
577   /// hasn't already been done
578   void extractDIEsIfNeeded(bool CUDieOnly);
579 
580   /// extractDIEsToVector - Appends all parsed DIEs to a vector.
581   void extractDIEsToVector(bool AppendCUDie, bool AppendNonCUDIEs,
582                            std::vector<DWARFDebugInfoEntry> &DIEs) const;
583 
584   /// clearDIEs - Clear parsed DIEs to keep memory usage low.
585   void clearDIEs(bool KeepCUDie);
586 
587   /// parseDWO - Parses .dwo file for current compile unit. Returns true if
588   /// it was actually constructed.
589   /// The \p AlternativeLocation specifies an alternative location to get
590   /// the DWARF context for the DWO object; this is the case when it has
591   /// been moved from its original location.
592   bool parseDWO(StringRef AlternativeLocation = {});
593 };
594 
isCompileUnit(const std::unique_ptr<DWARFUnit> & U)595 inline bool isCompileUnit(const std::unique_ptr<DWARFUnit> &U) {
596   return !U->isTypeUnit();
597 }
598 
599 } // end namespace llvm
600 
601 #endif // LLVM_DEBUGINFO_DWARF_DWARFUNIT_H
602