[BOLT][DWARF] Implement monolithic DWARF5

[ayermolo]

Summary

Added implementation to support DWARF5 in monolithic mode.
Next step DWARF5 split dwarf support.

[ayermolo]

rebase

[ayermolo]

rebase

[maksfb]

bolt/include/bolt/Core/DebugData.h

187

nit

214

The comment is out of sync.

217

Why do you need to redefine getKind()?

231

Is uint32_t enough to support DWARF-64 in the future?

285–286

Update the comment.

486

Could this be constexpr and defined here?

487

Likewise.

1093

nit

bolt/lib/Core/BinaryContext.cpp

1539

nit

bolt/lib/Core/DebugData.cpp

169

nit

187

210

227

405

415

nit

447

459

490

Expand auto.

574

604

650

1523–1524

bolt/lib/Rewrite/DWARFRewriter.cpp

84–88

495

No need to introduce the new scope unless you need it.

563–564

1591

[ayermolo]

bolt/include/bolt/Core/DebugData.h

231

no, but then rest of the code either.

[ayermolo]

addressing comments

[ayermolo]

addressed comments.

[ayermolo]

bolt/lib/Core/BinaryContext.cpp

1465

Add a warning if it's dwar5 and legacy

1507–1508

remove

1508

rename BinaryLineTable

bolt/lib/Core/DebugData.cpp

413

add const to this and AddrSize

420

add type

432

remove curly brases

455

lower case

1523

remove .

1556

const

bolt/lib/Rewrite/DWARFRewriter.cpp

376–377

remove space

591

Unit.getVersion()== 5

595

use braces for rest

605–606

const

613

const here and Index

668

rewrite to make sense

673

const

968

use curly

979

use curly

980

llvm_unreachable

[ayermolo]

addressing more comments

[ayermolo]

Change how we handle .debug_line_str

[DavidSpickett]

lldb/test/Shell/SymbolFile/DWARF/x86/DW_TAG_variable-DW_AT_decl_file-DW_AT_abstract_origin-crosscu1.s

17

Was this test just using whatever DWARF %clang_host defaulted to? (since I don't see any changes outside of bolt other than this)

[ayermolo]

lldb/test/Shell/SymbolFile/DWARF/x86/DW_TAG_variable-DW_AT_decl_file-DW_AT_abstract_origin-crosscu1.s

17

Yes.

[ayermolo]

nits

[maksfb]

LGTM

[Amir]

Hi,
The test started to fail on Ubuntu buildbot: https://lab.llvm.org/buildbot/#/builders/215/builds/6376

# PRECHECK: include_directories[ 0] = .debug_line_str[0x00000000]
            ^
<stdin>:8:12: note: scanning from here
 version: 5
           ^
<stdin>:30:1: note: possible intended match here
include_directories[ 0] = .debug_line_str[0x00000009] = "."

Can you please take a look?

[ayermolo]

In D121876#3542766, @Amir wrote:

Hi,
The test started to fail on Ubuntu buildbot: https://lab.llvm.org/buildbot/#/builders/215/builds/6376

# PRECHECK: include_directories[ 0] = .debug_line_str[0x00000000]
            ^
<stdin>:8:12: note: scanning from here
 version: 5
           ^
<stdin>:30:1: note: possible intended match here
include_directories[ 0] = .debug_line_str[0x00000009] = "."

Can you please take a look?

Fixed in: D126733. Was due to LLD change.

bolt/include/bolt/Core/BinaryContext.h

class BinaryContext {
 
   /// DWP Context.
   std::shared_ptr<DWARFContext> DWPContext;
 
   /// A map of DWO Ids to CUs.
   using DWOIdToCUMapType = std::unordered_map<uint64_t, DWARFUnit *>;
   DWOIdToCUMapType DWOCUs;
 
+  bool ContainsDwarf5{false};
+  bool ContainsDwarfLegacy{false};
+
   /// Preprocess DWO debug information.
   void preprocessDWODebugInfo();
 
   /// DWARF line info for CUs.
   std::map<unsigned, DwarfLineTable> DwarfLineTablesCUMap;
 
 public:
   static Expected<std::unique_ptr<BinaryContext>>
public:
   Optional<DWARFUnit *> getDWOCU(uint64_t DWOId);
 
   /// Returns DWOContext if it exists.
   DWARFContext *getDWOContext();
 
   /// Get Number of DWOCUs in a map.
   uint32_t getNumDWOCUs() { return DWOCUs.size(); }
 
-  const std::map<unsigned, DwarfLineTable> &getDwarfLineTables() const {
+  /// Returns true if DWARF5 is used.
+  bool isDWARF5Used() const { return ContainsDwarf5; }
+
+  /// Returns true if DWARF4 or lower is used.
+  bool isDWARFLegacyUsed() const { return ContainsDwarfLegacy; }
+
+  std::map<unsigned, DwarfLineTable> &getDwarfLineTables() {
     return DwarfLineTablesCUMap;
   }
 
   DwarfLineTable &getDwarfLineTable(unsigned CUID) {
     return DwarfLineTablesCUMap[CUID];
   }
 
   Expected<unsigned> getDwarfFile(StringRef Directory, StringRef FileName,
                                   unsigned FileNumber,
                                   Optional<MD5::MD5Result> Checksum,
-                                  Optional<StringRef> Source, unsigned CUID);
+                                  Optional<StringRef> Source, unsigned CUID,
+                                  unsigned DWARFVersion);
 
   /// [start memory address] -> [segment info] mapping.
   std::map<uint64_t, SegmentInfo> SegmentMapInfo;
 
   /// Symbols that are expected to be undefined in MCContext during emission.
   std::unordered_set<MCSymbol *> UndefinedSymbols;
 
   /// [name] -> [BinaryData*] map used for global symbol resolution.

bolt/include/bolt/Core/DebugData.h

 #include <vector>
 
 #define DWARF2_FLAG_END_SEQUENCE (1 << 4)
 
 namespace llvm {
 
 namespace bolt {
 
+// DWARF5 Header in order of encoding.
+// Types represent encodnig sizes.
+using UnitLengthType = uint32_t;
+using VersionType = uint16_t;
+using AddressSizeType = uint8_t;
+using SegmentSelectorType = uint8_t;
+using OffsetEntryCountType = uint32_t;
+/// Get DWARF5 Header size.
+/// Rangelists and Loclists have the same header.
+constexpr uint32_t getDWARF5RngListLocListHeaderSize() {
+  return sizeof(UnitLengthType) + sizeof(VersionType) +
+         sizeof(AddressSizeType) + sizeof(SegmentSelectorType) +
+         sizeof(OffsetEntryCountType);
+}
+
 class BinaryContext;
 
 /// Address range representation. Takes less space than DWARFAddressRange.
 struct DebugAddressRange {
   uint64_t LowPC{0};
   uint64_t HighPC{0};
 
   DebugAddressRange() = default;

 
 /// Map of old CU offset to new offset and length.
 struct CUInfo {
   uint32_t Offset;
   uint32_t Length;
 };
 using CUOffsetMap = std::map<uint32_t, CUInfo>;
 
+enum class RangesWriterKind { DebugRangesWriter, DebugRangeListsWriter };
 /// Serializes the .debug_ranges DWARF section.
 class DebugRangesSectionWriter {
 public:
   DebugRangesSectionWriter();
 
+  DebugRangesSectionWriter(RangesWriterKind K) : Kind(K){};
+
+  virtual ~DebugRangesSectionWriter(){};
+
   /// Add ranges with caching.
-  uint64_t
+  virtual uint64_t
   addRanges(DebugAddressRangesVector &&Ranges,
             std::map<DebugAddressRangesVector, uint64_t> &CachedRanges);
 
   /// Add ranges and return offset into section.
-  uint64_t addRanges(const DebugAddressRangesVector &Ranges);
+  virtual uint64_t addRanges(const DebugAddressRangesVector &Ranges);
 
   /// Returns an offset of an empty address ranges list that is always written
   /// to .debug_ranges
   uint64_t getEmptyRangesOffset() const { return EmptyRangesOffset; }
 
   /// Returns the SectionOffset.
   uint64_t getSectionOffset();
 
-  std::unique_ptr<DebugBufferVector> finalize() {
+  /// Returns a buffer containing Ranges.
+  virtual std::unique_ptr<DebugBufferVector> finalize() {
     return std::move(RangesBuffer);
   }
 
-private:
+  RangesWriterKind getKind() const { return Kind; }
+
+  static bool classof(const DebugRangesSectionWriter *Writer) {
+    return Writer->getKind() == RangesWriterKind::DebugRangesWriter;
+  }
+
+protected:
   std::unique_ptr<DebugBufferVector> RangesBuffer;
 
   std::unique_ptr<raw_svector_ostream> RangesStream;
 
   std::mutex WriterMutex;
 
   /// Current offset in the section (updated as new entries are written).
   /// Starts with 16 since the first 16 bytes are reserved for an empty range.
   uint32_t SectionOffset{0};
 
   /// Offset of an empty address ranges list.
   static constexpr uint64_t EmptyRangesOffset{0};
+
+private:
+  RangesWriterKind Kind;
+};
+
+class DebugAddrWriter;
+class DebugRangeListsSectionWriter : public DebugRangesSectionWriter {
+public:
+  DebugRangeListsSectionWriter()
+      : DebugRangesSectionWriter(RangesWriterKind::DebugRangeListsWriter) {
+    RangesBuffer = std::make_unique<DebugBufferVector>();
+    RangesStream = std::make_unique<raw_svector_ostream>(*RangesBuffer);
+  };
+  virtual ~DebugRangeListsSectionWriter(){};
+
+  static void setAddressWriter(DebugAddrWriter *AddrW) { AddrWriter = AddrW; }
+
+  /// Add ranges with caching.
+  virtual uint64_t addRanges(
+      DebugAddressRangesVector &&Ranges,
+      std::map<DebugAddressRangesVector, uint64_t> &CachedRanges) override;
+
+  /// Add ranges and return offset into section.
+  virtual uint64_t addRanges(const DebugAddressRangesVector &Ranges) override;
+
+  virtual std::unique_ptr<DebugBufferVector> finalize() override {
+    return std::move(RangesBuffer);
+  }
+
+  /// Needs to be invoked before each CU is processed.
+  /// \p CUID is a unique ID of each CU.
+  void initSection(uint64_t CUID);
+
+  /// Writes out range lists for a current CU being processed.
+  void finalizeSection();
+
+  static bool classof(const DebugRangesSectionWriter *Writer) {
+    return Writer->getKind() == RangesWriterKind::DebugRangeListsWriter;
+  }
+
+private:
+  static DebugAddrWriter *AddrWriter;
+  /// Unique ID of CU being processed.
+  uint64_t CUID{0};
+  /// Current relative offset of range list entry within this CUs rangelist
+  /// body.
+  uint32_t CurrentOffset{0};
+  /// Contains relative offset of each range list entry.
+  SmallVector<uint32_t, 1> RangeEntries;
+
+  std::unique_ptr<DebugBufferVector> CUBodyBuffer;
+  std::unique_ptr<raw_svector_ostream> CUBodyStream;
 };
 
 /// Serializes the .debug_aranges DWARF section.
 class DebugARangesSectionWriter {
 public:
   /// Add ranges for CU matching \p CUOffset.
   void addCURanges(uint64_t CUOffset, DebugAddressRangesVector &&Ranges);
 

 using IndexAddressPair = std::pair<uint32_t, uint64_t>;
 using AddressToIndexMap = std::unordered_map<uint64_t, uint32_t>;
 using IndexToAddressMap = std::unordered_map<uint32_t, uint64_t>;
 using AddressSectionBuffer = SmallVector<char, 4>;
 class DebugAddrWriter {
 public:
   DebugAddrWriter() = delete;
   DebugAddrWriter(BinaryContext *BC_);
+  virtual ~DebugAddrWriter(){};
   /// Given an address returns an index in .debug_addr.
   /// Adds Address to map.
-  uint32_t getIndexFromAddress(uint64_t Address, uint64_t DWOId);
+  uint32_t getIndexFromAddress(uint64_t Address, uint64_t CUID);
 
   /// Adds {Address, Index} to DWO ID CU.
-  void addIndexAddress(uint64_t Address, uint32_t Index, uint64_t DWOId);
+  void addIndexAddress(uint64_t Address, uint32_t Index, uint64_t CUID);
 
   /// Creates consolidated .debug_addr section, and builds DWOID to offset map.
-  AddressSectionBuffer finalize();
+  virtual AddressSectionBuffer finalize();
 
-  /// Given DWOID returns offset of this CU in to .debug_addr section.
-  uint64_t getOffset(uint64_t DWOId);
+  /// Given DWARFUnit \p Unit returns offset of this CU in to .debug_addr
+  /// section.
+  virtual uint64_t getOffset(DWARFUnit &Unit);
 
   /// Returns False if .debug_addr section was created..
   bool isInitialized() const { return !AddressMaps.empty(); }
 
-private:
+protected:
   class AddressForDWOCU {
   public:
     AddressToIndexMap::iterator find(uint64_t Adddress) {
       return AddressToIndex.find(Adddress);
     }
     AddressToIndexMap::iterator end() { return AddressToIndex.end(); }
     AddressToIndexMap::iterator begin() { return AddressToIndex.begin(); }
 
protected:
   /// Maps DWOID to AddressForDWOCU.
   std::unordered_map<uint64_t, AddressForDWOCU> AddressMaps;
   /// Maps DWOID to offset within .debug_addr section.
   std::unordered_map<uint64_t, uint64_t> DWOIdToOffsetMap;
   /// Mutex used for parallel processing of debug info.
   std::mutex WriterMutex;
 };
 
+class DebugAddrWriterDwarf5 : public DebugAddrWriter {
+public:
+  DebugAddrWriterDwarf5() = delete;
+  DebugAddrWriterDwarf5(BinaryContext *BC) : DebugAddrWriter(BC) {}
+
+  /// Creates consolidated .debug_addr section, and builds DWOID to offset map.
+  virtual AddressSectionBuffer finalize() override;
+  /// Given DWARFUnit \p Unit returns offset of this CU in to .debug_addr
+  /// section.
+  virtual uint64_t getOffset(DWARFUnit &Unit) override;
+};
+
 using DebugStrBufferVector = SmallVector<char, 16>;
 class DebugStrWriter {
 public:
   DebugStrWriter() = delete;
   DebugStrWriter(BinaryContext *Bc) : BC(Bc) { create(); }
   std::unique_ptr<DebugStrBufferVector> finalize() {
     return std::move(StrBuffer);
   }

 class SimpleBinaryPatcher;
 class DebugLocWriter {
 public:
   DebugLocWriter() = delete;
   DebugLocWriter(BinaryContext *BC);
   virtual ~DebugLocWriter(){};
 
   /// Writes out location lists and stores internal patches.
-  virtual void addList(uint64_t AttrOffset, DebugLocationsVector &&LocList);
+  virtual void addList(uint64_t AttrOffset, uint32_t LocListIndex,
+                       DebugLocationsVector &&LocList);
 
   /// Writes out locations in to a local buffer, and adds Debug Info patches.
   virtual void finalize(uint64_t SectionOffset,
                         SimpleBinaryPatcher &DebugInfoPatcher);
 
   /// Return internal buffer.
   virtual std::unique_ptr<DebugBufferVector> getBuffer();
 
+  /// Returns DWARF version.
+  uint8_t getDwarfVersion() const { return DwarfVersion; }
+
   /// Offset of an empty location list.
   static constexpr uint32_t EmptyListOffset = 0;
 
   LocWriterKind getKind() const { return Kind; }
 
   static bool classof(const DebugLocWriter *Writer) {
     return Writer->getKind() == LocWriterKind::DebugLocWriter;
   }
 
 protected:
   std::unique_ptr<DebugBufferVector> LocBuffer;
-
   std::unique_ptr<raw_svector_ostream> LocStream;
   /// Current offset in the section (updated as new entries are written).
   /// Starts with 0 here since this only writes part of a full location lists
   /// section. In the final section, the first 16 bytes are reserved for an
   /// empty list.
   uint32_t SectionOffset{0};
+  uint8_t DwarfVersion{4};
   LocWriterKind Kind{LocWriterKind::DebugLocWriter};
 
 private:
   struct LocListDebugInfoPatchType {
     uint64_t DebugInfoAttrOffset;
     uint64_t LocListOffset;
   };
   using VectorLocListDebugInfoPatchType =
       std::vector<LocListDebugInfoPatchType>;
   /// The list of debug info patches to be made once individual
   /// location list writers have been filled
   VectorLocListDebugInfoPatchType LocListDebugInfoPatches;
 
   using VectorEmptyLocListAttributes = std::vector<uint64_t>;
   /// Contains all the attributes pointing to empty location list.
   VectorEmptyLocListAttributes EmptyAttrLists;
 };
 
 class DebugLoclistWriter : public DebugLocWriter {
 public:
   ~DebugLoclistWriter() {}
   DebugLoclistWriter() = delete;
-  DebugLoclistWriter(BinaryContext *BC, uint64_t DWOId_)
-      : DebugLocWriter(BC), DWOId(DWOId_) {
+  DebugLoclistWriter(BinaryContext *BC, uint64_t CID,
+                     uint32_t LocListsBaseAttrOffset, uint8_t DV, bool SD)
+      : DebugLocWriter(BC), CUID(CID),
+        LocListsBaseAttrOffset(LocListsBaseAttrOffset), IsSplitDwarf(SD) {
     Kind = LocWriterKind::DebugLoclistWriter;
+    DwarfVersion = DV;
     assert(DebugLoclistWriter::AddrWriter &&
            "Please use SetAddressWriter to initialize "
            "DebugAddrWriter before instantiation.");
   }
 
   static void setAddressWriter(DebugAddrWriter *AddrW) { AddrWriter = AddrW; }
 
   /// Stores location lists internally to be written out during finalize phase.
-  virtual void addList(uint64_t AttrOffset,
+  virtual void addList(uint64_t AttrOffset, uint32_t LocListIndex,
                        DebugLocationsVector &&LocList) override;
 
   /// Writes out locations in to a local buffer and applies debug info patches.
   void finalize(uint64_t SectionOffset,
                 SimpleBinaryPatcher &DebugInfoPatcher) override;
 
   /// Returns DWO ID.
-  uint64_t getDWOID() const { return DWOId; }
+  uint64_t getCUID() const { return CUID; }
+
+  LocWriterKind getKind() const { return DebugLocWriter::getKind(); }
 
   static bool classof(const DebugLocWriter *Writer) {
     return Writer->getKind() == LocWriterKind::DebugLoclistWriter;
   }
 
+  bool isSplitDwarf() const { return IsSplitDwarf; }
+
+  constexpr static uint32_t InvalidIndex = UINT32_MAX;
+  constexpr static uint32_t InvalidLocListsBaseAttrOffset = UINT32_MAX;
+
 private:
+  /// Writes out locations in to a local buffer and applies debug info patches.
+  void finalizeDWARFLegacy(uint64_t SectionOffset,
+                           SimpleBinaryPatcher &DebugInfoPatcher);
+
+  /// Writes out locations in to a local buffer and applies debug info patches.
+  void finalizeDWARF5(uint64_t SectionOffset,
+                      SimpleBinaryPatcher &DebugInfoPatcher);
+
   struct LocPatch {
     uint64_t AttrOffset{0};
+    uint32_t Index;
     DebugLocationsVector LocList;
   };
   using LocPatchVec = SmallVector<LocPatch, 4>;
   LocPatchVec Patches;
 
   class Patch {
   public:
     Patch() = delete;
     Patch(uint64_t O, uint64_t A) : Offset(O), Address(A) {}
     uint64_t Offset{0};
     uint64_t Address{0};
   };
   static DebugAddrWriter *AddrWriter;
-  uint64_t DWOId{0};
+  uint64_t CUID{0};
+  uint32_t LocListsBaseAttrOffset{InvalidLocListsBaseAttrOffset};
+  bool IsSplitDwarf{false};
 };
 
 enum class PatcherKind { SimpleBinaryPatcher, DebugInfoBinaryPatcher };
 /// Abstract interface for classes that apply modifications to a binary string.
 class BinaryPatcher {
 public:
   virtual ~BinaryPatcher() {}
   /// Applies modifications to the copy of binary string \p BinaryContents .
private:
 
   /// Line info for the original code. To be merged with tables for new code.
   const DWARFDebugLine::LineTable *InputTable{nullptr};
   std::vector<RowSequence> InputSequences;
 
   /// Raw data representing complete debug line section for the unit.
   StringRef RawData;
 
+  /// DWARF Version
+  uint16_t DwarfVersion;
+
 public:
   /// Emit line info for all units in the binary context.
   static void emit(BinaryContext &BC, MCStreamer &Streamer);
 
   /// Emit the Dwarf file and the line tables for a given CU.
   void emitCU(MCStreamer *MCOS, MCDwarfLineTableParams Params,
               Optional<MCDwarfLineStr> &LineStr, BinaryContext &BC) const;
 
   Expected<unsigned> tryGetFile(StringRef &Directory, StringRef &FileName,
                                 Optional<MD5::MD5Result> Checksum,
                                 Optional<StringRef> Source,
                                 uint16_t DwarfVersion,
                                 unsigned FileNumber = 0) {
     assert(RawData.empty() && "cannot use with raw data");
     return Header.tryGetFile(Directory, FileName, Checksum, Source,
                              DwarfVersion, FileNumber);
   }
 
   /// Return label at the start of the emitted debug line for the unit.
   MCSymbol *getLabel() const { return Header.Label; }
 
   void setLabel(MCSymbol *Label) { Header.Label = Label; }
 
+  /// Sets the root file \p Directory, \p FileName, optional \p CheckSum, and
+  /// optional \p Source.
+  void setRootFile(StringRef Directory, StringRef FileName,
+                   Optional<MD5::MD5Result> Checksum,
+                   Optional<StringRef> Source) {
+    Header.setRootFile(Directory, FileName, Checksum, Source);
+  }
+
   /// Access to MC line info.
   MCLineSection &getMCLineSections() { return MCLineSections; }
 
   /// Add line information using the sequence from the input line \p Table.
   void addLineTableSequence(const DWARFDebugLine::LineTable *Table,
                             uint32_t FirstRow, uint32_t LastRow,
                             uint64_t EndOfSequenceAddress) {
     assert((!InputTable || InputTable == Table) &&
            "expected same table for CU");
     InputTable = Table;
     InputSequences.emplace_back(
         RowSequence{FirstRow, LastRow, EndOfSequenceAddress});
   }
 
   /// Indicate that for the unit we should emit specified contents instead of
   /// generating a new line info table.
   void addRawContents(StringRef DebugLineContents) {
     RawData = DebugLineContents;
   }
+
+  /// Sets DWARF version for this line table.
+  void setDwarfVersion(uint16_t V) { DwarfVersion = V; }
+
+  // Returns DWARF Version for this line table.
+  uint16_t getDwarfVersion() const { return DwarfVersion; }
 };
 
 struct AttrInfo {
   DWARFFormValue V;
   uint64_t Offset;
   uint32_t Size; // Size of the attribute.
 };
 

bolt/include/bolt/Rewrite/DWARFRewriter.h

class DWARFRewriter {
   /// Stores and serializes information that will be put in to the
   /// .debug_addr DWARF section.
   /// Does not do de-duplication.
   std::unique_ptr<DebugStrWriter> StrWriter;
 
   /// .debug_abbrev section writer for the main binary.
   std::unique_ptr<DebugAbbrevWriter> AbbrevWriter;
 
-  using LocWriters =
-      std::unordered_map<uint64_t, std::unique_ptr<DebugLocWriter>>;
+  using LocWriters = std::map<uint64_t, std::unique_ptr<DebugLocWriter>>;
   /// Use a separate location list writer for each compilation unit
   LocWriters LocListWritersByCU;
 
   using DebugAbbrevDWOWriters =
       std::unordered_map<uint64_t, std::unique_ptr<DebugAbbrevWriter>>;
   /// Abbrev section writers for DWOs.
   DebugAbbrevDWOWriters BinaryDWOAbbrevWriters;
 
   using DebugInfoDWOPatchers =
       std::unordered_map<uint64_t, std::unique_ptr<SimpleBinaryPatcher>>;
   /// Binary patchers for DWO debug_info sections.
   DebugInfoDWOPatchers BinaryDWODebugInfoPatchers;
 
   std::mutex LocListDebugInfoPatchesMutex;
 
+  /// DWARFLegacy is all DWARF versions before DWARF 5.
+  enum class DWARFVersion { DWARFLegacy, DWARF5 };
+
   /// Update debug info for all DIEs in \p Unit.
   void updateUnitDebugInfo(DWARFUnit &Unit,
                            DebugInfoBinaryPatcher &DebugInfoPatcher,
                            DebugAbbrevWriter &AbbrevWriter,
                            DebugLocWriter &DebugLocWriter,
+                           DebugRangesSectionWriter &RangesWriter,
                            Optional<uint64_t> RangesBase = None);
 
   /// Patches the binary for an object's address ranges to be updated.
   /// The object can be anything that has associated address ranges via either
   /// DW_AT_low/high_pc or DW_AT_ranges (i.e. functions, lexical blocks, etc).
   /// \p DebugRangesOffset is the offset in .debug_ranges of the object's
   /// new address ranges in the output binary.
   /// \p Unit Compile unit the object belongs to.
   /// \p DIE is the object's DIE in the input binary.
   /// \p RangesBase if present, update \p DIE to use  DW_AT_GNU_ranges_base
   ///    attribute.
   void updateDWARFObjectAddressRanges(const DWARFDie DIE,
                                       uint64_t DebugRangesOffset,
                                       SimpleBinaryPatcher &DebugInfoPatcher,
                                       DebugAbbrevWriter &AbbrevWriter,
                                       Optional<uint64_t> RangesBase = None);
 
   std::unique_ptr<DebugBufferVector>
-  makeFinalLocListsSection(SimpleBinaryPatcher &DebugInfoPatcher);
+  makeFinalLocListsSection(SimpleBinaryPatcher &DebugInfoPatcher,
+                           DWARFVersion Version);
 
   /// Finalize debug sections in the main binary.
   CUOffsetMap finalizeDebugSections(DebugInfoBinaryPatcher &DebugInfoPatcher);
 
   /// Patches the binary for DWARF address ranges (e.g. in functions and lexical
   /// blocks) to be updated.
   void updateDebugAddressRanges();
 

bolt/lib/Core/BinaryContext.cpp

for (auto &Entry : BinaryDataMap) {
     while (P) {
       OS << "  ";
       P = P->getParent();
     }
     OS << *BD << "\n";
   }
 }
 
-Expected<unsigned>
-BinaryContext::getDwarfFile(StringRef Directory, StringRef FileName,
-                            unsigned FileNumber,
-                            Optional<MD5::MD5Result> Checksum,
-                            Optional<StringRef> Source, unsigned CUID) {
+Expected<unsigned> BinaryContext::getDwarfFile(
+    StringRef Directory, StringRef FileName, unsigned FileNumber,
+    Optional<MD5::MD5Result> Checksum, Optional<StringRef> Source,
+    unsigned CUID, unsigned DWARFVersion) {
   DwarfLineTable &Table = DwarfLineTablesCUMap[CUID];
-  return Table.tryGetFile(Directory, FileName, Checksum, Source,
-                          Ctx->getDwarfVersion(), FileNumber);
+  return Table.tryGetFile(Directory, FileName, Checksum, Source, DWARFVersion,
+                          FileNumber);
 }
 
 unsigned BinaryContext::addDebugFilenameToUnit(const uint32_t DestCUID,
                                                const uint32_t SrcCUID,
                                                unsigned FileIndex) {
   DWARFCompileUnit *SrcUnit = DwCtx->getCompileUnitForOffset(SrcCUID);
   const DWARFDebugLine::LineTable *LineTable =
       DwCtx->getLineTableForUnit(SrcUnit);
if (Optional<const char *> DirName = dwarf::toString(
       Dir = *DirName;
     }
   }
   StringRef FileName = "";
   if (Optional<const char *> FName =
           dwarf::toString(FileNames[FileIndex - 1].Name))
     FileName = *FName;
   assert(FileName != "");
-  return cantFail(getDwarfFile(Dir, FileName, 0, None, None, DestCUID));
+  DWARFCompileUnit *DstUnit = DwCtx->getCompileUnitForOffset(DestCUID);
+  return cantFail(getDwarfFile(Dir, FileName, 0, None, None, DestCUID,
+                               DstUnit->getVersion()));
 }
 
 std::vector<BinaryFunction *> BinaryContext::getSortedFunctions() {
   std::vector<BinaryFunction *> SortedFunctions(BinaryFunctions.size());
   std::transform(BinaryFunctions.begin(), BinaryFunctions.end(),
                  SortedFunctions.begin(),
                  [](std::pair<const uint64_t, BinaryFunction> &BFI) {
                    return &BFI.second;
for (const std::unique_ptr<DWARFUnit> &CU : DwCtx->compile_units()) {
     }
     for (DWARFAddressRange &Range : *RangesOrError) {
       // Parts of the debug info could be invalidated due to corresponding code
       // being removed from the binary by the linker. Hence we check if the
       // address is a valid one.
       if (containsAddress(Range.LowPC))
         AllRanges.emplace_back(CURange{Range.LowPC, Range.HighPC, CU.get()});
     }
+
+    ContainsDwarf5 |= CU->getVersion() == 5;
+    ContainsDwarfLegacy |= CU->getVersion() < 5;
   }
 
+  if (ContainsDwarf5 && ContainsDwarfLegacy)
+    llvm::errs() << "BOLT-WARNING: BOLT does not support mix mode binary with "
+                    "DWARF5 and DWARF{2,3,4}.\n";
+
   std::sort(AllRanges.begin(), AllRanges.end());
   for (auto &KV : BinaryFunctions) {
     const uint64_t FunctionAddress = KV.first;
     BinaryFunction &Function = KV.second;
 
     auto It = std::partition_point(
         AllRanges.begin(), AllRanges.end(),
         [=](CURange R) { return R.HighPC <= FunctionAddress; });
if (opts::Verbosity >= 1) {
     outs() << "BOLT-INFO: " << ProcessedCUs.size() << " out of "
            << DwCtx->getNumCompileUnits() << " CUs will be updated\n";
   }
 
   // Populate MCContext with DWARF files from all units.
   StringRef GlobalPrefix = AsmInfo->getPrivateGlobalPrefix();
   for (const std::unique_ptr<DWARFUnit> &CU : DwCtx->compile_units()) {
     const uint64_t CUID = CU->getOffset();
-    getDwarfLineTable(CUID).setLabel(Ctx->getOrCreateSymbol(
+    DwarfLineTable &BinaryLineTable = getDwarfLineTable(CUID);
+    BinaryLineTable.setLabel(Ctx->getOrCreateSymbol(
         GlobalPrefix + "line_table_start" + Twine(CUID)));
 
     if (!ProcessedCUs.count(CU.get()))
       continue;
 
     const DWARFDebugLine::LineTable *LineTable =
         DwCtx->getLineTableForUnit(CU.get());
     const std::vector<DWARFDebugLine::FileNameEntry> &FileNames =
         LineTable->Prologue.FileNames;
 
+    uint16_t DwarfVersion = LineTable->Prologue.getVersion();
+    if (DwarfVersion == 5) {
+      Optional<MD5::MD5Result> Checksum = None;
+      if (LineTable->Prologue.ContentTypes.HasMD5)
+        Checksum = LineTable->Prologue.FileNames[0].Checksum;
+      BinaryLineTable.setRootFile(
+          CU->getCompilationDir(),
+          dwarf::toString(CU->getUnitDIE().find(dwarf::DW_AT_name), nullptr),
+          Checksum, None);
+    }
+
+    BinaryLineTable.setDwarfVersion(DwarfVersion);
+
     // Assign a unique label to every line table, one per CU.
     // Make sure empty debug line tables are registered too.
     if (FileNames.empty()) {
-      cantFail(getDwarfFile("", "<unknown>", 0, None, None, CUID));
+      cantFail(
+          getDwarfFile("", "<unknown>", 0, None, None, CUID, DwarfVersion));
       continue;
     }
+    const uint32_t Offset = DwarfVersion < 5 ? 1 : 0;
     for (size_t I = 0, Size = FileNames.size(); I != Size; ++I) {
       // Dir indexes start at 1, as DWARF file numbers, and a dir index 0
       // means empty dir.
       StringRef Dir = "";
-      if (FileNames[I].DirIdx != 0)
+      if (FileNames[I].DirIdx != 0 || DwarfVersion == 5)
         if (Optional<const char *> DirName = dwarf::toString(
                 LineTable->Prologue
-                    .IncludeDirectories[FileNames[I].DirIdx - 1]))
+                    .IncludeDirectories[FileNames[I].DirIdx - Offset]))
           Dir = *DirName;
       StringRef FileName = "";
       if (Optional<const char *> FName = dwarf::toString(FileNames[I].Name))
         FileName = *FName;
       assert(FileName != "");
-      cantFail(getDwarfFile(Dir, FileName, 0, None, None, CUID));
+      Optional<MD5::MD5Result> Checksum = None;
+      if (DwarfVersion == 5 && LineTable->Prologue.ContentTypes.HasMD5)
+        Checksum = LineTable->Prologue.FileNames[I].Checksum;
+      cantFail(
+          getDwarfFile(Dir, FileName, 0, Checksum, None, CUID, DwarfVersion));
     }
   }
 
   preprocessDWODebugInfo();
 }
 
 bool BinaryContext::shouldEmit(const BinaryFunction &Function) const {
   if (Function.isPseudo())

bolt/lib/Core/DebugData.cpp

 //===- bolt/Core/DebugData.cpp - Debugging information handling -----------===//
 //
 // 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 file implements functions and classes for handling debug info.
 //
 //===----------------------------------------------------------------------===//
 
 #include "bolt/Core/DebugData.h"
 #include "bolt/Core/BinaryContext.h"
+#include "bolt/Rewrite/RewriteInstance.h"
 #include "bolt/Utils/Utils.h"
 #include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugAddr.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCObjectStreamer.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/EndianStream.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Support/SHA1.h"
 #include <algorithm>

 
 DebugRangesSectionWriter::DebugRangesSectionWriter() {
   RangesBuffer = std::make_unique<DebugBufferVector>();
   RangesStream = std::make_unique<raw_svector_ostream>(*RangesBuffer);
 
   // Add an empty range as the first entry;
   SectionOffset +=
       writeAddressRanges(*RangesStream.get(), DebugAddressRangesVector{});
+  Kind = RangesWriterKind::DebugRangesWriter;
 }
 
 uint64_t DebugRangesSectionWriter::addRanges(
     DebugAddressRangesVector &&Ranges,
     std::map<DebugAddressRangesVector, uint64_t> &CachedRanges) {
   if (Ranges.empty())
     return getEmptyRangesOffset();
 
DebugRangesSectionWriter::addRanges(const DebugAddressRangesVector &Ranges) {
   return EntryOffset;
 }
 
 uint64_t DebugRangesSectionWriter::getSectionOffset() {
   std::lock_guard<std::mutex> Lock(WriterMutex);
   return SectionOffset;
 }
 
+DebugAddrWriter *DebugRangeListsSectionWriter::AddrWriter = nullptr;
+
+uint64_t DebugRangeListsSectionWriter::addRanges(
+    DebugAddressRangesVector &&Ranges,
+    std::map<DebugAddressRangesVector, uint64_t> &CachedRanges) {
+  return addRanges(Ranges);
+}
+
+struct LocListsRangelistsHeader {
+  UnitLengthType UnitLength; // Size of loclist entris section, not including
+                             // size of header.
+  VersionType Version;
+  AddressSizeType AddressSize;
+  SegmentSelectorType SegmentSelector;
+  OffsetEntryCountType OffsetEntryCount;
+};
+
+static std::unique_ptr<DebugBufferVector>
+getDWARF5Header(const LocListsRangelistsHeader &Header) {
+  std::unique_ptr<DebugBufferVector> HeaderBuffer =
+      std::make_unique<DebugBufferVector>();
+  std::unique_ptr<raw_svector_ostream> HeaderStream =
+      std::make_unique<raw_svector_ostream>(*HeaderBuffer);
+
+  // 7.29 length of the set of entries for this compilation unit, not including
+  // the length field itself
+  const uint32_t HeaderSize =
+      getDWARF5RngListLocListHeaderSize() - sizeof(UnitLengthType);
+
+  support::endian::write(*HeaderStream, Header.UnitLength + HeaderSize,
+                         support::little);
+  support::endian::write(*HeaderStream, Header.Version, support::little);
+  support::endian::write(*HeaderStream, Header.AddressSize, support::little);
+  support::endian::write(*HeaderStream, Header.SegmentSelector,
+                         support::little);
+  support::endian::write(*HeaderStream, Header.OffsetEntryCount,
+                         support::little);
+  return HeaderBuffer;
+}
+
+uint64_t DebugRangeListsSectionWriter::addRanges(
+    const DebugAddressRangesVector &Ranges) {
+  std::lock_guard<std::mutex> Lock(WriterMutex);
+
+  RangeEntries.push_back(CurrentOffset);
+  for (const DebugAddressRange &Range : Ranges) {
+    support::endian::write(*CUBodyStream,
+                           static_cast<uint8_t>(dwarf::DW_RLE_startx_length),
+                           support::little);
+    const uint32_t Index = AddrWriter->getIndexFromAddress(Range.LowPC, CUID);
+    encodeULEB128(Index, *CUBodyStream);
+    encodeULEB128(Range.HighPC - Range.LowPC, *CUBodyStream);
+  }
+  support::endian::write(*CUBodyStream,
+                         static_cast<uint8_t>(dwarf::DW_RLE_end_of_list),
+                         support::little);
+  CurrentOffset = CUBodyBuffer->size();
+  return RangeEntries.size() - 1;
+}
+
+void DebugRangeListsSectionWriter::finalizeSection() {
+  std::unique_ptr<DebugBufferVector> CUArrayBuffer =
+      std::make_unique<DebugBufferVector>();
+  std::unique_ptr<raw_svector_ostream> CUArrayStream =
+      std::make_unique<raw_svector_ostream>(*CUArrayBuffer);
+  constexpr uint32_t SizeOfArrayEntry = 4;
+  const uint32_t SizeOfArraySection = RangeEntries.size() * SizeOfArrayEntry;
+  for (uint32_t Offset : RangeEntries)
+    support::endian::write(*CUArrayStream, Offset + SizeOfArraySection,
+                           support::little);
+
+  std::unique_ptr<DebugBufferVector> Header = getDWARF5Header(
+      {static_cast<uint32_t>(SizeOfArraySection + CUBodyBuffer.get()->size()),
+       5, 8, 0, static_cast<uint32_t>(RangeEntries.size())});
+  *RangesStream << *Header;
+  *RangesStream << *CUArrayBuffer;
+  *RangesStream << *CUBodyBuffer;
+  SectionOffset = RangesBuffer->size();
+}
+
+void DebugRangeListsSectionWriter::initSection(uint64_t CUId_) {
+  CUBodyBuffer = std::make_unique<DebugBufferVector>();
+  CUBodyStream = std::make_unique<raw_svector_ostream>(*CUBodyBuffer);
+  RangeEntries.clear();
+  CurrentOffset = 0;
+  CUID = CUId_;
+}
+
 void DebugARangesSectionWriter::addCURanges(uint64_t CUOffset,
                                             DebugAddressRangesVector &&Ranges) {
   std::lock_guard<std::mutex> Lock(CUAddressRangesMutex);
   CUAddressRanges.emplace(CUOffset, std::move(Ranges));
 }
 
 void DebugARangesSectionWriter::writeARangesSection(
     raw_svector_ostream &RangesStream, const CUOffsetMap &CUMap) const {
void DebugAddrWriter::AddressForDWOCU::dump() {
   // Sorting address in increasing order of indices.
   std::sort(SortedMap.begin(), SortedMap.end(),
             [](const IndexAddressPair &A, const IndexAddressPair &B) {
               return A.first < B.first;
             });
   for (auto &Pair : SortedMap)
     dbgs() << Twine::utohexstr(Pair.second) << "\t" << Pair.first << "\n";
 }
-uint32_t DebugAddrWriter::getIndexFromAddress(uint64_t Address,
-                                              uint64_t DWOId) {
+uint32_t DebugAddrWriter::getIndexFromAddress(uint64_t Address, uint64_t CUID) {
   std::lock_guard<std::mutex> Lock(WriterMutex);
-  if (!AddressMaps.count(DWOId))
-    AddressMaps[DWOId] = AddressForDWOCU();
+  if (!AddressMaps.count(CUID))
+    AddressMaps[CUID] = AddressForDWOCU();
 
-  AddressForDWOCU &Map = AddressMaps[DWOId];
+  AddressForDWOCU &Map = AddressMaps[CUID];
   auto Entry = Map.find(Address);
   if (Entry == Map.end()) {
     auto Index = Map.getNextIndex();
     Entry = Map.insert(Address, Index).first;
   }
   return Entry->second;
 }
 
 // Case1) Address is not in map insert in to AddresToIndex and IndexToAddres
 // Case2) Address is in the map but Index is higher or equal. Need to update
 // IndexToAddrss. Case3) Address is in the map but Index is lower. Need to
 // update AddressToIndex and IndexToAddress
 void DebugAddrWriter::addIndexAddress(uint64_t Address, uint32_t Index,
-                                      uint64_t DWOId) {
+                                      uint64_t CUID) {
   std::lock_guard<std::mutex> Lock(WriterMutex);
-  AddressForDWOCU &Map = AddressMaps[DWOId];
+  AddressForDWOCU &Map = AddressMaps[CUID];
   auto Entry = Map.find(Address);
   if (Entry != Map.end()) {
     if (Entry->second > Index)
       Map.updateAddressToIndex(Address, Index);
     Map.updateIndexToAddrss(Address, Index);
   } else {
     Map.insert(Address, Index);
   }
 }
 
 AddressSectionBuffer DebugAddrWriter::finalize() {
   // Need to layout all sections within .debug_addr
   // Within each section sort Address by index.
   AddressSectionBuffer Buffer;
   raw_svector_ostream AddressStream(Buffer);
   for (std::unique_ptr<DWARFUnit> &CU : BC->DwCtx->compile_units()) {
     Optional<uint64_t> DWOId = CU->getDWOId();
     // Handling the case wehre debug information is a mix of Debug fission and
     // monolitic.
     if (!DWOId)
       continue;
     auto AM = AddressMaps.find(*DWOId);
+    assert(AM != AddressMaps.end() && "Address Map not found.");
     // Adding to map even if it did not contribute to .debug_addr.
     // The Skeleton CU will still have DW_AT_GNU_addr_base.
     DWOIdToOffsetMap[*DWOId] = Buffer.size();
     // If does not exist this CUs DWO section didn't contribute to .debug_addr.
     if (AM == AddressMaps.end())
       continue;
     std::vector<IndexAddressPair> SortedMap(AM->second.indexToAddressBegin(),
                                             AM->second.indexToAdddessEnd());
for (const IndexAddressPair &Val : SortedMap) {
       while (Val.first > Counter)
         WriteAddress(0);
       WriteAddress(Val.second);
     }
   }
 
   return Buffer;
 }
+AddressSectionBuffer DebugAddrWriterDwarf5::finalize() {
+  // Need to layout all sections within .debug_addr
+  // Within each section sort Address by index.
+  AddressSectionBuffer Buffer;
+  raw_svector_ostream AddressStream(Buffer);
+  const endianness Endian =
+      BC->DwCtx->isLittleEndian() ? support::little : support::big;
+  const DWARFSection &AddrSec = BC->DwCtx->getDWARFObj().getAddrSection();
+  DWARFDataExtractor AddrData(BC->DwCtx->getDWARFObj(), AddrSec, Endian, 0);
+  DWARFDebugAddrTable AddrTable;
+  DIDumpOptions DumpOpts;
+  constexpr uint32_t HeaderSize = 8;
+  for (std::unique_ptr<DWARFUnit> &CU : BC->DwCtx->compile_units()) {
+    const uint64_t CUID = CU->getOffset();
+    const uint8_t AddrSize = CU->getAddressByteSize();
+    auto Iter = AddressMaps.find(CUID);
+    // A case where CU has entry in .debug_addr, but we don't modify addresses
+    // for it.
+    if (Iter == AddressMaps.end()) {
+      Iter = AddressMaps.insert({CUID, AddressForDWOCU()}).first;
+      Optional<uint64_t> BaseOffset = CU->getAddrOffsetSectionBase();
+      if (!BaseOffset)
+        continue;
+      // Address base offset is to the first entry.
+      // The size of header is 8 bytes.
+      uint64_t Offset = *BaseOffset - HeaderSize;
+      if (Error Err = AddrTable.extract(AddrData, &Offset, 5, AddrSize,
+                                        DumpOpts.WarningHandler)) {
+        DumpOpts.RecoverableErrorHandler(std::move(Err));
+        continue;
+      }
+      uint32_t Index = 0;
+      for (uint64_t Addr : AddrTable.getAddressEntries())
+        Iter->second.insert(Addr, Index++);
+    }
+
+    DWOIdToOffsetMap[CUID] = Buffer.size() + HeaderSize;
+
+    std::vector<IndexAddressPair> SortedMap(Iter->second.indexToAddressBegin(),
+                                            Iter->second.indexToAdddessEnd());
+    // Sorting address in increasing order of indices.
+    std::sort(SortedMap.begin(), SortedMap.end(),
+              [](const IndexAddressPair &A, const IndexAddressPair &B) {
+                return A.first < B.first;
+              });
+    // Writing out Header
+    const uint32_t Length = SortedMap.size() * AddrSize + 4;
+    support::endian::write(AddressStream, Length, Endian);
+    support::endian::write(AddressStream, static_cast<uint16_t>(5), Endian);
+    support::endian::write(AddressStream, static_cast<uint8_t>(AddrSize),
+                           Endian);
+    support::endian::write(AddressStream, static_cast<uint8_t>(0), Endian);
+
+    uint32_t Counter = 0;
+    auto writeAddress = [&](uint64_t Address) -> void {
+      ++Counter;
+      switch (AddrSize) {
+      default:
+        llvm_unreachable("Address Size is invalid.");
+        break;
+      case 4:
+        support::endian::write(AddressStream, static_cast<uint32_t>(Address),
+                               Endian);
+        break;
+      case 8:
+        support::endian::write(AddressStream, Address, Endian);
+        break;
+      }
+    };
+
+    for (const IndexAddressPair &Val : SortedMap) {
+      while (Val.first > Counter)
+        writeAddress(0);
+      writeAddress(Val.second);
+    }
+  }
+
+  return Buffer;
+}
 
-uint64_t DebugAddrWriter::getOffset(uint64_t DWOId) {
-  auto Iter = DWOIdToOffsetMap.find(DWOId);
+uint64_t DebugAddrWriter::getOffset(DWARFUnit &Unit) {
+  Optional<uint64_t> DWOId = Unit.getDWOId();
+  assert(DWOId && "Can't get offset, not a skeleton CU.");
+  auto Iter = DWOIdToOffsetMap.find(*DWOId);
+  assert(Iter != DWOIdToOffsetMap.end() &&
+         "Offset in to.debug_addr was not found for DWO ID.");
+  return Iter->second;
+}
+
+uint64_t DebugAddrWriterDwarf5::getOffset(DWARFUnit &Unit) {
+  auto Iter = DWOIdToOffsetMap.find(Unit.getOffset());
   assert(Iter != DWOIdToOffsetMap.end() &&
          "Offset in to.debug_addr was not found for DWO ID.");
   return Iter->second;
 }
 
 DebugLocWriter::DebugLocWriter(BinaryContext *BC) {
   LocBuffer = std::make_unique<DebugBufferVector>();
   LocStream = std::make_unique<raw_svector_ostream>(*LocBuffer);
 }
 
-void DebugLocWriter::addList(uint64_t AttrOffset,
+void DebugLocWriter::addList(uint64_t AttrOffset, uint32_t LocListIndex,
                              DebugLocationsVector &&LocList) {
   if (LocList.empty()) {
     EmptyAttrLists.push_back(AttrOffset);
     return;
   }
   // Since there is a separate DebugLocWriter for each thread,
   // we don't need a lock to read the SectionOffset and update it.
   const uint32_t EntryOffset = SectionOffset;
*LocStream << StringRef(reinterpret_cast<const char *>(Entry.Expr.data()),
                             Entry.Expr.size());
     SectionOffset += 2 * 8 + 2 + Entry.Expr.size();
   }
   LocStream->write_zeros(16);
   SectionOffset += 16;
   LocListDebugInfoPatches.push_back({AttrOffset, EntryOffset});
 }
 
-void DebugLoclistWriter::addList(uint64_t AttrOffset,
+void DebugLoclistWriter::addList(uint64_t AttrOffset, uint32_t LocListIndex,
                                  DebugLocationsVector &&LocList) {
-  Patches.push_back({AttrOffset, std::move(LocList)});
+  Patches.push_back({AttrOffset, LocListIndex, std::move(LocList)});
 }
 
 std::unique_ptr<DebugBufferVector> DebugLocWriter::getBuffer() {
   return std::move(LocBuffer);
 }
 
 // DWARF 4: 2.6.2
 void DebugLocWriter::finalize(uint64_t SectionOffset,
                               SimpleBinaryPatcher &DebugInfoPatcher) {
   for (const auto LocListDebugInfoPatchType : LocListDebugInfoPatches) {
     uint64_t Offset = SectionOffset + LocListDebugInfoPatchType.LocListOffset;
     DebugInfoPatcher.addLE32Patch(LocListDebugInfoPatchType.DebugInfoAttrOffset,
                                   Offset);
   }
 
   for (uint64_t DebugInfoAttrOffset : EmptyAttrLists)
     DebugInfoPatcher.addLE32Patch(DebugInfoAttrOffset,
                                   DebugLocWriter::EmptyListOffset);
 }
 
-void DebugLoclistWriter::finalize(uint64_t SectionOffset,
+static void writeEmptyListDwarf5(raw_svector_ostream &Stream) {
+  support::endian::write(Stream, static_cast<uint32_t>(4), support::little);
+  support::endian::write(Stream, static_cast<uint8_t>(dwarf::DW_LLE_start_end),
+                         support::little);
+
+  const char Zeroes[16] = {0};
+  Stream << StringRef(Zeroes, 16);
+  encodeULEB128(0, Stream);
+  support::endian::write(
+      Stream, static_cast<uint8_t>(dwarf::DW_LLE_end_of_list), support::little);
+}
+
+void DebugLoclistWriter::finalizeDWARF5(uint64_t SectionOffset,
                                         SimpleBinaryPatcher &DebugInfoPatcher) {
+
+  std::unique_ptr<DebugBufferVector> LocArrayBuffer =
+      std::make_unique<DebugBufferVector>();
+  std::unique_ptr<raw_svector_ostream> LocArrayStream =
+      std::make_unique<raw_svector_ostream>(*LocArrayBuffer);
+  std::unique_ptr<DebugBufferVector> LocBodyBuffer =
+      std::make_unique<DebugBufferVector>();
+  std::unique_ptr<raw_svector_ostream> LocBodyStream =
+      std::make_unique<raw_svector_ostream>(*LocBodyBuffer);
+
+  const uint32_t SizeOfArraySection = Patches.size() * sizeof(uint32_t);
+  std::sort(Patches.begin(), Patches.end(),
+            [](const LocPatch &P1, const LocPatch &P2) -> bool {
+              return P1.Index < P2.Index;
+            });
+
+  if (LocListsBaseAttrOffset != InvalidLocListsBaseAttrOffset)
+    DebugInfoPatcher.addLE32Patch(LocListsBaseAttrOffset,
+                                  SectionOffset +
+                                      getDWARF5RngListLocListHeaderSize());
+
+  uint32_t Index{0};
+  for (LocPatch &Patch : Patches) {
+    const uint32_t EntryOffset = LocBodyBuffer->size();
+    if (Patch.LocList.empty()) {
+      if (Patch.Index == DebugLoclistWriter::InvalidIndex)
+        DebugInfoPatcher.addLE32Patch(Patch.AttrOffset, EntryOffset);
+
+      writeEmptyListDwarf5(*LocBodyStream);
+      continue;
+    }
+
+    assert(Patch.Index == DebugLoclistWriter::InvalidIndex ||
+           Patch.Index == Index++ && "Gap in LocList Index Array.");
+
+    std::vector<uint64_t> OffsetsArray;
+    for (const DebugLocationEntry &Entry : Patch.LocList) {
+      support::endian::write(*LocBodyStream,
+                             static_cast<uint8_t>(dwarf::DW_LLE_startx_length),
+                             support::little);
+      const uint32_t Index = AddrWriter->getIndexFromAddress(Entry.LowPC, CUID);
+      encodeULEB128(Index, *LocBodyStream);
+      encodeULEB128(Entry.HighPC - Entry.LowPC, *LocBodyStream);
+      encodeULEB128(Entry.Expr.size(), *LocBodyStream);
+      *LocBodyStream << StringRef(
+          reinterpret_cast<const char *>(Entry.Expr.data()), Entry.Expr.size());
+    }
+    support::endian::write(*LocBodyStream,
+                           static_cast<uint8_t>(dwarf::DW_LLE_end_of_list),
+                           support::little);
+
+    // Write out IndexArray
+    support::endian::write(
+        *LocArrayStream,
+        static_cast<uint32_t>(SizeOfArraySection + EntryOffset),
+        support::little);
+    // Don't need to patch Index since we are re-using them.
+    if (Patch.Index == DebugLoclistWriter::InvalidIndex)
+      DebugInfoPatcher.addLE32Patch(Patch.AttrOffset, EntryOffset);
+    clearList(Patch.LocList);
+  }
+  if (!Patches.empty()) {
+    std::unique_ptr<DebugBufferVector> Header =
+        getDWARF5Header({static_cast<uint32_t>(SizeOfArraySection +
+                                               LocBodyBuffer.get()->size()),
+                         5, 8, 0, static_cast<uint32_t>(Patches.size())});
+    *LocStream << *Header;
+    *LocStream << *LocArrayBuffer;
+    *LocStream << *LocBodyBuffer;
+  }
+  clearList(Patches);
+}
+
+void DebugLoclistWriter::finalizeDWARFLegacy(
+    uint64_t SectionOffset, SimpleBinaryPatcher &DebugInfoPatcher) {
   for (LocPatch &Patch : Patches) {
     if (Patch.LocList.empty()) {
       DebugInfoPatcher.addLE32Patch(Patch.AttrOffset,
                                     DebugLocWriter::EmptyListOffset);
       continue;
     }
     const uint32_t EntryOffset = LocBuffer->size();
     for (const DebugLocationEntry &Entry : Patch.LocList) {
       support::endian::write(*LocStream,
                              static_cast<uint8_t>(dwarf::DW_LLE_startx_length),
                              support::little);
-      uint32_t Index = AddrWriter->getIndexFromAddress(Entry.LowPC, DWOId);
+      const uint32_t Index = AddrWriter->getIndexFromAddress(Entry.LowPC, CUID);
       encodeULEB128(Index, *LocStream);
 
       // TODO: Support DWARF5
       support::endian::write(*LocStream,
                              static_cast<uint32_t>(Entry.HighPC - Entry.LowPC),
                              support::little);
       support::endian::write(*LocStream,
                              static_cast<uint16_t>(Entry.Expr.size()),
                              support::little);
       *LocStream << StringRef(reinterpret_cast<const char *>(Entry.Expr.data()),
                               Entry.Expr.size());
     }
     support::endian::write(*LocStream,
                            static_cast<uint8_t>(dwarf::DW_LLE_end_of_list),
                            support::little);
     DebugInfoPatcher.addLE32Patch(Patch.AttrOffset, EntryOffset);
     clearList(Patch.LocList);
   }
   clearList(Patches);
 }
 
+void DebugLoclistWriter::finalize(uint64_t SectionOffset,
+                                  SimpleBinaryPatcher &DebugInfoPatcher) {
+  if (DwarfVersion < 5)
+    finalizeDWARFLegacy(SectionOffset, DebugInfoPatcher);
+  else
+    finalizeDWARF5(SectionOffset, DebugInfoPatcher);
+}
+
 DebugAddrWriter *DebugLoclistWriter::AddrWriter = nullptr;
 
 void DebugInfoBinaryPatcher::addUnitBaseOffsetLabel(uint64_t Offset) {
   Offset -= DWPUnitOffset;
   std::lock_guard<std::mutex> Lock(WriterMutex);
   DebugPatches.emplace_back(new DWARFUnitOffsetBaseLabel(Offset));
 }
 
if (FileNum != LineEntry.getFileNum()) {
       MCOS->emitULEB128IntValue(FileNum);
     }
     if (Column != LineEntry.getColumn()) {
       Column = LineEntry.getColumn();
       MCOS->emitInt8(dwarf::DW_LNS_set_column);
       MCOS->emitULEB128IntValue(Column);
     }
     if (Discriminator != LineEntry.getDiscriminator() &&
-        MCOS->getContext().getDwarfVersion() >= 4) {
+        MCOS->getContext().getDwarfVersion() >= 2) {
       Discriminator = LineEntry.getDiscriminator();
       unsigned Size = getULEB128Size(Discriminator);
       MCOS->emitInt8(dwarf::DW_LNS_extended_op);
       MCOS->emitULEB128IntValue(Size + 1);
       MCOS->emitInt8(dwarf::DW_LNE_set_discriminator);
       MCOS->emitULEB128IntValue(Discriminator);
     }
     if (Isa != LineEntry.getIsa()) {
void DwarfLineTable::emitCU(MCStreamer *MCOS, MCDwarfLineTableParams Params,
   // Emit line tables for the original code.
   emitBinaryDwarfLineTable(MCOS, Params, InputTable, InputSequences);
 
   // This is the end of the section, so set the value of the symbol at the end
   // of this section (that was used in a previous expression).
   MCOS->emitLabel(LineEndSym);
 }
 
+// Helper function to parse .debug_line_str, and populate one we are using.
+// For functions that we do not modify we output them as raw data.
+// Re-constructing .debug_line_str so that offsets are correct for those
+// debut line tables.
+// Bonus is that when we output a final binary we can re-use .debug_line_str
+// section. So we don't have to do the SHF_ALLOC trick we did with
+// .debug_line.
+static void parseAndPopulateDebugLineStr(BinarySection &LineStrSection,
+                                         MCDwarfLineStr &LineStr,
+                                         BinaryContext &BC,
+                                         MCStreamer &Streamer) {
+  DataExtractor StrData(LineStrSection.getContents(),
+                        BC.DwCtx->isLittleEndian(), 0);
+  uint64_t Offset = 0;
+  while (StrData.isValidOffset(Offset)) {
+    Error Err = Error::success();
+    const char *CStr = StrData.getCStr(&Offset, &Err);
+    if (Err) {
+      errs() << "BOLT-ERROR: could not extract string from .debug_line_str";
+      continue;
+    }
+    LineStr.emitRef(&Streamer, CStr);
+  }
+}
+
 void DwarfLineTable::emit(BinaryContext &BC, MCStreamer &Streamer) {
   MCAssembler &Assembler =
       static_cast<MCObjectStreamer *>(&Streamer)->getAssembler();
 
   MCDwarfLineTableParams Params = Assembler.getDWARFLinetableParams();
 
   auto &LineTables = BC.getDwarfLineTables();
 
   // Bail out early so we don't switch to the debug_line section needlessly and
   // in doing so create an unnecessary (if empty) section.
   if (LineTables.empty())
     return;
-
   // In a v5 non-split line table, put the strings in a separate section.
   Optional<MCDwarfLineStr> LineStr(None);
-  if (BC.Ctx->getDwarfVersion() >= 5)
+  ErrorOr<BinarySection &> LineStrSection =
+      BC.getUniqueSectionByName(".debug_line_str");
+  // Some versions of GCC output DWARF5 .debug_info, but DWARF4 or lower
+  // .debug_line
+  if (LineStrSection) {
     LineStr = MCDwarfLineStr(*BC.Ctx);
+    parseAndPopulateDebugLineStr(*LineStrSection, *LineStr, BC, Streamer);
+  }
 
   // Switch to the section where the table will be emitted into.
   Streamer.SwitchSection(BC.MOFI->getDwarfLineSection());
 
+  const uint16_t DwarfVersion = BC.Ctx->getDwarfVersion();
   // Handle the rest of the Compile Units.
   for (auto &CUIDTablePair : LineTables) {
+    Streamer.getContext().setDwarfVersion(
+        CUIDTablePair.second.getDwarfVersion());
     CUIDTablePair.second.emitCU(&Streamer, Params, LineStr, BC);
   }
+
+  // Resetting DWARF version for rest of the flow.
+  BC.Ctx->setDwarfVersion(DwarfVersion);
+
+  // Still need to write the section out for the ExecutionEngine, and temp in
+  // memory object we are constructing.
+  if (LineStr) {
+    LineStr->emitSection(&Streamer);
+    SmallString<0> Data = LineStr->getFinalizedData();
+    BC.registerOrUpdateNoteSection(".debug_line_str", copyByteArray(Data.str()),
+                                   Data.size());
+  }
 }
 
 } // namespace bolt
 } // namespace llvm

bolt/lib/Rewrite/DWARFRewriter.cpp

 #include "llvm/MC/MCStreamer.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/LEB128.h"
 #include "llvm/Support/ThreadPool.h"
 #include "llvm/Support/ToolOutputFile.h"
 #include <algorithm>
 #include <cstdint>
 #include <string>
 #include <unordered_map>
 
 #undef  DEBUG_TYPE
const DWARFAbbreviationDeclaration *AbbrevDecl =
       DIE.getAbbreviationDeclarationPtr();
   if (!AbbrevDecl)
     return None;
   Optional<uint32_t> Index = AbbrevDecl->findAttributeIndex(Attr);
   if (!Index)
     return None;
   return findAttributeInfo(DIE, AbbrevDecl, *Index);
 }
+
+/// Finds attributes FormValue and Offset.
+///
+/// \param DIE die to look up in.
+/// \param Attrs finds the first attribute that matches and extracts it.
+/// \return an optional AttrInfo with DWARFFormValue and Offset.
+Optional<AttrInfo> findAttributeInfo(const DWARFDie DIE,
+                                     std::vector<dwarf::Attribute> Attrs) {
+  for (dwarf::Attribute &Attr : Attrs)
+    if (Optional<AttrInfo> Info = findAttributeInfo(DIE, Attr))
+      return Info;
+  return None;
+}
 } // namespace bolt
 } // namespace llvm
 
 using namespace llvm;
 using namespace llvm::support::endian;
 using namespace object;
 using namespace bolt;
 
void DWARFRewriter::updateDebugInfo() {
   ErrorOr<BinarySection &> DebugInfo = BC.getUniqueSectionByName(".debug_info");
   if (!DebugInfo)
     return;
 
   auto *DebugInfoPatcher =
       static_cast<DebugInfoBinaryPatcher *>(DebugInfo->getPatcher());
 
   ARangesSectionWriter = std::make_unique<DebugARangesSectionWriter>();
-  RangesSectionWriter = std::make_unique<DebugRangesSectionWriter>();
   StrWriter = std::make_unique<DebugStrWriter>(&BC);
   AbbrevWriter = std::make_unique<DebugAbbrevWriter>(*BC.DwCtx);
 
+  if (BC.isDWARF5Used()) {
+    // Disabling none deterministic mode for dwarf5, to keep implementation
+    // simpler.
+    opts::DeterministicDebugInfo = true;
+    AddrWriter = std::make_unique<DebugAddrWriterDwarf5>(&BC);
+    RangesSectionWriter = std::make_unique<DebugRangeListsSectionWriter>();
+    DebugRangeListsSectionWriter::setAddressWriter(AddrWriter.get());
+  } else {
     AddrWriter = std::make_unique<DebugAddrWriter>(&BC);
-  DebugLoclistWriter::setAddressWriter(AddrWriter.get());
-
-  uint64_t NumCUs = BC.DwCtx->getNumCompileUnits();
-  if ((opts::NoThreads || opts::DeterministicDebugInfo) &&
-      BC.getNumDWOCUs() == 0) {
-    // Use single entry for efficiency when running single-threaded
-    NumCUs = 1;
+    RangesSectionWriter = std::make_unique<DebugRangesSectionWriter>();
   }
 
-  LocListWritersByCU.reserve(NumCUs);
+  DebugLoclistWriter::setAddressWriter(AddrWriter.get());
 
-  for (size_t CUIndex = 0; CUIndex < NumCUs; ++CUIndex)
+  size_t CUIndex = 0;
+  for (std::unique_ptr<DWARFUnit> &CU : BC.DwCtx->compile_units()) {
+    if (CU->getVersion() == 5) {
+      uint32_t AttrInfoOffset =
+          DebugLoclistWriter::InvalidLocListsBaseAttrOffset;
+      if (Optional<AttrInfo> AttrInfoVal =
+              findAttributeInfo(CU->getUnitDIE(), dwarf::DW_AT_loclists_base))
+        AttrInfoOffset = AttrInfoVal->Offset;
+
+      LocListWritersByCU[CUIndex] = std::make_unique<DebugLoclistWriter>(
+          &BC, CU->isDWOUnit() ? *CU->getDWOId() : CU->getOffset(),
+          AttrInfoOffset, 5, false);
+    } else {
       LocListWritersByCU[CUIndex] = std::make_unique<DebugLocWriter>(&BC);
+    }
+    ++CUIndex;
+  }
 
   // Unordered maps to handle name collision if output DWO directory is
   // specified.
   std::unordered_map<std::string, uint32_t> NameToIndexMap;
   std::unordered_map<uint64_t, std::string> DWOIdToName;
   std::mutex AccessMutex;
 
   auto updateDWONameCompDir = [&](DWARFUnit &Unit) -> void {
     const DWARFDie &DIE = Unit.getUnitDIE();
-    Optional<AttrInfo> AttrInfoVal =
-        findAttributeInfo(DIE, dwarf::DW_AT_GNU_dwo_name);
+    Optional<AttrInfo> AttrInfoVal = findAttributeInfo(
+        DIE, {dwarf::DW_AT_dwo_name, dwarf::DW_AT_GNU_dwo_name});
     (void)AttrInfoVal;
     assert(AttrInfoVal && "Skeleton CU doesn't have dwo_name.");
 
     std::string ObjectName = "";
 
     {
       std::lock_guard<std::mutex> Lock(AccessMutex);
       ObjectName = getDWOName(Unit, &NameToIndexMap, DWOIdToName);
if (SplitCU) {
       // Assuming there is unique DWOID per binary. i.e. two or more CUs don't
       // have same DWO ID.
       assert(LocListWritersByCU.count(*DWOId) == 0 &&
              "LocList writer for DWO unit already exists.");
       {
         std::lock_guard<std::mutex> Lock(AccessMutex);
         DebugLocWriter =
             LocListWritersByCU
-                .insert(
-                    {*DWOId, std::make_unique<DebugLoclistWriter>(&BC, *DWOId)})
+                .insert({*DWOId, std::make_unique<DebugLoclistWriter>(
+                                     &BC, *DWOId, 0, Unit->getVersion(), true)})
                 .first->second.get();
       }
       DebugInfoBinaryPatcher *DwoDebugInfoPatcher =
           llvm::cast<DebugInfoBinaryPatcher>(
               getBinaryDWODebugInfoPatcher(*DWOId));
       RangesBase = RangesSectionWriter->getSectionOffset();
       DWARFContext *DWOCtx = BC.getDWOContext();
       // Setting this CU offset with DWP to normalize DIE offsets to uint32_t
       if (DWOCtx && !DWOCtx->getCUIndex().getRows().empty())
         DwoDebugInfoPatcher->setDWPOffset((*SplitCU)->getOffset());
       DwoDebugInfoPatcher->setRangeBase(*RangesBase);
       DwoDebugInfoPatcher->addUnitBaseOffsetLabel((*SplitCU)->getOffset());
       DebugAbbrevWriter *DWOAbbrevWriter =
           createBinaryDWOAbbrevWriter((*SplitCU)->getContext(), *DWOId);
       updateUnitDebugInfo(*(*SplitCU), *DwoDebugInfoPatcher, *DWOAbbrevWriter,
-                          *DebugLocWriter);
+                          *DebugLocWriter, *RangesSectionWriter);
       DwoDebugInfoPatcher->clearDestinationLabels();
       if (!DwoDebugInfoPatcher->getWasRangBasedUsed())
         RangesBase = None;
     }
 
     {
       std::lock_guard<std::mutex> Lock(AccessMutex);
       DebugLocWriter = LocListWritersByCU[CUIndex].get();
     }
+    if (Unit->getVersion() == 5) {
+      RangesBase = RangesSectionWriter->getSectionOffset() +
+                   getDWARF5RngListLocListHeaderSize();
+      reinterpret_cast<DebugRangeListsSectionWriter *>(
+          RangesSectionWriter.get())
+          ->initSection(Unit->getOffset());
+    }
+
     DebugInfoPatcher->addUnitBaseOffsetLabel(Unit->getOffset());
     updateUnitDebugInfo(*Unit, *DebugInfoPatcher, *AbbrevWriter,
-                        *DebugLocWriter, RangesBase);
+                        *DebugLocWriter, *RangesSectionWriter, RangesBase);
+    if (Unit->getVersion() == 5)
+      reinterpret_cast<DebugRangeListsSectionWriter *>(
+          RangesSectionWriter.get())
+          ->finalizeSection();
   };
 
+  CUIndex = 0;
   if (opts::NoThreads || opts::DeterministicDebugInfo) {
-    for (std::unique_ptr<DWARFUnit> &CU : BC.DwCtx->compile_units())
-      processUnitDIE(0, CU.get());
+    for (std::unique_ptr<DWARFUnit> &CU : BC.DwCtx->compile_units()) {
+      processUnitDIE(CUIndex, CU.get());
+      if (CU->getVersion() == 5)
+        ++CUIndex;
+    }
   } else {
     // Update unit debug info in parallel
     ThreadPool &ThreadPool = ParallelUtilities::getThreadPool();
-    size_t CUIndex = 0;
     for (std::unique_ptr<DWARFUnit> &CU : BC.DwCtx->compile_units()) {
       ThreadPool.async(processUnitDIE, CUIndex, CU.get());
       CUIndex++;
     }
     ThreadPool.wait();
   }
 
   DebugInfoPatcher->clearDestinationLabels();
   CUOffsetMap OffsetMap = finalizeDebugSections(*DebugInfoPatcher);
 
   if (opts::WriteDWP)
     writeDWP(DWOIdToName);
   else
     writeDWOFiles(DWOIdToName);
 
   updateGdbIndexSection(OffsetMap);
 }
 
+static uint64_t getCUId(DWARFUnit &Unit) {
+  if (Unit.getVersion() == 5)
+    return Unit.getOffset();
+
+  assert(Unit.isDWOUnit() && "Unit is not Skeleton CU.");
+  return *Unit.getDWOId();
+}
+
 void DWARFRewriter::updateUnitDebugInfo(
     DWARFUnit &Unit, DebugInfoBinaryPatcher &DebugInfoPatcher,
     DebugAbbrevWriter &AbbrevWriter, DebugLocWriter &DebugLocWriter,
+    DebugRangesSectionWriter &RangesSectionWriter,
     Optional<uint64_t> RangesBase) {
   // Cache debug ranges so that the offset for identical ranges could be reused.
   std::map<DebugAddressRangesVector, uint64_t> CachedRanges;
 
   uint64_t DIEOffset = Unit.getOffset() + Unit.getHeaderSize();
   uint64_t NextCUOffset = Unit.getNextUnitOffset();
   DWARFDebugInfoEntry Die;
   DWARFDataExtractor DebugInfoData = Unit.getDebugInfoExtractor();
while (
     } else {
       // NULL entry.
       if (Depth > 0)
         --Depth;
       if (Depth == 0)
         break;
     }
 
     DWARFDie DIE(&Unit, &Die);
 
     switch (DIE.getTag()) {
     case dwarf::DW_TAG_compile_unit: {
       auto ModuleRangesOrError = DIE.getAddressRanges();
       if (!ModuleRangesOrError) {
         consumeError(ModuleRangesOrError.takeError());
         break;
       }
       DWARFAddressRangesVector &ModuleRanges = *ModuleRangesOrError;
       DebugAddressRangesVector OutputRanges =
           BC.translateModuleAddressRanges(ModuleRanges);
       const uint64_t RangesSectionOffset =
-          RangesSectionWriter->addRanges(OutputRanges);
+          RangesSectionWriter.addRanges(OutputRanges);
       if (!Unit.isDWOUnit())
         ARangesSectionWriter->addCURanges(Unit.getOffset(),
                                           std::move(OutputRanges));
       updateDWARFObjectAddressRanges(DIE, RangesSectionOffset, DebugInfoPatcher,
                                      AbbrevWriter, RangesBase);
       break;
     }
     case dwarf::DW_TAG_subprogram: {
case dwarf::DW_TAG_subprogram: {
       if (const BinaryFunction *Function =
               BC.getBinaryFunctionAtAddress(Address))
         FunctionRanges = Function->getOutputAddressRanges();
 
       if (FunctionRanges.empty())
         FunctionRanges.push_back({0, 0});
 
       updateDWARFObjectAddressRanges(
-          DIE, RangesSectionWriter->addRanges(FunctionRanges), DebugInfoPatcher,
+          DIE, RangesSectionWriter.addRanges(FunctionRanges), DebugInfoPatcher,
           AbbrevWriter);
 
       break;
     }
     case dwarf::DW_TAG_lexical_block:
     case dwarf::DW_TAG_inlined_subroutine:
     case dwarf::DW_TAG_try_block:
     case dwarf::DW_TAG_catch_block: {
-      uint64_t RangesSectionOffset =
-          RangesSectionWriter->getEmptyRangesOffset();
+      uint64_t RangesSectionOffset = RangesSectionWriter.getEmptyRangesOffset();
       Expected<DWARFAddressRangesVector> RangesOrError = DIE.getAddressRanges();
       const BinaryFunction *Function =
           RangesOrError && !RangesOrError->empty()
               ? BC.getBinaryFunctionContainingAddress(
                     RangesOrError->front().LowPC)
               : nullptr;
       if (Function) {
         DebugAddressRangesVector OutputRanges =
             Function->translateInputToOutputRanges(*RangesOrError);
         LLVM_DEBUG(if (OutputRanges.empty() != RangesOrError->empty()) {
           dbgs() << "BOLT-DEBUG: problem with DIE at 0x"
                  << Twine::utohexstr(DIE.getOffset()) << " in CU at 0x"
                  << Twine::utohexstr(Unit.getOffset()) << '\n';
         });
-        RangesSectionOffset = RangesSectionWriter->addRanges(
+        RangesSectionOffset = RangesSectionWriter.addRanges(
             std::move(OutputRanges), CachedRanges);
       } else if (!RangesOrError) {
         consumeError(RangesOrError.takeError());
       }
       updateDWARFObjectAddressRanges(DIE, RangesSectionOffset, DebugInfoPatcher,
                                      AbbrevWriter);
       break;
     }
default: {
           DebugLocationsVector InputLL;
 
           Optional<object::SectionedAddress> SectionAddress =
               Unit.getBaseAddress();
           uint64_t BaseAddress = 0;
           if (SectionAddress)
             BaseAddress = SectionAddress->Address;
 
+          if (Unit.getVersion() == 5) {
+            Optional<uint64_t> LocOffset = Unit.getLoclistOffset(Offset);
+            assert(LocOffset && "Location Offset is invalid.");
+            Offset = *LocOffset;
+          }
+
           Error E = Unit.getLocationTable().visitLocationList(
               &Offset, [&](const DWARFLocationEntry &Entry) {
                 switch (Entry.Kind) {
                 default:
                   llvm_unreachable("Unsupported DWARFLocationEntry Kind.");
                 case dwarf::DW_LLE_end_of_list:
                   return false;
-                case dwarf::DW_LLE_base_address:
+                case dwarf::DW_LLE_base_address: {
                   assert(Entry.SectionIndex == SectionedAddress::UndefSection &&
                          "absolute address expected");
                   BaseAddress = Entry.Value0;
                   break;
+                }
                 case dwarf::DW_LLE_offset_pair:
                   assert(
                       (Entry.SectionIndex == SectionedAddress::UndefSection &&
                        !Unit.isDWOUnit()) &&
                       "absolute address expected");
                   InputLL.emplace_back(DebugLocationEntry{
                       BaseAddress + Entry.Value0, BaseAddress + Entry.Value1,
                       Entry.Loc});
                   break;
-                case dwarf::DW_LLE_startx_length:
-                  assert(Unit.isDWOUnit() &&
-                         "None DWO Unit with DW_LLE_startx_length encoding.");
+                case dwarf::DW_RLE_start_length:
+                  InputLL.emplace_back(DebugLocationEntry{
+                      Entry.Value0, Entry.Value0 + Entry.Value1, Entry.Loc});
+                  break;
+                case dwarf::DW_LLE_base_addressx: {
+                  Optional<object::SectionedAddress> EntryAddress =
+                      Unit.getAddrOffsetSectionItem(Entry.Value0);
+                  assert(EntryAddress && "base Address not found.");
+                  BaseAddress = EntryAddress->Address;
+                  break;
+                }
+                case dwarf::DW_LLE_startx_length: {
                   Optional<object::SectionedAddress> EntryAddress =
                       Unit.getAddrOffsetSectionItem(Entry.Value0);
                   assert(EntryAddress && "Address does not exist.");
                   InputLL.emplace_back(DebugLocationEntry{
                       EntryAddress->Address,
                       EntryAddress->Address + Entry.Value1, Entry.Loc});
                   break;
                 }
+                case dwarf::DW_LLE_startx_endx: {
+                  Optional<object::SectionedAddress> StartAddress =
+                      Unit.getAddrOffsetSectionItem(Entry.Value0);
+                  assert(StartAddress && "Start Address does not exist.");
+                  Optional<object::SectionedAddress> EndAddress =
+                      Unit.getAddrOffsetSectionItem(Entry.Value1);
+                  assert(EndAddress && "Start Address does not exist.");
+                  InputLL.emplace_back(DebugLocationEntry{
+                      StartAddress->Address, EndAddress->Address, Entry.Loc});
+                  break;
+                }
+                }
                 return true;
               });
 
           if (E || InputLL.empty()) {
             errs() << "BOLT-WARNING: empty location list detected at 0x"
                    << Twine::utohexstr(Offset) << " for DIE at 0x"
                    << Twine::utohexstr(DIE.getOffset()) << " in CU at 0x"
                    << Twine::utohexstr(Unit.getOffset()) << '\n';
           } else {
             const uint64_t Address = InputLL.front().LowPC;
+            DebugLocationsVector OutputLL;
             if (const BinaryFunction *Function =
                     BC.getBinaryFunctionContainingAddress(Address)) {
-              DebugLocationsVector OutputLL =
-                  Function->translateInputToOutputLocationList(InputLL);
+              OutputLL = Function->translateInputToOutputLocationList(InputLL);
               LLVM_DEBUG(if (OutputLL.empty()) {
                 dbgs() << "BOLT-DEBUG: location list translated to an empty "
                           "one at 0x"
                        << Twine::utohexstr(DIE.getOffset()) << " in CU at 0x"
                        << Twine::utohexstr(Unit.getOffset()) << '\n';
               });
-              DebugLocWriter.addList(AttrOffset, std::move(OutputLL));
+            } else {
+              // It's possible for a subprogram to be removed and to have
+              // address of 0. Adding this entry to output to preserve debug
+              // information.
+              OutputLL = InputLL;
+            }
+            uint32_t LocListIndex = 0;
+            dwarf::Form Form = Value.getForm();
+            if (Form == dwarf::DW_FORM_sec_offset ||
+                Form == dwarf::DW_FORM_data4) {
+              // For DWARF5 we can access location list entry either using
+              // index, or offset. If it's offset, then it's from begnning of
+              // the file. This implementation was before we could add entries
+              // to the DIE. For DWARF4 this is no-op.
+              // TODO: For DWARF5 convert all the offset based entries to index
+              // based, and insert loclist_base if necessary.
+              LocListIndex = DebugLoclistWriter::InvalidIndex;
+            } else if (Form == dwarf::DW_FORM_loclistx) {
+              LocListIndex = Value.getRawUValue();
+            } else {
+              llvm_unreachable("Unsupported LocList access Form.");
             }
+            DebugLocWriter.addList(AttrOffset, LocListIndex,
+                                   std::move(OutputLL));
           }
         } else {
           assert((Value.isFormClass(DWARFFormValue::FC_Exprloc) ||
                   Value.isFormClass(DWARFFormValue::FC_Block)) &&
                  "unexpected DW_AT_location form");
-          if (Unit.isDWOUnit()) {
+          if (Unit.isDWOUnit() || Unit.getVersion() == 5) {
             ArrayRef<uint8_t> Expr = *Value.getAsBlock();
             DataExtractor Data(
                 StringRef((const char *)Expr.data(), Expr.size()),
                 Unit.getContext().isLittleEndian(), 0);
             DWARFExpression LocExpr(Data, Unit.getAddressByteSize(),
                                     Unit.getFormParams().Format);
+            uint32_t PrevOffset = 0;
+            constexpr uint32_t SizeOfOpcode = 1;
+            constexpr uint32_t SizeOfForm = 1;
             for (auto &Expr : LocExpr) {
-              if (Expr.getCode() != dwarf::DW_OP_GNU_addr_index)
+              if (!(Expr.getCode() == dwarf::DW_OP_GNU_addr_index ||
+                    Expr.getCode() == dwarf::DW_OP_addrx))
                 continue;
-              uint64_t Index = Expr.getRawOperand(0);
+
+              const uint64_t Index = Expr.getRawOperand(0);
               Optional<object::SectionedAddress> EntryAddress =
                   Unit.getAddrOffsetSectionItem(Index);
               assert(EntryAddress && "Address is not found.");
               assert(Index <= std::numeric_limits<uint32_t>::max() &&
                      "Invalid Operand Index.");
+              if (Expr.getCode() == dwarf::DW_OP_addrx) {
+                const uint32_t EncodingSize =
+                    Expr.getOperandEndOffset(0) - PrevOffset - SizeOfOpcode;
+                const uint32_t Index = AddrWriter->getIndexFromAddress(
+                    EntryAddress->Address, getCUId(Unit));
+                // Encoding new size.
+                SmallString<8> Tmp;
+                raw_svector_ostream OSE(Tmp);
+                encodeULEB128(Index, OSE);
+                DebugInfoPatcher.addUDataPatch(AttrOffset, Tmp.size() + 1, 1);
+                DebugInfoPatcher.addUDataPatch(AttrOffset + PrevOffset +
+                                                   SizeOfOpcode + SizeOfForm,
+                                               Index, EncodingSize);
+              } else {
+                // TODO: Re-do this as DWARF5.
                 AddrWriter->addIndexAddress(EntryAddress->Address,
                                             static_cast<uint32_t>(Index),
-                                          *Unit.getDWOId());
+                                            getCUId(Unit));
+              }
+              if (Expr.getDescription().Op[1] ==
+                  DWARFExpression::Operation::SizeNA)
+                PrevOffset = Expr.getOperandEndOffset(0);
+              else
+                PrevOffset = Expr.getOperandEndOffset(1);
             }
           }
         }
       } else if (Optional<AttrInfo> AttrVal =
                      findAttributeInfo(DIE, dwarf::DW_AT_low_pc)) {
         AttrOffset = AttrVal->Offset;
         Value = AttrVal->V;
         const Optional<uint64_t> Result = Value.getAsAddress();
default: {
                        << Twine::utohexstr(NewAddress) << '\n');
           }
 
           dwarf::Form Form = Value.getForm();
           assert(Form != dwarf::DW_FORM_LLVM_addrx_offset &&
                  "DW_FORM_LLVM_addrx_offset is not supported");
           std::lock_guard<std::mutex> Lock(DebugInfoPatcherMutex);
           if (Form == dwarf::DW_FORM_GNU_addr_index) {
-            assert(Unit.isDWOUnit() &&
-                   "DW_FORM_GNU_addr_index in Non DWO unit.");
-            uint64_t Index = Value.getRawUValue();
+            const uint64_t Index = Value.getRawUValue();
             // If there is no new address, storing old address.
             // Re-using Index to make implementation easier.
-            // DW_FORM_GNU_addr_index is variable lenght encoding so we either
-            // have to create indices of same sizes, or use same index.
+            // DW_FORM_GNU_addr_index is variable lenght encoding
+            // so we either have to create indices of same sizes, or use same
+            // index.
+            // TODO: We can now re-write .debug_info. This can be simplified to
+            // just getting a new index and creating a patch.
             AddrWriter->addIndexAddress(NewAddress ? NewAddress : Address,
-                                        Index, *Unit.getDWOId());
+                                        Index, getCUId(Unit));
+          } else if (Form == dwarf::DW_FORM_addrx) {
+            const uint32_t Index = AddrWriter->getIndexFromAddress(
+                NewAddress ? NewAddress : Address, getCUId(Unit));
+            DebugInfoPatcher.addUDataPatch(AttrOffset, Index, AttrVal->Size);
           } else {
             DebugInfoPatcher.addLE64Patch(AttrOffset, NewAddress);
           }
         } else if (opts::Verbosity >= 1) {
           errs() << "BOLT-WARNING: unexpected form value for attribute at 0x"
                  << Twine::utohexstr(AttrOffset);
         }
       }
if (!AbbreviationDecl) {
     return;
   }
 
   if (RangesBase) {
     // If DW_AT_GNU_ranges_base is present, update it. No further modifications
     // are needed for ranges base.
     Optional<AttrInfo> RangesBaseAttrInfo =
         findAttributeInfo(DIE, dwarf::DW_AT_GNU_ranges_base);
+    if (!RangesBaseAttrInfo)
+      RangesBaseAttrInfo = findAttributeInfo(DIE, dwarf::DW_AT_rnglists_base);
+
     if (RangesBaseAttrInfo) {
       DebugInfoPatcher.addLE32Patch(RangesBaseAttrInfo->Offset,
                                     static_cast<uint32_t>(*RangesBase),
                                     RangesBaseAttrInfo->Size);
       RangesBase = None;
     }
   }
 
   Optional<AttrInfo> LowPCAttrInfo =
       findAttributeInfo(DIE, dwarf::DW_AT_low_pc);
-  if (AbbreviationDecl->findAttributeIndex(dwarf::DW_AT_ranges)) {
+  if (Optional<AttrInfo> AttrVal =
+          findAttributeInfo(DIE, dwarf::DW_AT_ranges)) {
     // Case 1: The object was already non-contiguous and had DW_AT_ranges.
     // In this case we simply need to update the value of DW_AT_ranges
     // and introduce DW_AT_GNU_ranges_base if required.
-    Optional<AttrInfo> AttrVal = findAttributeInfo(DIE, dwarf::DW_AT_ranges);
     std::lock_guard<std::mutex> Lock(DebugInfoPatcherMutex);
+    // For DWARF5 converting all of DW_AT_ranges into DW_FORM_rnglistx
+    bool Converted = false;
+    if (DIE.getDwarfUnit()->getVersion() == 5 &&
+        AttrVal->V.getForm() == dwarf::DW_FORM_sec_offset) {
+      AbbrevWriter.addAttributePatch(*DIE.getDwarfUnit(), AbbreviationDecl,
+                                     dwarf::DW_AT_ranges, dwarf::DW_AT_ranges,
+                                     dwarf::DW_FORM_rnglistx);
+      Converted = true;
+    }
+    if (Converted || AttrVal->V.getForm() == dwarf::DW_FORM_rnglistx)
+      DebugInfoPatcher.addUDataPatch(AttrVal->Offset, DebugRangesOffset,
+                                     AttrVal->Size);
+    else
       DebugInfoPatcher.addLE32Patch(
           AttrVal->Offset, DebugRangesOffset - DebugInfoPatcher.getRangeBase(),
           AttrVal->Size);
 
     if (!RangesBase) {
       if (LowPCAttrInfo &&
           LowPCAttrInfo->V.getForm() != dwarf::DW_FORM_GNU_addr_index &&
           LowPCAttrInfo->V.getForm() != dwarf::DW_FORM_addrx)
         DebugInfoPatcher.addLE64Patch(LowPCAttrInfo->Offset, 0);
       return;
     }
std::unique_ptr<DebugStrBufferVector> DebugStrSectionContents =
         StrWriter->finalize();
     BC.registerOrUpdateNoteSection(".debug_str",
                                    copyByteArray(*DebugStrSectionContents),
                                    DebugStrSectionContents->size());
   }
 
   std::unique_ptr<DebugBufferVector> RangesSectionContents =
       RangesSectionWriter->finalize();
-  BC.registerOrUpdateNoteSection(".debug_ranges",
-                                 copyByteArray(*RangesSectionContents),
-                                 RangesSectionContents->size());
+  BC.registerOrUpdateNoteSection(
+      llvm::isa<DebugRangeListsSectionWriter>(*RangesSectionWriter)
+          ? ".debug_rnglists"
+          : ".debug_ranges",
+      copyByteArray(*RangesSectionContents), RangesSectionContents->size());
+
+  if (BC.isDWARF5Used()) {
+    std::unique_ptr<DebugBufferVector> LocationListSectionContents =
+        makeFinalLocListsSection(DebugInfoPatcher, DWARFVersion::DWARF5);
+    BC.registerOrUpdateNoteSection(".debug_loclists",
+                                   copyByteArray(*LocationListSectionContents),
+                                   LocationListSectionContents->size());
+  }
 
+  if (BC.isDWARFLegacyUsed()) {
     std::unique_ptr<DebugBufferVector> LocationListSectionContents =
-      makeFinalLocListsSection(DebugInfoPatcher);
+        makeFinalLocListsSection(DebugInfoPatcher, DWARFVersion::DWARFLegacy);
     BC.registerOrUpdateNoteSection(".debug_loc",
                                    copyByteArray(*LocationListSectionContents),
                                    LocationListSectionContents->size());
+  }
 
   // AddrWriter should be finalized after debug_loc since more addresses can be
   // added there.
   if (AddrWriter->isInitialized()) {
     AddressSectionBuffer AddressSectionContents = AddrWriter->finalize();
     BC.registerOrUpdateNoteSection(".debug_addr",
                                    copyByteArray(AddressSectionContents),
                                    AddressSectionContents.size());
     for (auto &CU : BC.DwCtx->compile_units()) {
       DWARFDie DIE = CU->getUnitDIE();
-      if (Optional<AttrInfo> AttrVal =
-              findAttributeInfo(DIE, dwarf::DW_AT_GNU_addr_base)) {
-        uint64_t Offset = AddrWriter->getOffset(*CU->getDWOId());
-        DebugInfoPatcher.addLE32Patch(
-            AttrVal->Offset, static_cast<int32_t>(Offset), AttrVal->Size);
+      uint64_t Offset = 0;
+      uint64_t AttrOffset = 0;
+      uint32_t Size = 0;
+      Optional<AttrInfo> AttrValGnu =
+          findAttributeInfo(DIE, dwarf::DW_AT_GNU_addr_base);
+      Optional<AttrInfo> AttrVal =
+          findAttributeInfo(DIE, dwarf::DW_AT_addr_base);
+      Offset = AddrWriter->getOffset(*CU);
+
+      if (AttrValGnu) {
+        AttrOffset = AttrValGnu->Offset;
+        Size = AttrValGnu->Size;
+      }
+
+      if (AttrVal) {
+        AttrOffset = AttrVal->Offset;
+        Size = AttrVal->Size;
       }
+
+      if (AttrValGnu || AttrVal) {
+        DebugInfoPatcher.addLE32Patch(AttrOffset, static_cast<int32_t>(Offset),
+                                      Size);
+      } else if (CU->getVersion() == 5) {
+        // A case where we were not using .debug_addr section, but after update
+        // now using it.
+        const DWARFAbbreviationDeclaration *Abbrev =
+            DIE.getAbbreviationDeclarationPtr();
+        AbbrevWriter->addAttribute(*CU, Abbrev, dwarf::DW_AT_addr_base,
+                                   dwarf::DW_FORM_sec_offset);
+        DebugInfoPatcher.insertNewEntry(DIE, static_cast<int32_t>(Offset));
+      } else
+        llvm_unreachable(
+            "DWO CU uses .debug_address, but DW_AT_GNU_addr_base is missing.");
     }
   }
 
   std::unique_ptr<DebugBufferVector> AbbrevSectionContents =
       AbbrevWriter->finalize();
   BC.registerOrUpdateNoteSection(".debug_abbrev",
                                  copyByteArray(*AbbrevSectionContents),
                                  AbbrevSectionContents->size());
 
   // Update abbreviation offsets for CUs/TUs if they were changed.
   SimpleBinaryPatcher *DebugTypesPatcher = nullptr;
   for (auto &Unit : BC.DwCtx->normal_units()) {
     const uint64_t NewAbbrevOffset =
         AbbrevWriter->getAbbreviationsOffsetForUnit(*Unit);
     if (Unit->getAbbreviationsOffset() == NewAbbrevOffset)
       continue;
 
-    // DWARFv4
+    // DWARFv4 or earlier
     // unit_length - 4 bytes
     // version - 2 bytes
     // So + 6 to patch debug_abbrev_offset
-    constexpr uint64_t AbbrevFieldOffset = 6;
-    if (!Unit->isTypeUnit()) {
-      DebugInfoPatcher.addLE32Patch(Unit->getOffset() + AbbrevFieldOffset,
+    constexpr uint64_t AbbrevFieldOffsetLegacy = 6;
+    // DWARFv5
+    // unit_length - 4 bytes
+    // version - 2 bytes
+    // unit_type - 1 byte
+    // address_size - 1 byte
+    // So + 8 to patch debug_abbrev_offset
+    constexpr uint64_t AbbrevFieldOffsetV5 = 8;
+    uint64_t AbbrevOffset =
+        Unit->getVersion() == 5 ? AbbrevFieldOffsetV5 : AbbrevFieldOffsetLegacy;
+    if (!Unit->isTypeUnit() || Unit->getVersion() == 5) {
+      DebugInfoPatcher.addLE32Patch(Unit->getOffset() + AbbrevOffset,
                                     static_cast<uint32_t>(NewAbbrevOffset));
       continue;
     }
 
     if (!DebugTypesPatcher) {
       ErrorOr<BinarySection &> DebugTypes =
           BC.getUniqueSectionByName(".debug_types");
       DebugTypes->registerPatcher(std::make_unique<SimpleBinaryPatcher>());
       DebugTypesPatcher =
           static_cast<SimpleBinaryPatcher *>(DebugTypes->getPatcher());
     }
-    DebugTypesPatcher->addLE32Patch(Unit->getOffset() + AbbrevFieldOffset,
+    DebugTypesPatcher->addLE32Patch(Unit->getOffset() + AbbrevOffset,
                                     static_cast<uint32_t>(NewAbbrevOffset));
   }
 
   // No more creating new DebugInfoPatches.
   CUOffsetMap CUMap =
       DebugInfoPatcher.computeNewOffsets(*BC.DwCtx.get(), false);
 
   // Skip .debug_aranges if we are re-generating .gdb_index.
void DWARFRewriter::updateGdbIndexSection(CUOffsetMap &CUMap) {
   memcpy(Buffer, Data, TrailingSize);
 
   // Register the new section.
   BC.registerOrUpdateNoteSection(".gdb_index", NewGdbIndexContents,
                                  NewGdbIndexSize);
 }
 
 std::unique_ptr<DebugBufferVector>
-DWARFRewriter::makeFinalLocListsSection(SimpleBinaryPatcher &DebugInfoPatcher) {
+DWARFRewriter::makeFinalLocListsSection(SimpleBinaryPatcher &DebugInfoPatcher,
+                                        DWARFVersion Version) {
   auto LocBuffer = std::make_unique<DebugBufferVector>();
   auto LocStream = std::make_unique<raw_svector_ostream>(*LocBuffer);
   auto Writer =
       std::unique_ptr<MCObjectWriter>(BC.createObjectWriter(*LocStream));
 
   uint64_t SectionOffset = 0;
-
   // Add an empty list as the first entry;
+  if (LocListWritersByCU.empty() ||
+      LocListWritersByCU.begin()->second.get()->getDwarfVersion() < 5) {
+    // Should be fine for both DWARF4 and DWARF5?
     const char Zeroes[16] = {0};
     *LocStream << StringRef(Zeroes, 16);
     SectionOffset += 2 * 8;
+  }
 
   for (std::pair<const uint64_t, std::unique_ptr<DebugLocWriter>> &Loc :
        LocListWritersByCU) {
     DebugLocWriter *LocWriter = Loc.second.get();
-    if (auto *LocListWriter = llvm::dyn_cast<DebugLoclistWriter>(LocWriter)) {
+    auto *LocListWriter = llvm::dyn_cast<DebugLoclistWriter>(LocWriter);
+
+    if (Version == DWARFVersion::DWARF5 &&
+        (!LocListWriter || LocListWriter->getDwarfVersion() == 4))
+      continue;
+
+    if (Version == DWARFVersion::DWARFLegacy &&
+        (LocListWriter && LocListWriter->getDwarfVersion() == 5))
+      continue;
+    if (LocListWriter && (LocListWriter->getDwarfVersion() == 4 ||
+                          (LocListWriter->getDwarfVersion() == 5 &&
+                           LocListWriter->isSplitDwarf()))) {
       SimpleBinaryPatcher *Patcher =
-          getBinaryDWODebugInfoPatcher(LocListWriter->getDWOID());
+          getBinaryDWODebugInfoPatcher(LocListWriter->getCUID());
       LocListWriter->finalize(0, *Patcher);
       continue;
     }
     LocWriter->finalize(SectionOffset, DebugInfoPatcher);
     std::unique_ptr<DebugBufferVector> CurrCULocationLists =
         LocWriter->getBuffer();
     *LocStream << *CurrCULocationLists;
     SectionOffset += CurrCULocationLists->size();
void getRangeAttrData(DWARFDie DIE, Optional<AttrInfo> &LowPCVal,
   LowPCVal = findAttributeInfo(DIE, dwarf::DW_AT_low_pc);
   HighPCVal = findAttributeInfo(DIE, dwarf::DW_AT_high_pc);
   uint64_t LowPCOffset = LowPCVal->Offset;
   uint64_t HighPCOffset = HighPCVal->Offset;
   dwarf::Form LowPCForm = LowPCVal->V.getForm();
   dwarf::Form HighPCForm = HighPCVal->V.getForm();
 
   if (LowPCForm != dwarf::DW_FORM_addr &&
-      LowPCForm != dwarf::DW_FORM_GNU_addr_index) {
+      LowPCForm != dwarf::DW_FORM_GNU_addr_index &&
+      LowPCForm != dwarf::DW_FORM_addrx) {
     errs() << "BOLT-WARNING: unexpected low_pc form value. Cannot update DIE "
            << "at offset 0x" << Twine::utohexstr(DIE.getOffset()) << "\n";
     return;
   }
   if (HighPCForm != dwarf::DW_FORM_addr && HighPCForm != dwarf::DW_FORM_data8 &&
       HighPCForm != dwarf::DW_FORM_data4 &&
       HighPCForm != dwarf::DW_FORM_data2 &&
       HighPCForm != dwarf::DW_FORM_data1 &&
       HighPCForm != dwarf::DW_FORM_udata) {
     errs() << "BOLT-WARNING: unexpected high_pc form value. Cannot update DIE "
            << "at offset 0x" << Twine::utohexstr(DIE.getOffset()) << "\n";
     return;
   }
   if ((LowPCOffset == -1U || (LowPCOffset + 8 != HighPCOffset)) &&
-      LowPCForm != dwarf::DW_FORM_GNU_addr_index) {
+      LowPCForm != dwarf::DW_FORM_GNU_addr_index &&
+      LowPCForm != dwarf::DW_FORM_addrx) {
     errs() << "BOLT-WARNING: high_pc expected immediately after low_pc. "
            << "Cannot update DIE at offset 0x"
            << Twine::utohexstr(DIE.getOffset()) << '\n';
     return;
   }
 }
 
 } // namespace
 
 void DWARFRewriter::convertToRangesPatchAbbrev(
     const DWARFUnit &Unit, const DWARFAbbreviationDeclaration *Abbrev,
     DebugAbbrevWriter &AbbrevWriter, Optional<uint64_t> RangesBase) {
-  auto getAttributeForm = [&Abbrev](const dwarf::Attribute Attr) {
-    Optional<uint32_t> Index = Abbrev->findAttributeIndex(Attr);
-    assert(Index && "attribute not found");
-    return Abbrev->getFormByIndex(*Index);
-  };
-  dwarf::Form LowPCForm = getAttributeForm(dwarf::DW_AT_low_pc);
 
-  // DW_FORM_GNU_addr_index is already variable encoding so nothing to do
-  // there.
-  if (RangesBase) {
-    assert(LowPCForm != dwarf::DW_FORM_GNU_addr_index);
-    AbbrevWriter.addAttribute(Unit, Abbrev, dwarf::DW_AT_GNU_ranges_base,
+  dwarf::Attribute RangeBaseAttribute = dwarf::DW_AT_GNU_ranges_base;
+  dwarf::Form RangesForm = dwarf::DW_FORM_sec_offset;
+
+  if (Unit.getVersion() == 5) {
+    RangeBaseAttribute = dwarf::DW_AT_rnglists_base;
+    RangesForm = dwarf::DW_FORM_rnglistx;
+  }
+  // If we hit this point it means we converted subprogram DIEs from
+  // low_pc/high_pc into ranges. The CU originally didn't have DW_AT_*_base, so
+  // we are adding it here.
+  if (RangesBase)
+    AbbrevWriter.addAttribute(Unit, Abbrev, RangeBaseAttribute,
                               dwarf::DW_FORM_sec_offset);
-  }
 
+  // Converting DW_AT_high_pc into DW_AT_ranges.
+  // For DWARF4 it's DW_FORM_sec_offset.
+  // For DWARF5 it can be either DW_FORM_sec_offset or DW_FORM_rnglistx.
+  // For consistency for DWARF5 we always use DW_FORM_rnglistx.
   AbbrevWriter.addAttributePatch(Unit, Abbrev, dwarf::DW_AT_high_pc,
-                                 dwarf::DW_AT_ranges,
-                                 dwarf::DW_FORM_sec_offset);
+                                 dwarf::DW_AT_ranges, RangesForm);
 }
 
 void DWARFRewriter::convertToRangesPatchDebugInfo(
     DWARFDie DIE, uint64_t RangesSectionOffset,
     SimpleBinaryPatcher &DebugInfoPatcher, Optional<uint64_t> RangesBase) {
   Optional<AttrInfo> LowPCVal = None;
   Optional<AttrInfo> HighPCVal = None;
   getRangeAttrData(DIE, LowPCVal, HighPCVal);
   uint64_t LowPCOffset = LowPCVal->Offset;
   uint64_t HighPCOffset = HighPCVal->Offset;
 
   std::lock_guard<std::mutex> Lock(DebugInfoPatcherMutex);
   uint32_t BaseOffset = 0;
-  if (LowPCVal->V.getForm() == dwarf::DW_FORM_GNU_addr_index) {
+  dwarf::Form LowForm = LowPCVal->V.getForm();
+
+  // In DWARF4 for DW_AT_low_pc in binary DW_FORM_addr is used. In the DWO
+  // section DW_FORM_GNU_addr_index is used. So for if we are converting
+  // DW_AT_low_pc/DW_AT_high_pc and see DW_FORM_GNU_addr_index. We are
+  // converting in DWO section, and DW_AT_ranges [DW_FORM_sec_offset] is
+  // relative to DW_AT_GNU_ranges_base.
+  if (LowForm == dwarf::DW_FORM_GNU_addr_index) {
     // Use ULEB128 for the value.
-    DebugInfoPatcher.addUDataPatch(LowPCOffset, 0,
-                                   std::abs(int(HighPCOffset - LowPCOffset)));
+    DebugInfoPatcher.addUDataPatch(LowPCOffset, 0, LowPCVal->Size);
     // Ranges are relative to DW_AT_GNU_ranges_base.
     BaseOffset = DebugInfoPatcher.getRangeBase();
   } else {
+    // In DWARF 5 we can have DW_AT_low_pc either as DW_FORM_addr, or
+    // DW_FORM_addrx. Former is when DW_AT_rnglists_base is present. Latter is
+    // when it's absent.
+    if (LowForm == dwarf::DW_FORM_addrx) {
+      uint32_t Index =
+          AddrWriter->getIndexFromAddress(0, DIE.getDwarfUnit()->getOffset());
+      DebugInfoPatcher.addUDataPatch(LowPCOffset, Index, LowPCVal->Size);
+    } else
       DebugInfoPatcher.addLE64Patch(LowPCOffset, 0);
-    // If DW_AT_GNU_ranges_base was inserted.
+
+    // Original CU didn't have DW_AT_*_base. We converted it's children (or
+    // dwo), so need to insert it into CU.
     if (RangesBase)
       reinterpret_cast<DebugInfoBinaryPatcher &>(DebugInfoPatcher)
           .insertNewEntry(DIE, *RangesBase);
   }
-  DebugInfoPatcher.addLE32Patch(HighPCOffset, RangesSectionOffset - BaseOffset,
+
+  // HighPC was conveted into DW_AT_ranges.
+  // For DWARF5 we only access ranges throught index.
+  if (DIE.getDwarfUnit()->getVersion() == 5)
+    DebugInfoPatcher.addUDataPatch(HighPCOffset, RangesSectionOffset,
                                    HighPCVal->Size);
+  else
+    DebugInfoPatcher.addLE32Patch(
+        HighPCOffset, RangesSectionOffset - BaseOffset, HighPCVal->Size);
 }

bolt/lib/Rewrite/RewriteInstance.cpp

WriteBoltInfoSection("bolt-info",
   cl::ZeroOrMore,
   cl::Hidden,
   cl::cat(BoltOutputCategory));
 
 } // namespace opts
 
 constexpr const char *RewriteInstance::SectionsToOverwrite[];
 std::vector<std::string> RewriteInstance::DebugSectionsToOverwrite = {
-    ".debug_abbrev", ".debug_aranges", ".debug_line", ".debug_loc",
-    ".debug_ranges", ".gdb_index",     ".debug_addr"};
+    ".debug_abbrev", ".debug_aranges",  ".debug_line",   ".debug_line_str",
+    ".debug_loc",    ".debug_loclists", ".debug_ranges", ".debug_rnglists",
+    ".gdb_index",    ".debug_addr"};
 
 const char RewriteInstance::TimerGroupName[] = "rewrite";
 const char RewriteInstance::TimerGroupDesc[] = "Rewrite passes";
 
 namespace llvm {
 namespace bolt {
 
 extern const char *BoltRevision;

bolt/test/X86/Inputs/dwarf5_helper.s

+# clang++ helper.cpp -g -O2 -S
+# int fooVar = 0;
+# void useFoo(int * x) {
+# *x += 4;
+# }
+#
+# int  foo(int argc) {
+#    int x = argc;
+#    useFoo(&x);
+#    return x;
+# }
+  .text
+  .file "foo.cpp"
+  .file 0 "/testLocListMultiple" "foo.cpp" md5 0x9410f31145d031fcc1f2464b809e409a
+  .globl  _Z6useFooPi                     # -- Begin function _Z6useFooPi
+  .p2align  4, 0x90
+  .type _Z6useFooPi,@function
+_Z6useFooPi:                            # @_Z6useFooPi
+.Lfunc_begin0:
+  .loc  0 2 0                           # foo.cpp:2:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  #DEBUG_VALUE: useFoo:x <- $rdi
+  .loc  0 3 4 prologue_end              # foo.cpp:3:4
+  addl  $4, (%rdi)
+  .loc  0 4 1                           # foo.cpp:4:1
+  retq
+.Ltmp0:
+.Lfunc_end0:
+  .size _Z6useFooPi, .Lfunc_end0-_Z6useFooPi
+  .cfi_endproc
+                                        # -- End function
+  .globl  _Z3fooi                         # -- Begin function _Z3fooi
+  .p2align  4, 0x90
+  .type _Z3fooi,@function
+_Z3fooi:                                # @_Z3fooi
+.Lfunc_begin1:
+  .loc  0 6 0                           # foo.cpp:6:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  #DEBUG_VALUE: foo:argc <- $edi
+  #DEBUG_VALUE: foo:x <- $edi
+                                        # kill: def $edi killed $edi def $rdi
+  #DEBUG_VALUE: useFoo:x <- undef
+  .loc  0 3 4 prologue_end              # foo.cpp:3:4
+  leal  4(%rdi), %eax
+.Ltmp1:
+  #DEBUG_VALUE: foo:x <- $eax
+  .loc  0 9 4                           # foo.cpp:9:4
+  retq
+.Ltmp2:
+.Lfunc_end1:
+  .size _Z3fooi, .Lfunc_end1-_Z3fooi
+  .cfi_endproc
+                                        # -- End function
+  .type fooVar,@object                  # @fooVar
+  .bss
+  .globl  fooVar
+  .p2align  2
+fooVar:
+  .long 0                               # 0x0
+  .size fooVar, 4
+
+  .section  .debug_loclists,"",@progbits
+  .long .Ldebug_list_header_end0-.Ldebug_list_header_start0 # Length
+.Ldebug_list_header_start0:
+  .short  5                               # Version
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+  .long 1                               # Offset entry count
+.Lloclists_table_base0:
+  .long .Ldebug_loc0-.Lloclists_table_base0
+.Ldebug_loc0:
+  .byte 4                               # DW_LLE_offset_pair
+  .uleb128 .Lfunc_begin1-.Lfunc_begin0    #   starting offset
+  .uleb128 .Ltmp1-.Lfunc_begin0           #   ending offset
+  .byte 1                               # Loc expr size
+  .byte 85                              # super-register DW_OP_reg5
+  .byte 4                               # DW_LLE_offset_pair
+  .uleb128 .Ltmp1-.Lfunc_begin0           #   starting offset
+  .uleb128 .Lfunc_end1-.Lfunc_begin0      #   ending offset
+  .byte 1                               # Loc expr size
+  .byte 80                              # super-register DW_OP_reg0
+  .byte 0                               # DW_LLE_end_of_list
+.Ldebug_list_header_end0:
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .ascii  "\214\001"                      # DW_AT_loclists_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 52                              # DW_TAG_variable
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 4                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 5                               # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 6                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 110                             # DW_AT_linkage_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 32                              # DW_AT_inline
+  .byte 33                              # DW_FORM_implicit_const
+  .byte 1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 7                               # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 8                               # Abbreviation Code
+  .byte 15                              # DW_TAG_pointer_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 9                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 110                             # DW_AT_linkage_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 10                              # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 11                              # Abbreviation Code
+  .byte 52                              # DW_TAG_variable
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 34                              # DW_FORM_loclistx
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 12                              # Abbreviation Code
+  .byte 29                              # DW_TAG_inlined_subroutine
+  .byte 0                               # DW_CHILDREN_no
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 88                              # DW_AT_call_file
+  .byte 11                              # DW_FORM_data1
+  .byte 89                              # DW_AT_call_line
+  .byte 11                              # DW_FORM_data1
+  .byte 87                              # DW_AT_call_column
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 1                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .byte 1                               # Abbrev [1] 0xc:0x83 DW_TAG_compile_unit
+  .byte 0                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 1                               # DW_AT_name
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .byte 2                               # DW_AT_comp_dir
+  .byte 1                               # DW_AT_low_pc
+  .long .Lfunc_end1-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+  .long .Lloclists_table_base0          # DW_AT_loclists_base
+  .byte 2                               # Abbrev [2] 0x27:0xb DW_TAG_variable
+  .byte 3                               # DW_AT_name
+  .long 50                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .byte 2                               # DW_AT_location
+  .byte 161
+  .byte 0
+  .byte 3                               # Abbrev [3] 0x32:0x4 DW_TAG_base_type
+  .byte 4                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 4                               # Abbrev [4] 0x36:0x14 DW_TAG_subprogram
+  .byte 1                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .long 74                              # DW_AT_abstract_origin
+  .byte 5                               # Abbrev [5] 0x42:0x7 DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 85
+  .long 79                              # DW_AT_abstract_origin
+  .byte 0                               # End Of Children Mark
+  .byte 6                               # Abbrev [6] 0x4a:0xe DW_TAG_subprogram
+  .byte 5                               # DW_AT_linkage_name
+  .byte 6                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 2                               # DW_AT_decl_line
+                                        # DW_AT_external
+                                        # DW_AT_inline
+  .byte 7                               # Abbrev [7] 0x4f:0x8 DW_TAG_formal_parameter
+  .byte 7                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 2                               # DW_AT_decl_line
+  .long 88                              # DW_AT_type
+  .byte 0                               # End Of Children Mark
+  .byte 8                               # Abbrev [8] 0x58:0x5 DW_TAG_pointer_type
+  .long 50                              # DW_AT_type
+  .byte 9                               # Abbrev [9] 0x5d:0x31 DW_TAG_subprogram
+  .byte 2                               # DW_AT_low_pc
+  .long .Lfunc_end1-.Lfunc_begin1       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .byte 8                               # DW_AT_linkage_name
+  .byte 9                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 6                               # DW_AT_decl_line
+  .long 50                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 10                              # Abbrev [10] 0x6d:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 85
+  .byte 10                              # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 6                               # DW_AT_decl_line
+  .long 50                              # DW_AT_type
+  .byte 11                              # Abbrev [11] 0x77:0x9 DW_TAG_variable
+  .byte 0                               # DW_AT_location
+  .byte 7                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 7                               # DW_AT_decl_line
+  .long 50                              # DW_AT_type
+  .byte 12                              # Abbrev [12] 0x80:0xd DW_TAG_inlined_subroutine
+  .long 74                              # DW_AT_abstract_origin
+  .byte 2                               # DW_AT_low_pc
+  .long .Ltmp1-.Lfunc_begin1            # DW_AT_high_pc
+  .byte 0                               # DW_AT_call_file
+  .byte 8                               # DW_AT_call_line
+  .byte 4                               # DW_AT_call_column
+  .byte 0                               # End Of Children Mark
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 48                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Linfo_string0:
+  .asciz  "clang version 15.0.0)" # string offset=0
+.Linfo_string1:
+  .asciz  "foo.cpp"                       # string offset=134
+.Linfo_string2:
+  .asciz  "/testLocListMultiple" # string offset=142
+.Linfo_string3:
+  .asciz  "fooVar"                        # string offset=199
+.Linfo_string4:
+  .asciz  "int"                           # string offset=206
+.Linfo_string5:
+  .asciz  "_Z6useFooPi"                   # string offset=210
+.Linfo_string6:
+  .asciz  "useFoo"                        # string offset=222
+.Linfo_string7:
+  .asciz  "x"                             # string offset=229
+.Linfo_string8:
+  .asciz  "_Z3fooi"                       # string offset=231
+.Linfo_string9:
+  .asciz  "foo"                           # string offset=239
+.Linfo_string10:
+  .asciz  "argc"                          # string offset=243
+  .section  .debug_str_offsets,"",@progbits
+  .long .Linfo_string0
+  .long .Linfo_string1
+  .long .Linfo_string2
+  .long .Linfo_string3
+  .long .Linfo_string4
+  .long .Linfo_string5
+  .long .Linfo_string6
+  .long .Linfo_string7
+  .long .Linfo_string8
+  .long .Linfo_string9
+  .long .Linfo_string10
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad fooVar
+  .quad .Lfunc_begin0
+  .quad .Lfunc_begin1
+.Ldebug_addr_end0:
+  .ident  "clang version 15.0.0"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/Inputs/dwarf5_main.s

+# clang++ main.cpp -g -O2 -S
+# void use(int * x, int * y) {
+# *x += 4;
+# *y -= 2;
+# }
+#
+# extern int fooVar;
+# int  main(int argc, char *argv[]) {
+#    int x = argc;
+#    int y = fooVar + 3;
+#    use(&x, &y);
+#    return x + y;
+# }
+
+
+  .text
+  .file "main.cpp"
+  .globl  _Z3usePiS_                      # -- Begin function _Z3usePiS_
+  .p2align  4, 0x90
+  .type _Z3usePiS_,@function
+_Z3usePiS_:                             # @_Z3usePiS_
+.Lfunc_begin0:
+  .file 0 "/testLocListMultiple" "main.cpp" md5 0xb1a1551182284263b0faa0cae08277da
+  .loc  0 1 0                           # main.cpp:1:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  #DEBUG_VALUE: use:x <- $rdi
+  #DEBUG_VALUE: use:y <- $rsi
+  .loc  0 2 4 prologue_end              # main.cpp:2:4
+  addl  $4, (%rdi)
+  .loc  0 3 4                           # main.cpp:3:4
+  addl  $-2, (%rsi)
+  .loc  0 4 1                           # main.cpp:4:1
+  retq
+.Ltmp0:
+.Lfunc_end0:
+  .size _Z3usePiS_, .Lfunc_end0-_Z3usePiS_
+  .cfi_endproc
+                                        # -- End function
+  .globl  main                            # -- Begin function main
+  .p2align  4, 0x90
+  .type main,@function
+main:                                   # @main
+.Lfunc_begin1:
+  .loc  0 7 0                           # main.cpp:7:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  #DEBUG_VALUE: main:argc <- $edi
+  #DEBUG_VALUE: main:argv <- $rsi
+  #DEBUG_VALUE: main:x <- $edi
+                                        # kill: def $edi killed $edi def $rdi
+  .loc  0 9 12 prologue_end             # main.cpp:9:12
+  movl  fooVar(%rip), %eax
+.Ltmp1:
+  #DEBUG_VALUE: main:y <- [DW_OP_plus_uconst 3, DW_OP_stack_value] $eax
+  #DEBUG_VALUE: main:y <- [DW_OP_plus_uconst 1, DW_OP_stack_value] $eax
+  #DEBUG_VALUE: main:x <- [DW_OP_plus_uconst 4, DW_OP_stack_value] $edi
+  .loc  0 11 13                         # main.cpp:11:13
+  addl  %edi, %eax
+.Ltmp2:
+  addl  $5, %eax
+  .loc  0 11 4 is_stmt 0                # main.cpp:11:4
+  retq
+.Ltmp3:
+.Lfunc_end1:
+  .size main, .Lfunc_end1-main
+  .cfi_endproc
+                                        # -- End function
+  .section  .debug_loclists,"",@progbits
+  .long .Ldebug_list_header_end0-.Ldebug_list_header_start0 # Length
+.Ldebug_list_header_start0:
+  .short  5                               # Version
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+  .long 2                               # Offset entry count
+.Lloclists_table_base0:
+  .long .Ldebug_loc0-.Lloclists_table_base0
+  .long .Ldebug_loc1-.Lloclists_table_base0
+.Ldebug_loc0:
+  .byte 4                               # DW_LLE_offset_pair
+  .uleb128 .Lfunc_begin1-.Lfunc_begin0    #   starting offset
+  .uleb128 .Ltmp1-.Lfunc_begin0           #   ending offset
+  .byte 1                               # Loc expr size
+  .byte 85                              # super-register DW_OP_reg5
+  .byte 4                               # DW_LLE_offset_pair
+  .uleb128 .Ltmp1-.Lfunc_begin0           #   starting offset
+  .uleb128 .Lfunc_end1-.Lfunc_begin0      #   ending offset
+  .byte 10                              # Loc expr size
+  .byte 117                             # DW_OP_breg5
+  .byte 4                               # 4
+  .byte 16                              # DW_OP_constu
+  .byte 255                             # 4294967295
+  .byte 255                             #
+  .byte 255                             #
+  .byte 255                             #
+  .byte 15                              #
+  .byte 26                              # DW_OP_and
+  .byte 159                             # DW_OP_stack_value
+  .byte 0                               # DW_LLE_end_of_list
+.Ldebug_loc1:
+  .byte 4                               # DW_LLE_offset_pair
+  .uleb128 .Ltmp1-.Lfunc_begin0           #   starting offset
+  .uleb128 .Ltmp2-.Lfunc_begin0           #   ending offset
+  .byte 10                              # Loc expr size
+  .byte 112                             # DW_OP_breg0
+  .byte 1                               # 1
+  .byte 16                              # DW_OP_constu
+  .byte 255                             # 4294967295
+  .byte 255                             #
+  .byte 255                             #
+  .byte 255                             #
+  .byte 15                              #
+  .byte 26                              # DW_OP_and
+  .byte 159                             # DW_OP_stack_value
+  .byte 0                               # DW_LLE_end_of_list
+.Ldebug_list_header_end0:
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .ascii  "\214\001"                      # DW_AT_loclists_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 110                             # DW_AT_linkage_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 4                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 5                               # Abbreviation Code
+  .byte 52                              # DW_TAG_variable
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 34                              # DW_FORM_loclistx
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 6                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 7                               # Abbreviation Code
+  .byte 15                              # DW_TAG_pointer_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 1                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .byte 1                               # Abbrev [1] 0xc:0x8a DW_TAG_compile_unit
+  .byte 0                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 1                               # DW_AT_name
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .byte 2                               # DW_AT_comp_dir
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end1-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+  .long .Lloclists_table_base0          # DW_AT_loclists_base
+  .byte 2                               # Abbrev [2] 0x27:0x21 DW_TAG_subprogram
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .byte 3                               # DW_AT_linkage_name
+  .byte 4                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+                                        # DW_AT_external
+  .byte 3                               # Abbrev [3] 0x33:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 85
+  .byte 7                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 130                             # DW_AT_type
+  .byte 3                               # Abbrev [3] 0x3d:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 84
+  .byte 8                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 130                             # DW_AT_type
+  .byte 0                               # End Of Children Mark
+  .byte 4                               # Abbrev [4] 0x48:0x36 DW_TAG_subprogram
+  .byte 1                               # DW_AT_low_pc
+  .long .Lfunc_end1-.Lfunc_begin1       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .byte 5                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 7                               # DW_AT_decl_line
+  .long 126                             # DW_AT_type
+                                        # DW_AT_external
+  .byte 3                               # Abbrev [3] 0x57:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 85
+  .byte 9                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 7                               # DW_AT_decl_line
+  .long 126                             # DW_AT_type
+  .byte 3                               # Abbrev [3] 0x61:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 84
+  .byte 10                              # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 7                               # DW_AT_decl_line
+  .long 135                             # DW_AT_type
+  .byte 5                               # Abbrev [5] 0x6b:0x9 DW_TAG_variable
+  .byte 0                               # DW_AT_location
+  .byte 7                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 8                               # DW_AT_decl_line
+  .long 126                             # DW_AT_type
+  .byte 5                               # Abbrev [5] 0x74:0x9 DW_TAG_variable
+  .byte 1                               # DW_AT_location
+  .byte 8                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 9                               # DW_AT_decl_line
+  .long 126                             # DW_AT_type
+  .byte 0                               # End Of Children Mark
+  .byte 6                               # Abbrev [6] 0x7e:0x4 DW_TAG_base_type
+  .byte 6                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 7                               # Abbrev [7] 0x82:0x5 DW_TAG_pointer_type
+  .long 126                             # DW_AT_type
+  .byte 7                               # Abbrev [7] 0x87:0x5 DW_TAG_pointer_type
+  .long 140                             # DW_AT_type
+  .byte 7                               # Abbrev [7] 0x8c:0x5 DW_TAG_pointer_type
+  .long 145                             # DW_AT_type
+  .byte 6                               # Abbrev [6] 0x91:0x4 DW_TAG_base_type
+  .byte 11                              # DW_AT_name
+  .byte 6                               # DW_AT_encoding
+  .byte 1                               # DW_AT_byte_size
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 52                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Linfo_string0:
+  .asciz  "clang version 15.0.0" # string offset=0
+.Linfo_string1:
+  .asciz  "main.cpp"                      # string offset=134
+.Linfo_string2:
+  .asciz  "/testLocListMultiple" # string offset=143
+.Linfo_string3:
+  .asciz  "_Z3usePiS_"                    # string offset=200
+.Linfo_string4:
+  .asciz  "use"                           # string offset=211
+.Linfo_string5:
+  .asciz  "main"                          # string offset=215
+.Linfo_string6:
+  .asciz  "int"                           # string offset=220
+.Linfo_string7:
+  .asciz  "x"                             # string offset=224
+.Linfo_string8:
+  .asciz  "y"                             # string offset=226
+.Linfo_string9:
+  .asciz  "argc"                          # string offset=228
+.Linfo_string10:
+  .asciz  "argv"                          # string offset=233
+.Linfo_string11:
+  .asciz  "char"                          # string offset=238
+  .section  .debug_str_offsets,"",@progbits
+  .long .Linfo_string0
+  .long .Linfo_string1
+  .long .Linfo_string2
+  .long .Linfo_string3
+  .long .Linfo_string4
+  .long .Linfo_string5
+  .long .Linfo_string6
+  .long .Linfo_string7
+  .long .Linfo_string8
+  .long .Linfo_string9
+  .long .Linfo_string10
+  .long .Linfo_string11
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad .Lfunc_begin0
+  .quad .Lfunc_begin1
+.Ldebug_addr_end0:
+  .ident  "clang version 15.0.0"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/dwarf5-debug-info-dwarf4-debug-line.s

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=4 -filetype=obj -triple x86_64-unknown-linux %s -o %t1.o
+# RUN: %clang %cflags -dwarf-5 %t1.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-line %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-line %t.bolt | FileCheck --check-prefix=POSTCHECK %s
+
+# This test checks that .debug_line gets generated correctly when .debug_info is DWARF5, and .debug_line is DWARF4.
+
+# PRECHECK: version: 4
+# PRECHECK: file_names[  1]:
+# PRECHECK-NEXT: name: "main.cpp"
+# PRECHECK-NEXT: dir_index: 0
+# PRECHECK-NEXT: mod_time: 0x00000000
+# PRECHECK-NEXT: length: 0x00000000
+
+# POSTCHECK: version: 4
+# POSTCHECK: file_names[  1]:
+# POSTCHECK-NEXT: name: "main.cpp"
+# POSTCHECK-NEXT: dir_index: 0
+# POSTCHECK-NEXT: mod_time: 0x00000000
+# POSTCHECK-NEXT: length: 0x00000000
+
+# int main() {
+#    return 0;
+# }
+
+
+  .file "main.cpp"
+  .text
+.Ltext0:
+  .globl  main
+  .type main, @function
+main:
+.LFB0:
+  .file 1 "main.cpp"
+  .loc 1 1 12
+  .cfi_startproc
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset 6, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register 6
+  .loc 1 2 10
+  movl  $0, %eax
+  .loc 1 3 1
+  popq  %rbp
+  .cfi_def_cfa 7, 8
+  ret
+  .cfi_endproc
+.LFE0:
+  .size main, .-main
+.Letext0:
+  .section  .debug_info,"",@progbits
+.Ldebug_info0:
+  .long 0x50
+  .value  0x5
+  .byte 0x1
+  .byte 0x8
+  .long .Ldebug_abbrev0
+  .uleb128 0x1
+  .long .LASF0
+  .byte 0x21
+  .long .LASF1
+  .long .LASF2
+  .quad .Ltext0
+  .quad .Letext0-.Ltext0
+  .long .Ldebug_line0
+  .uleb128 0x2
+  .long .LASF3
+  .byte 0x1
+  .byte 0x1
+  .byte 0x5
+  .long 0x4c
+  .quad .LFB0
+  .quad .LFE0-.LFB0
+  .uleb128 0x1
+  .byte 0x9c
+  .uleb128 0x3
+  .byte 0x4
+  .byte 0x5
+  .string "int"
+  .byte 0
+  .section  .debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+  .uleb128 0x1
+  .uleb128 0x11
+  .byte 0x1
+  .uleb128 0x25
+  .uleb128 0xe
+  .uleb128 0x13
+  .uleb128 0xb
+  .uleb128 0x3
+  .uleb128 0xe
+  .uleb128 0x1b
+  .uleb128 0xe
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x12
+  .uleb128 0x7
+  .uleb128 0x10
+  .uleb128 0x17
+  .byte 0
+  .byte 0
+  .uleb128 0x2
+  .uleb128 0x2e
+  .byte 0
+  .uleb128 0x3f
+  .uleb128 0x19
+  .uleb128 0x3
+  .uleb128 0xe
+  .uleb128 0x3a
+  .uleb128 0xb
+  .uleb128 0x3b
+  .uleb128 0xb
+  .uleb128 0x39
+  .uleb128 0xb
+  .uleb128 0x49
+  .uleb128 0x13
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x12
+  .uleb128 0x7
+  .uleb128 0x40
+  .uleb128 0x18
+  .uleb128 0x7a
+  .uleb128 0x19
+  .byte 0
+  .byte 0
+  .uleb128 0x3
+  .uleb128 0x24
+  .byte 0
+  .uleb128 0xb
+  .uleb128 0xb
+  .uleb128 0x3e
+  .uleb128 0xb
+  .uleb128 0x3
+  .uleb128 0x8
+  .byte 0
+  .byte 0
+  .byte 0
+  .section  .debug_aranges,"",@progbits
+  .long 0x2c
+  .value  0x2
+  .long .Ldebug_info0
+  .byte 0x8
+  .byte 0
+  .value  0
+  .value  0
+  .quad .Ltext0
+  .quad .Letext0-.Ltext0
+  .quad 0
+  .quad 0
+  .section  .debug_line,"",@progbits
+.Ldebug_line0:
+  .section  .debug_str,"MS",@progbits,1
+.LASF0:
+  .string "GNU C++14 8.5.0 20210514 (Red Hat 8.5.0-3) -mtune=generic -march=x86-64 -g2 -gdwarf-5"
+.LASF1:
+  .string "main.cpp"
+.LASF3:
+  .string "main"
+.LASF2:
+  .string "."
+  .ident  "GCC: (GNU) 8.5.0 20210514 (Red Hat 8.5.0-3)"
+  .section  .note.GNU-stack,"",@progbits

bolt/test/X86/dwarf5-debug-line.s

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %s -o %t1.o
+# RUN: %clang %cflags -dwarf-5 %t1.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-line %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-line %t.bolt | FileCheck --check-prefix=POSTCHECK %s
+
+# This test checks that DWARF5 .debug_line is handled correctly.
+
+# PRECHECK: version: 5
+# PRECHECK: include_directories[  0] =  .debug_line_str[0x00000000]
+# PRECHECK-NEXT: file_names[  0]:
+# PRECHECK-NEXT: name:  .debug_line_str[0x00000002] = "main.cpp"
+# PRECHECK-NEXT: dir_index: 0
+# PRECHECK-NEXT: md5_checksum: bb12fec8d002b1f0e06f7dee4604c6cc
+# PRECHECK-NOT: file_names[  1]:
+
+# POSTCHECK: version: 5
+# POSTCHECK: include_directories[  0] =  .debug_line_str[0x00000000]
+# POSTCHECK-NEXT: file_names[  0]:
+# POSTCHECK-NEXT: name:  .debug_line_str[0x00000002] = "main.cpp"
+# POSTCHECK-NEXT: dir_index: 0
+# POSTCHECK-NEXT: md5_checksum: bb12fec8d002b1f0e06f7dee4604c6cc
+# POSTCHECK-NOT: file_names[  1]:
+
+# int main() {
+#    return 0;
+# }
+
+  .text
+  .file "main.cpp"
+  .globl  main                            # -- Begin function main
+  .p2align  4, 0x90
+  .type main,@function
+main:                                   # @main
+.Lfunc_begin0:
+  .file 0 "." "main.cpp" md5 0xbb12fec8d002b1f0e06f7dee4604c6cc
+  .loc  0 1 0                           # main.cpp:1:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset %rbp, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register %rbp
+  movl  $0, -4(%rbp)
+.Ltmp0:
+  .loc  0 2 3 prologue_end              # main.cpp:2:3
+  xorl  %eax, %eax
+  popq  %rbp
+  .cfi_def_cfa %rsp, 8
+  retq
+.Ltmp1:
+.Lfunc_end0:
+  .size main, .Lfunc_end0-main
+  .cfi_endproc
+                                        # -- End function
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 0                               # DW_CHILDREN_no
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 1                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .byte 1                               # Abbrev [1] 0xc:0x2b DW_TAG_compile_unit
+  .byte 0                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 1                               # DW_AT_name
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .byte 2                               # DW_AT_comp_dir
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+  .byte 2                               # Abbrev [2] 0x23:0xf DW_TAG_subprogram
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 86
+  .byte 3                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 50                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 3                               # Abbrev [3] 0x32:0x4 DW_TAG_base_type
+  .byte 4                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 24                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Linfo_string0:
+  .asciz  "clang version 15.0.0" # string offset=0
+.Linfo_string1:
+  .asciz  "main.cpp"                      # string offset=134
+.Linfo_string2:
+  .asciz  "." # string offset=143
+.Linfo_string3:
+  .asciz  "main"                          # string offset=180
+.Linfo_string4:
+  .asciz  "int"                           # string offset=185
+  .section  .debug_str_offsets,"",@progbits
+  .long .Linfo_string0
+  .long .Linfo_string1
+  .long .Linfo_string2
+  .long .Linfo_string3
+  .long .Linfo_string4
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad .Lfunc_begin0
+.Ldebug_addr_end0:
+  .ident  "clang version 15.0.0"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/dwarf5-debug-loclists.s

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %s -o %t1.o
+# RUN: %clang %cflags -dwarf-5 %t1.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-addr %t.bolt > %t.txt
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt >> %t.txt
+# RUN: cat %t.txt | FileCheck --check-prefix=POSTCHECK %s
+
+# This tests checks that re-writing of .debug_loclists is handled correctly.
+
+# PRECHECK: version = 0x0005
+# PRECHECK: DW_AT_loclists_base [DW_FORM_sec_offset] (0x0000000c)
+# PRECHECK-EMPTY:
+# PRECHECK: DW_TAG_variable
+# PRECHECK: DW_AT_location [DW_FORM_loclistx]
+# PRECHECK-SAME: indexed (0x0)
+# PRECHECK-SAME: loclist = 0x00000010
+
+# POSTCHECK: Addrs: [
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR:]]
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR2:]]
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_AT_loclists_base [DW_FORM_sec_offset] (0x0000000c)
+# POSTCHECK: DW_AT_rnglists_base [DW_FORM_sec_offset] (0x0000000c)
+# POSTCHECK: DW_TAG_variable
+# POSTCHECK: DW_AT_location [DW_FORM_loclistx]
+# POSTCHECK-SAME: indexed (0x0)
+# POSTCHECK-SAME: loclist = 0x00000010
+# POSTCHECK-NEXT: [0x[[#ADDR]]
+# POSTCHECK-SAME: 0x[[#ADDR + 3]]
+# POSTCHECK-NEXT: [0x[[#ADDR2]]
+# POSTCHECK-SAME: 0x[[#ADDR2 + 1]]
+
+# clang++ main.cpp -g -O2 -S
+# void use(int * x) {
+#   *x += 4;
+# }
+#
+# int  main(int argc, char *argv[]) {
+#   int x = argc;
+#   use(&x);
+#   return x;
+# }
+
+  .text
+  .file "main.cpp"
+  .globl  _Z3usePi                        # -- Begin function _Z3usePi
+  .p2align  4, 0x90
+  .type _Z3usePi,@function
+_Z3usePi:                               # @_Z3usePi
+.Lfunc_begin0:
+  .file 0 "testLocList" "main.cpp" md5 0x95a77c95663d823a6228bf928825e8c7
+  .loc  0 1 0                           # main.cpp:1:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  #DEBUG_VALUE: use:x <- $rdi
+  .loc  0 2 4 prologue_end              # main.cpp:2:4
+  addl  $4, (%rdi)
+  .loc  0 3 1                           # main.cpp:3:1
+  retq
+.Ltmp0:
+.Lfunc_end0:
+  .size _Z3usePi, .Lfunc_end0-_Z3usePi
+  .cfi_endproc
+                                        # -- End function
+  .globl  main                            # -- Begin function main
+  .p2align  4, 0x90
+  .type main,@function
+main:                                   # @main
+.Lfunc_begin1:
+  .loc  0 5 0                           # main.cpp:5:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  #DEBUG_VALUE: main:argc <- $edi
+  #DEBUG_VALUE: main:argv <- $rsi
+  #DEBUG_VALUE: main:x <- $edi
+                                        # kill: def $edi killed $edi def $rdi
+  #DEBUG_VALUE: use:x <- undef
+  .loc  0 2 4 prologue_end              # main.cpp:2:4
+  leal  4(%rdi), %eax
+.Ltmp1:
+  #DEBUG_VALUE: main:x <- $eax
+  .loc  0 8 4                           # main.cpp:8:4
+  retq
+.Ltmp2:
+.Lfunc_end1:
+  .size main, .Lfunc_end1-main
+  .cfi_endproc
+                                        # -- End function
+  .section  .debug_loclists,"",@progbits
+  .long .Ldebug_list_header_end0-.Ldebug_list_header_start0 # Length
+.Ldebug_list_header_start0:
+  .short  5                               # Version
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+  .long 1                               # Offset entry count
+.Lloclists_table_base0:
+  .long .Ldebug_loc0-.Lloclists_table_base0
+.Ldebug_loc0:
+  .byte 4                               # DW_LLE_offset_pair
+  .uleb128 .Lfunc_begin1-.Lfunc_begin0    #   starting offset
+  .uleb128 .Ltmp1-.Lfunc_begin0           #   ending offset
+  .byte 1                               # Loc expr size
+  .byte 85                              # super-register DW_OP_reg5
+  .byte 4                               # DW_LLE_offset_pair
+  .uleb128 .Ltmp1-.Lfunc_begin0           #   starting offset
+  .uleb128 .Lfunc_end1-.Lfunc_begin0      #   ending offset
+  .byte 1                               # Loc expr size
+  .byte 80                              # super-register DW_OP_reg0
+  .byte 0                               # DW_LLE_end_of_list
+.Ldebug_list_header_end0:
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .ascii  "\214\001"                      # DW_AT_loclists_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 4                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 110                             # DW_AT_linkage_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 32                              # DW_AT_inline
+  .byte 33                              # DW_FORM_implicit_const
+  .byte 1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 5                               # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 6                               # Abbreviation Code
+  .byte 15                              # DW_TAG_pointer_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 7                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 8                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 9                               # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 10                              # Abbreviation Code
+  .byte 52                              # DW_TAG_variable
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 34                              # DW_FORM_loclistx
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 11                              # Abbreviation Code
+  .byte 29                              # DW_TAG_inlined_subroutine
+  .byte 0                               # DW_CHILDREN_no
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 88                              # DW_AT_call_file
+  .byte 11                              # DW_FORM_data1
+  .byte 89                              # DW_AT_call_line
+  .byte 11                              # DW_FORM_data1
+  .byte 87                              # DW_AT_call_column
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 1                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .byte 1                               # Abbrev [1] 0xc:0x8f DW_TAG_compile_unit
+  .byte 0                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 1                               # DW_AT_name
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .byte 2                               # DW_AT_comp_dir
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end1-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+  .long .Lloclists_table_base0          # DW_AT_loclists_base
+  .byte 2                               # Abbrev [2] 0x27:0x14 DW_TAG_subprogram
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .long 59                              # DW_AT_abstract_origin
+  .byte 3                               # Abbrev [3] 0x33:0x7 DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 85
+  .long 64                              # DW_AT_abstract_origin
+  .byte 0                               # End Of Children Mark
+  .byte 4                               # Abbrev [4] 0x3b:0xe DW_TAG_subprogram
+  .byte 3                               # DW_AT_linkage_name
+  .byte 4                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+                                        # DW_AT_external
+                                        # DW_AT_inline
+  .byte 5                               # Abbrev [5] 0x40:0x8 DW_TAG_formal_parameter
+  .byte 5                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 73                              # DW_AT_type
+  .byte 0                               # End Of Children Mark
+  .byte 6                               # Abbrev [6] 0x49:0x5 DW_TAG_pointer_type
+  .long 78                              # DW_AT_type
+  .byte 7                               # Abbrev [7] 0x4e:0x4 DW_TAG_base_type
+  .byte 6                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 8                               # Abbrev [8] 0x52:0x3a DW_TAG_subprogram
+  .byte 1                               # DW_AT_low_pc
+  .long .Lfunc_end1-.Lfunc_begin1       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .byte 7                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 5                               # DW_AT_decl_line
+  .long 78                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 9                               # Abbrev [9] 0x61:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 85
+  .byte 8                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 5                               # DW_AT_decl_line
+  .long 78                              # DW_AT_type
+  .byte 9                               # Abbrev [9] 0x6b:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 84
+  .byte 9                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 5                               # DW_AT_decl_line
+  .long 140                             # DW_AT_type
+  .byte 10                              # Abbrev [10] 0x75:0x9 DW_TAG_variable
+  .byte 0                               # DW_AT_location
+  .byte 5                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 6                               # DW_AT_decl_line
+  .long 78                              # DW_AT_type
+  .byte 11                              # Abbrev [11] 0x7e:0xd DW_TAG_inlined_subroutine
+  .long 59                              # DW_AT_abstract_origin
+  .byte 1                               # DW_AT_low_pc
+  .long .Ltmp1-.Lfunc_begin1            # DW_AT_high_pc
+  .byte 0                               # DW_AT_call_file
+  .byte 7                               # DW_AT_call_line
+  .byte 4                               # DW_AT_call_column
+  .byte 0                               # End Of Children Mark
+  .byte 6                               # Abbrev [6] 0x8c:0x5 DW_TAG_pointer_type
+  .long 145                             # DW_AT_type
+  .byte 6                               # Abbrev [6] 0x91:0x5 DW_TAG_pointer_type
+  .long 150                             # DW_AT_type
+  .byte 7                               # Abbrev [7] 0x96:0x4 DW_TAG_base_type
+  .byte 10                              # DW_AT_name
+  .byte 6                               # DW_AT_encoding
+  .byte 1                               # DW_AT_byte_size
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 48                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Linfo_string0:
+  .asciz  "clang version 15.0.0)" # string offset=0
+.Linfo_string1:
+  .asciz  "main.cpp"                      # string offset=134
+.Linfo_string2:
+  .asciz  "/testLocList" # string offset=143
+.Linfo_string3:
+  .asciz  "_Z3usePi"                      # string offset=192
+.Linfo_string4:
+  .asciz  "use"                           # string offset=201
+.Linfo_string5:
+  .asciz  "x"                             # string offset=205
+.Linfo_string6:
+  .asciz  "int"                           # string offset=207
+.Linfo_string7:
+  .asciz  "main"                          # string offset=211
+.Linfo_string8:
+  .asciz  "argc"                          # string offset=216
+.Linfo_string9:
+  .asciz  "argv"                          # string offset=221
+.Linfo_string10:
+  .asciz  "char"                          # string offset=226
+  .section  .debug_str_offsets,"",@progbits
+  .long .Linfo_string0
+  .long .Linfo_string1
+  .long .Linfo_string2
+  .long .Linfo_string3
+  .long .Linfo_string4
+  .long .Linfo_string5
+  .long .Linfo_string6
+  .long .Linfo_string7
+  .long .Linfo_string8
+  .long .Linfo_string9
+  .long .Linfo_string10
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad .Lfunc_begin0
+  .quad .Lfunc_begin1
+.Ldebug_addr_end0:
+  .ident  "clang version 15.0.0"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/dwarf5-label-low-pc.s

+
+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %s -o %tmain.o
+# RUN: %clang %cflags -dwarf-5 %tmain.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+
+# RUN: llvm-dwarfdump --show-form --verbose --debug-addr %t.bolt > %t.txt
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt >> %t.txt
+
+# This test checks that we correctly handle DW_AT_low_pc [DW_FORM_addrx] that is part of DW_TAG_label.
+
+# PRECHECK: version = 0x0005
+# PRECHECK: DW_TAG_label
+# PRECHECK-NEXT: DW_AT_name
+# PRECHECK-NEXT: DW_AT_decl_file
+# PRECHECK-NEXT: DW_AT_decl_line
+# PRECHECK-NEXT:DW_AT_low_pc [DW_FORM_addrx]  (indexed (00000001)
+# PRECHECK: DW_TAG_label
+# PRECHECK-NEXT: DW_AT_name
+# PRECHECK-NEXT: DW_AT_decl_file
+# PRECHECK-NEXT: DW_AT_decl_line
+# PRECHECK-NEXT:DW_AT_low_pc [DW_FORM_addrx]  (indexed (00000002)
+
+
+# POSTCHECK: Addrs: [
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR:]]
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR2:]]
+
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_TAG_label
+# POSTCHECK-NEXT: DW_AT_name
+# POSTCHECK-NEXT: DW_AT_decl_file
+# POSTCHECK-NEXT: DW_AT_decl_line
+# POSTCHECK-NEXT:
+# POSTCHECK-NEXT:DW_AT_low_pc [DW_FORM_addrx]  (indexed (00000002)
+# POSTCHECK-SAME: [0x[[#ADDR]]
+# POSTCHECK: DW_TAG_label
+# POSTCHECK-NEXT: DW_AT_name
+# POSTCHECK-NEXT: DW_AT_decl_file
+# POSTCHECK-NEXT: DW_AT_decl_line
+# POSTCHECK-NEXT:
+# POSTCHECK-NEXT:DW_AT_low_pc [DW_FORM_addrx]  (indexed (00000003)
+# POSTCHECK-SAME: [0x[[#ADDR2]]
+
+# clang++ main.cpp -g -S
+# int main() {
+#   int a = 4;
+#   if (a == 5)
+#     goto LABEL1;
+#   else
+#     goto LABEL2;
+#   LABEL1:a++;
+#   LABEL2:a--;
+#   return 0;
+# }
+
+  .text
+  .file "main.cpp"
+  .globl  main                            # -- Begin function main
+  .p2align  4, 0x90
+  .type main,@function
+main:                                   # @main
+.Lfunc_begin0:
+  .file 0 "/testLabel" "main.cpp" md5 0xa0bd66020d06f1303de7008e3c542050
+  .loc  0 1 0                           # main.cpp:1:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset %rbp, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register %rbp
+  movl  $0, -4(%rbp)
+.Ltmp0:
+  .loc  0 2 7 prologue_end              # main.cpp:2:7
+  movl  $4, -8(%rbp)
+.Ltmp1:
+  .loc  0 3 9                           # main.cpp:3:9
+  cmpl  $5, -8(%rbp)
+.Ltmp2:
+  .loc  0 3 7 is_stmt 0                 # main.cpp:3:7
+  jne .LBB0_2
+# %bb.1:                                # %if.then
+.Ltmp3:
+  .loc  0 4 5 is_stmt 1                 # main.cpp:4:5
+  jmp .LBB0_3
+.LBB0_2:                                # %if.else
+  .loc  0 6 5                           # main.cpp:6:5
+  jmp .LBB0_4
+.Ltmp4:
+.LBB0_3:                                # %LABEL1
+  #DEBUG_LABEL: main:LABEL1
+  .loc  0 7 11                          # main.cpp:7:11
+  movl  -8(%rbp), %eax
+  addl  $1, %eax
+  movl  %eax, -8(%rbp)
+.LBB0_4:                                # %LABEL2
+.Ltmp5:
+  #DEBUG_LABEL: main:LABEL2
+  .loc  0 8 11                          # main.cpp:8:11
+  movl  -8(%rbp), %eax
+  addl  $-1, %eax
+  movl  %eax, -8(%rbp)
+  .loc  0 9 3                           # main.cpp:9:3
+  xorl  %eax, %eax
+  popq  %rbp
+  .cfi_def_cfa %rsp, 8
+  retq
+.Ltmp6:
+.Lfunc_end0:
+  .size main, .Lfunc_end0-main
+  .cfi_endproc
+                                        # -- End function
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 52                              # DW_TAG_variable
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 4                               # Abbreviation Code
+  .byte 10                              # DW_TAG_label
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 5                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 1                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .byte 1                               # Abbrev [1] 0xc:0x41 DW_TAG_compile_unit
+  .byte 0                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 1                               # DW_AT_name
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .byte 2                               # DW_AT_comp_dir
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+  .byte 2                               # Abbrev [2] 0x23:0x25 DW_TAG_subprogram
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 86
+  .byte 3                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 72                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 3                               # Abbrev [3] 0x32:0xb DW_TAG_variable
+  .byte 2                               # DW_AT_location
+  .byte 145
+  .byte 120
+  .byte 5                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 2                               # DW_AT_decl_line
+  .long 72                              # DW_AT_type
+  .byte 4                               # Abbrev [4] 0x3d:0x5 DW_TAG_label
+  .byte 6                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 7                               # DW_AT_decl_line
+  .byte 1                               # DW_AT_low_pc
+  .byte 4                               # Abbrev [4] 0x42:0x5 DW_TAG_label
+  .byte 7                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 8                               # DW_AT_decl_line
+  .byte 2                               # DW_AT_low_pc
+  .byte 0                               # End Of Children Mark
+  .byte 5                               # Abbrev [5] 0x48:0x4 DW_TAG_base_type
+  .byte 4                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 36                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Linfo_string0:
+  .asciz  "clang version 15.0.0" # string offset=0
+.Linfo_string1:
+  .asciz  "main.cpp"                      # string offset=134
+.Linfo_string2:
+  .asciz  "/testLabel" # string offset=143
+.Linfo_string3:
+  .asciz  "main"                          # string offset=190
+.Linfo_string4:
+  .asciz  "int"                           # string offset=195
+.Linfo_string5:
+  .asciz  "a"                             # string offset=199
+.Linfo_string6:
+  .asciz  "LABEL1"                        # string offset=201
+.Linfo_string7:
+  .asciz  "LABEL2"                        # string offset=208
+  .section  .debug_str_offsets,"",@progbits
+  .long .Linfo_string0
+  .long .Linfo_string1
+  .long .Linfo_string2
+  .long .Linfo_string3
+  .long .Linfo_string4
+  .long .Linfo_string5
+  .long .Linfo_string6
+  .long .Linfo_string7
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad .Lfunc_begin0
+  .quad .Ltmp4
+  .quad .Ltmp5
+.Ldebug_addr_end0:
+  .ident  "clang version 15.0.0"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/dwarf5-locexpr-addrx.s

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %s -o %tmain.o
+# RUN: %clang %cflags -dwarf-5 %tmain.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt | FileCheck --check-prefix=POSTCHECK %s
+
+# This test checks that we correctly encode new index into .debug_addr section
+# from DW_AT_location [DW_FORM_exprloc]  (DW_OP_addrx 0x#)
+
+# PRECHECK: version = 0x0005
+# PRECHECK: DW_TAG_variable
+# PRECHECK: DW_AT_location [DW_FORM_exprloc]  (DW_OP_addrx 0x0)
+# PRECHECK: DW_TAG_variable
+# PRECHECK: DW_AT_location [DW_FORM_exprloc]  (DW_OP_addrx 0x1)
+# PRECHECK-EMPTY:
+
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_TAG_variable
+# POSTCHECK: DW_AT_location [DW_FORM_exprloc]  (DW_OP_addrx 0x3)
+# POSTCHECK-EMPTY:
+# POSTCHECK: DW_TAG_variable
+# POSTCHECK: DW_AT_location [DW_FORM_exprloc]  (DW_OP_addrx 0x4)
+# POSTCHECK-EMPTY:
+
+# clang++ main.cpp -g -O2
+# void use(int * x, int * y) {
+# *x += 4;
+# *y -= 2;
+# }
+#
+# int x = 0;
+# int y = 1;
+# int  main(int argc, char *argv[]) {
+#    x = argc;
+#    y = argc + 3;
+#    use(&x, &y);
+#    return x + y;
+# }
+
+  .text
+  .file "main.cpp"
+  .file 0 "/testLocExprLoc" "main.cpp" md5 0xd4fd79ce0087c4cefd089752bf2182c6
+  .globl  _Z3usePiS_                      # -- Begin function _Z3usePiS_
+  .p2align  4, 0x90
+  .type _Z3usePiS_,@function
+_Z3usePiS_:                             # @_Z3usePiS_
+.Lfunc_begin0:
+  .loc  0 1 0                           # main.cpp:1:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  #DEBUG_VALUE: use:x <- $rdi
+  #DEBUG_VALUE: use:y <- $rsi
+  .loc  0 2 4 prologue_end              # main.cpp:2:4
+  addl  $4, (%rdi)
+  .loc  0 3 4                           # main.cpp:3:4
+  addl  $-2, (%rsi)
+  .loc  0 4 1                           # main.cpp:4:1
+  retq
+.Ltmp0:
+.Lfunc_end0:
+  .size _Z3usePiS_, .Lfunc_end0-_Z3usePiS_
+  .cfi_endproc
+                                        # -- End function
+  .globl  main                            # -- Begin function main
+  .p2align  4, 0x90
+  .type main,@function
+main:                                   # @main
+.Lfunc_begin1:
+  .loc  0 8 0                           # main.cpp:8:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  #DEBUG_VALUE: main:argc <- $edi
+  #DEBUG_VALUE: main:argv <- $rsi
+                                        # kill: def $edi killed $edi def $rdi
+  .loc  0 2 4 prologue_end              # main.cpp:2:4
+  leal  4(%rdi), %eax
+  movl  %eax, x(%rip)
+.Ltmp1:
+  #DEBUG_VALUE: use:x <- undef
+  .loc  0 3 4                           # main.cpp:3:4
+  leal  1(%rdi), %eax
+  movl  %eax, y(%rip)
+.Ltmp2:
+  #DEBUG_VALUE: use:y <- undef
+  .loc  0 12 13                         # main.cpp:12:13
+  leal  (%rdi,%rdi), %eax
+  addl  $5, %eax
+  .loc  0 12 4 is_stmt 0                # main.cpp:12:4
+  retq
+.Ltmp3:
+.Lfunc_end1:
+  .size main, .Lfunc_end1-main
+  .cfi_endproc
+                                        # -- End function
+  .type x,@object                       # @x
+  .bss
+  .globl  x
+  .p2align  2
+x:
+  .long 0                               # 0x0
+  .size x, 4
+
+  .type y,@object                       # @y
+  .data
+  .globl  y
+  .p2align  2
+y:
+  .long 1                               # 0x1
+  .size y, 4
+
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 52                              # DW_TAG_variable
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 4                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 5                               # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 6                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 110                             # DW_AT_linkage_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 32                              # DW_AT_inline
+  .byte 33                              # DW_FORM_implicit_const
+  .byte 1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 7                               # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 8                               # Abbreviation Code
+  .byte 15                              # DW_TAG_pointer_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 9                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 10                              # Abbreviation Code
+  .byte 5                               # DW_TAG_formal_parameter
+  .byte 0                               # DW_CHILDREN_no
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 11                              # Abbreviation Code
+  .byte 29                              # DW_TAG_inlined_subroutine
+  .byte 0                               # DW_CHILDREN_no
+  .byte 49                              # DW_AT_abstract_origin
+  .byte 19                              # DW_FORM_ref4
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 88                              # DW_AT_call_file
+  .byte 11                              # DW_FORM_data1
+  .byte 89                              # DW_AT_call_line
+  .byte 11                              # DW_FORM_data1
+  .byte 87                              # DW_AT_call_column
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 1                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .byte 1                               # Abbrev [1] 0xc:0xa7 DW_TAG_compile_unit
+  .byte 0                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 1                               # DW_AT_name
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .byte 2                               # DW_AT_comp_dir
+  .byte 2                               # DW_AT_low_pc
+  .long .Lfunc_end1-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+  .byte 2                               # Abbrev [2] 0x23:0xb DW_TAG_variable
+  .byte 3                               # DW_AT_name
+  .long 46                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 0                               # DW_AT_decl_file
+  .byte 6                               # DW_AT_decl_line
+  .byte 2                               # DW_AT_location
+  .byte 161
+  .byte 0
+  .byte 3                               # Abbrev [3] 0x2e:0x4 DW_TAG_base_type
+  .byte 4                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 2                               # Abbrev [2] 0x32:0xb DW_TAG_variable
+  .byte 5                               # DW_AT_name
+  .long 46                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 0                               # DW_AT_decl_file
+  .byte 7                               # DW_AT_decl_line
+  .byte 2                               # DW_AT_location
+  .byte 161
+  .byte 1
+  .byte 4                               # Abbrev [4] 0x3d:0x1b DW_TAG_subprogram
+  .byte 2                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .long 88                              # DW_AT_abstract_origin
+  .byte 5                               # Abbrev [5] 0x49:0x7 DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 85
+  .long 93                              # DW_AT_abstract_origin
+  .byte 5                               # Abbrev [5] 0x50:0x7 DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 84
+  .long 101                             # DW_AT_abstract_origin
+  .byte 0                               # End Of Children Mark
+  .byte 6                               # Abbrev [6] 0x58:0x16 DW_TAG_subprogram
+  .byte 6                               # DW_AT_linkage_name
+  .byte 7                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+                                        # DW_AT_external
+                                        # DW_AT_inline
+  .byte 7                               # Abbrev [7] 0x5d:0x8 DW_TAG_formal_parameter
+  .byte 3                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 110                             # DW_AT_type
+  .byte 7                               # Abbrev [7] 0x65:0x8 DW_TAG_formal_parameter
+  .byte 5                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 110                             # DW_AT_type
+  .byte 0                               # End Of Children Mark
+  .byte 8                               # Abbrev [8] 0x6e:0x5 DW_TAG_pointer_type
+  .long 46                              # DW_AT_type
+  .byte 9                               # Abbrev [9] 0x73:0x31 DW_TAG_subprogram
+  .byte 3                               # DW_AT_low_pc
+  .long .Lfunc_end1-.Lfunc_begin1       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .byte 8                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 8                               # DW_AT_decl_line
+  .long 46                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 10                              # Abbrev [10] 0x82:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 85
+  .byte 9                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 8                               # DW_AT_decl_line
+  .long 46                              # DW_AT_type
+  .byte 10                              # Abbrev [10] 0x8c:0xa DW_TAG_formal_parameter
+  .byte 1                               # DW_AT_location
+  .byte 84
+  .byte 10                              # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 8                               # DW_AT_decl_line
+  .long 164                             # DW_AT_type
+  .byte 11                              # Abbrev [11] 0x96:0xd DW_TAG_inlined_subroutine
+  .long 88                              # DW_AT_abstract_origin
+  .byte 3                               # DW_AT_low_pc
+  .long .Ltmp2-.Lfunc_begin1            # DW_AT_high_pc
+  .byte 0                               # DW_AT_call_file
+  .byte 11                              # DW_AT_call_line
+  .byte 4                               # DW_AT_call_column
+  .byte 0                               # End Of Children Mark
+  .byte 8                               # Abbrev [8] 0xa4:0x5 DW_TAG_pointer_type
+  .long 169                             # DW_AT_type
+  .byte 8                               # Abbrev [8] 0xa9:0x5 DW_TAG_pointer_type
+  .long 174                             # DW_AT_type
+  .byte 3                               # Abbrev [3] 0xae:0x4 DW_TAG_base_type
+  .byte 11                              # DW_AT_name
+  .byte 6                               # DW_AT_encoding
+  .byte 1                               # DW_AT_byte_size
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 52                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Linfo_string0:
+  .asciz  "clang version 15.0.0" # string offset=0
+.Linfo_string1:
+  .asciz  "main.cpp"                      # string offset=134
+.Linfo_string2:
+  .asciz  "/testLocExprLoc" # string offset=143
+.Linfo_string3:
+  .asciz  "x"                             # string offset=195
+.Linfo_string4:
+  .asciz  "int"                           # string offset=197
+.Linfo_string5:
+  .asciz  "y"                             # string offset=201
+.Linfo_string6:
+  .asciz  "_Z3usePiS_"                    # string offset=203
+.Linfo_string7:
+  .asciz  "use"                           # string offset=214
+.Linfo_string8:
+  .asciz  "main"                          # string offset=218
+.Linfo_string9:
+  .asciz  "argc"                          # string offset=223
+.Linfo_string10:
+  .asciz  "argv"                          # string offset=228
+.Linfo_string11:
+  .asciz  "char"                          # string offset=233
+  .section  .debug_str_offsets,"",@progbits
+  .long .Linfo_string0
+  .long .Linfo_string1
+  .long .Linfo_string2
+  .long .Linfo_string3
+  .long .Linfo_string4
+  .long .Linfo_string5
+  .long .Linfo_string6
+  .long .Linfo_string7
+  .long .Linfo_string8
+  .long .Linfo_string9
+  .long .Linfo_string10
+  .long .Linfo_string11
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad x
+  .quad y
+  .quad .Lfunc_begin0
+  .quad .Lfunc_begin1
+.Ldebug_addr_end0:
+  .ident  "clang version 15.0.0"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/dwarf5-lowpc-highpc-convert.s

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %s -o %t1.o
+# RUN: %clang %cflags -dwarf-5 %t1.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-addr %t.bolt > %t.txt
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt >> %t.txt
+# RUN: cat %t.txt | FileCheck --check-prefix=POSTCHECK %s
+
+# This tests checks that DW_AT_low_pc/DW_AT_high_pc is converted to DW_AT_low_pc/DW_AT_ranges.
+# Checks that DW_AT_rnglists_base is inserted, and that correct address is used.
+
+# PRECHECK: version = 0x0005
+# PRECHECK: DW_AT_low_pc
+# PRECHECK-SAME: DW_FORM_addrx
+# PRECHECK-SAME: (00000000)
+# PRECHECK-NEXT: DW_AT_high_pc [DW_FORM_data4]  (0x0000000f)
+# PRECHECK-NEXT: DW_AT_addr_base [DW_FORM_sec_offset] (0x00000008)
+
+# POSTCHECK: Addrs: [
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR:]]
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_AT_low_pc
+# POSTCHECK-SAME: DW_FORM_addrx
+# POSTCHECK-SAME: (00000001)
+# POSTCHECK-SAME: address = 0x0000000000000000
+# POSTCHECK-NEXT: DW_AT_ranges
+# POSTCHECK-SAME: DW_FORM_rnglistx
+# POSTCHECK-SAME: (0x0)
+# POSTCHECK-SAME: rangelist = 0x00000014
+# POSTCHECK-NEXT: [
+# POSTCHECK-SAME: 0x[[#ADDR]]
+# POSTCHECK-SAME: 0x[[#ADDR + 15]]
+# POSTCHECK-NEXT: DW_AT_addr_base [DW_FORM_sec_offset]  (0x00000008)
+# POSTCHECK-NEXT: DW_AT_rnglists_base [DW_FORM_sec_offset]  (0x0000000c)
+
+# int main() {
+#    return 0;
+# }
+
+  .text
+  .file "main.cpp"
+  .globl  main                            # -- Begin function main
+  .p2align  4, 0x90
+  .type main,@function
+main:                                   # @main
+.Lfunc_begin0:
+  .file 0 "." "main.cpp" md5 0xbb12fec8d002b1f0e06f7dee4604c6cc
+  .loc  0 1 0                           # main.cpp:1:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset %rbp, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register %rbp
+  movl  $0, -4(%rbp)
+.Ltmp0:
+  .loc  0 2 3 prologue_end              # main.cpp:2:3
+  xorl  %eax, %eax
+  popq  %rbp
+  .cfi_def_cfa %rsp, 8
+  retq
+.Ltmp1:
+.Lfunc_end0:
+  .size main, .Lfunc_end0-main
+  .cfi_endproc
+                                        # -- End function
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 0                               # DW_CHILDREN_no
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 1                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .byte 1                               # Abbrev [1] 0xc:0x2b DW_TAG_compile_unit
+  .byte 0                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 1                               # DW_AT_name
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .byte 2                               # DW_AT_comp_dir
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+  .byte 2                               # Abbrev [2] 0x23:0xf DW_TAG_subprogram
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 86
+  .byte 3                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 50                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 3                               # Abbrev [3] 0x32:0x4 DW_TAG_base_type
+  .byte 4                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 24                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Linfo_string0:
+  .asciz  "clang version 15.0.0" # string offset=0
+.Linfo_string1:
+  .asciz  "main.cpp"                      # string offset=134
+.Linfo_string2:
+  .asciz  "." # string offset=143
+.Linfo_string3:
+  .asciz  "main"                          # string offset=180
+.Linfo_string4:
+  .asciz  "int"                           # string offset=185
+  .section  .debug_str_offsets,"",@progbits
+  .long .Linfo_string0
+  .long .Linfo_string1
+  .long .Linfo_string2
+  .long .Linfo_string3
+  .long .Linfo_string4
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad .Lfunc_begin0
+.Ldebug_addr_end0:
+  .ident  "clang version 15.0.0"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/dwarf5-rangeoffset-to-rangeindex.s

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %s -o %t1.o
+# RUN: %clang %cflags -dwarf-5 %t1.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-addr %t.bolt > %t.txt
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt >> %t.txt
+# RUN: cat %t.txt | FileCheck --check-prefix=POSTCHECK %s
+
+# This tests conversion for DWARF5 ranges DW_AT_ranges [DW_FORM_sec_offset] to DW_AT_ranges [DW_FORM_rnglistx]
+
+# PRECHECK: version = 0x0005
+# PRECHECK: DW_AT_ranges [DW_FORM_sec_offset]
+
+# POSTCHECK: Addrs: [
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR:]]
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR1:]]
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK-SAME: (indexed (0x0) rangelist = 0x00000018
+# POSTCHECK-NEXT: [0x[[#ADDR]], 0x[[#ADDR + 11]]
+# POSTCHECK-NEXT: [0x[[#ADDR1]], 0x[[#ADDR1 + 11]]
+
+# int foo() {
+#   return 3;
+# }
+#
+# int main() {
+#   return foo();
+# }
+
+  .file "main.cpp"
+  .text
+.Ltext0:
+  .file 0 "/testRangeOffsetToRangeX" "main.cpp"
+  .section  .text._Z3foov,"ax",@progbits
+  .globl  _Z3foov
+  .type _Z3foov, @function
+_Z3foov:
+.LFB0:
+  .file 1 "main.cpp"
+  .loc 0 1 11
+  .cfi_startproc
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset 6, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register 6
+  .loc 0 2 10
+  movl  $3, %eax
+  .loc 0 3 1
+  popq  %rbp
+  .cfi_def_cfa 7, 8
+  ret
+  .cfi_endproc
+.LFE0:
+  .size _Z3foov, .-_Z3foov
+  .section  .text.main,"ax",@progbits
+  .globl  main
+  .type main, @function
+main:
+.LFB1:
+  .loc 0 5 12
+  .cfi_startproc
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset 6, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register 6
+  .loc 0 6 13
+  call  _Z3foov
+  .loc 0 6 14
+  nop
+  .loc 0 7 1
+  popq  %rbp
+  .cfi_def_cfa 7, 8
+  ret
+  .cfi_endproc
+.LFE1:
+  .size main, .-main
+  .text
+.Letext0:
+  .section  .debug_info,"",@progbits
+.Ldebug_info0:
+  .long 0x6e
+  .value  0x5
+  .byte 0x1
+  .byte 0x8
+  .long .Ldebug_abbrev0
+  .uleb128 0x1
+  .long .LASF2
+  .byte 0x21
+  .long .LASF0
+  .long .LASF1
+  .long .LLRL0
+  .quad 0
+  .long .Ldebug_line0
+  .uleb128 0x2
+  .long .LASF3
+  .byte 0x1
+  .byte 0x5
+  .byte 0x5
+  .long 0x48
+  .quad .LFB1
+  .quad .LFE1-.LFB1
+  .uleb128 0x1
+  .byte 0x9c
+  .uleb128 0x3
+  .byte 0x4
+  .byte 0x5
+  .string "int"
+  .uleb128 0x4
+  .string "foo"
+  .byte 0x1
+  .byte 0x1
+  .byte 0x5
+  .long .LASF4
+  .long 0x48
+  .quad .LFB0
+  .quad .LFE0-.LFB0
+  .uleb128 0x1
+  .byte 0x9c
+  .byte 0
+  .section  .debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+  .uleb128 0x1
+  .uleb128 0x11
+  .byte 0x1
+  .uleb128 0x25
+  .uleb128 0xe
+  .uleb128 0x13
+  .uleb128 0xb
+  .uleb128 0x3
+  .uleb128 0x1f
+  .uleb128 0x1b
+  .uleb128 0x1f
+  .uleb128 0x55
+  .uleb128 0x17
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x10
+  .uleb128 0x17
+  .byte 0
+  .byte 0
+  .uleb128 0x2
+  .uleb128 0x2e
+  .byte 0
+  .uleb128 0x3f
+  .uleb128 0x19
+  .uleb128 0x3
+  .uleb128 0xe
+  .uleb128 0x3a
+  .uleb128 0xb
+  .uleb128 0x3b
+  .uleb128 0xb
+  .uleb128 0x39
+  .uleb128 0xb
+  .uleb128 0x49
+  .uleb128 0x13
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x12
+  .uleb128 0x7
+  .uleb128 0x40
+  .uleb128 0x18
+  .uleb128 0x7c
+  .uleb128 0x19
+  .byte 0
+  .byte 0
+  .uleb128 0x3
+  .uleb128 0x24
+  .byte 0
+  .uleb128 0xb
+  .uleb128 0xb
+  .uleb128 0x3e
+  .uleb128 0xb
+  .uleb128 0x3
+  .uleb128 0x8
+  .byte 0
+  .byte 0
+  .uleb128 0x4
+  .uleb128 0x2e
+  .byte 0
+  .uleb128 0x3f
+  .uleb128 0x19
+  .uleb128 0x3
+  .uleb128 0x8
+  .uleb128 0x3a
+  .uleb128 0xb
+  .uleb128 0x3b
+  .uleb128 0xb
+  .uleb128 0x39
+  .uleb128 0xb
+  .uleb128 0x6e
+  .uleb128 0xe
+  .uleb128 0x49
+  .uleb128 0x13
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x12
+  .uleb128 0x7
+  .uleb128 0x40
+  .uleb128 0x18
+  .uleb128 0x7a
+  .uleb128 0x19
+  .byte 0
+  .byte 0
+  .byte 0
+  .section  .debug_aranges,"",@progbits
+  .long 0x3c
+  .value  0x2
+  .long .Ldebug_info0
+  .byte 0x8
+  .byte 0
+  .value  0
+  .value  0
+  .quad .LFB0
+  .quad .LFE0-.LFB0
+  .quad .LFB1
+  .quad .LFE1-.LFB1
+  .quad 0
+  .quad 0
+  .section  .debug_rnglists,"",@progbits
+.Ldebug_ranges0:
+  .long .Ldebug_ranges3-.Ldebug_ranges2
+.Ldebug_ranges2:
+  .value  0x5
+  .byte 0x8
+  .byte 0
+  .long 0
+.LLRL0:
+  .byte 0x7
+  .quad .LFB0
+  .uleb128 .LFE0-.LFB0
+  .byte 0x7
+  .quad .LFB1
+  .uleb128 .LFE1-.LFB1
+  .byte 0
+.Ldebug_ranges3:
+  .section  .debug_line,"",@progbits
+.Ldebug_line0:
+  .section  .debug_str,"MS",@progbits,1
+.LASF4:
+  .string "_Z3foov"
+.LASF3:
+  .string "main"
+.LASF2:
+  .string "GNU C++17 11.x"
+  .section  .debug_line_str,"MS",@progbits,1
+.LASF0:
+  .string "main.cpp"
+.LASF1:
+  .string "/testRangeOffsetToRangeX"
+  .ident  "GCC: (GNU) 11.x"
+  .section  .note.GNU-stack,"",@progbits

bolt/test/X86/dwarf5-two-loclists.test

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %p/Inputs/dwarf5_main.s -o %tmain.o
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %p/Inputs/dwarf5_helper.s -o %thelper.o
+# RUN: %clang %cflags -dwarf-5 %tmain.o %thelper.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-addr %t.bolt > %t.txt
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt >> %t.txt
+# RUN: cat %t.txt | FileCheck --check-prefix=POSTCHECK %s
+
+# This tests checks that re-writing of .debug_loclists is handled correctly for two CUs,
+# and two loclist entries.
+
+# PRECHECK: version = 0x0005
+# PRECHECK: DW_AT_loclists_base [DW_FORM_sec_offset] (0x0000000c)
+# PRECHECK-EMPTY:
+# PRECHECK: DW_TAG_variable
+# PRECHECK: DW_AT_location [DW_FORM_loclistx]
+# PRECHECK-SAME: indexed (0x0)
+# PRECHECK-SAME: loclist = 0x00000014
+# PRECHECK: DW_AT_location [DW_FORM_loclistx]
+# PRECHECK-SAME: indexed (0x1)
+# PRECHECK-SAME: loclist = 0x00000028
+# PRECHECK: DW_AT_loclists_base [DW_FORM_sec_offset]  (0x00000043)
+# PRECHECK-EMPTY:
+# PRECHECK: DW_TAG_variable
+# PRECHECK: DW_TAG_variable
+# PRECHECK: DW_AT_location [DW_FORM_loclistx]
+# PRECHECK-SAME: indexed (0x0)
+# PRECHECK-SAME: loclist = 0x00000047
+
+# POSTCHECK: Addrs: [
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR:]]
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR2:]]
+# For second CU.
+# POSTCHECK: Addrs: [
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR3:]]
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR4:]]
+
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_AT_loclists_base [DW_FORM_sec_offset] (0x0000000c)
+# POSTCHECK: DW_AT_rnglists_base [DW_FORM_sec_offset] (0x0000000c)
+# POSTCHECK-EMPTY
+# POSTCHECK: DW_TAG_variable
+# POSTCHECK: DW_AT_location [DW_FORM_loclistx]
+# POSTCHECK-SAME: indexed (0x0)
+# POSTCHECK-SAME: loclist = 0x00000014
+# POSTCHECK-NEXT: [0x[[#ADDR]]
+# POSTCHECK-SAME: 0x[[#ADDR + 6]]
+# POSTCHECK-NEXT: [0x[[#ADDR2]]
+# POSTCHECK-SAME: 0x[[#ADDR2 + 6]]
+# POSTCHECK: DW_TAG_variable
+# POSTCHECK: DW_AT_location [DW_FORM_loclistx]
+# POSTCHECK-SAME: indexed (0x1)
+# POSTCHECK-SAME: loclist = 0x00000028
+# POSTCHECK-NEXT: [0x[[#ADDR2]]
+# POSTCHECK-SAME: 0x[[#ADDR2 + 2]]
+
+# Checking second CU
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_AT_loclists_base [DW_FORM_sec_offset] (0x00000043)
+# POSTCHECK: DW_AT_rnglists_base [DW_FORM_sec_offset] (0x00000033)
+# POSTCHECK-EMPTY:
+# POSTCHECK: DW_TAG_variable
+# POSTCHECK: DW_TAG_variable
+# POSTCHECK: DW_AT_location [DW_FORM_loclistx]
+# POSTCHECK-SAME: indexed (0x0)
+# POSTCHECK-SAME: loclist = 0x00000047
+# POSTCHECK-NEXT: [0x[[#ADDR3]]
+# POSTCHECK-SAME: 0x[[#ADDR3 + 3]]
+# POSTCHECK-NEXT: [0x[[#ADDR4]]
+# POSTCHECK-SAME: 0x[[#ADDR4 + 1]]

bolt/test/X86/dwarf5-two-rnglists.test

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %p/Inputs/dwarf5_main.s -o %tmain.o
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %p/Inputs/dwarf5_helper.s -o %thelper.o
+# RUN: %clang %cflags -dwarf-5 %tmain.o %thelper.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-addr %t.bolt > %t.txt
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt >> %t.txt
+# RUN: cat %t.txt | FileCheck --check-prefix=POSTCHECK %s
+
+# This tests checks that re-writing of .debug_rnglists is handled correctly for two CUs,
+# and DW_AT_low_pc/DW_AT_high_pc conversion is handled correctly.
+
+# PRECHECK: version = 0x0005
+# PRECHECK: DW_AT_low_pc [DW_FORM_addrx]
+# PRECHECK: DW_AT_high_pc [DW_FORM_data4]
+# PRECHECK: DW_AT_loclists_base [DW_FORM_sec_offset] (0x0000000c)
+# PRECHECK-EMPTY:
+# PRECHECK: version = 0x0005
+# PRECHECK: DW_AT_low_pc [DW_FORM_addrx]
+# PRECHECK: DW_AT_high_pc [DW_FORM_data4]
+# PRECHECK: DW_AT_loclists_base [DW_FORM_sec_offset]  (0x00000043)
+
+# PRECHECK: DW_TAG_inlined_subroutine
+# PRECHECK-NEXT: DW_AT_abstract_origin
+# PRECHECK-NEXT: DW_AT_low_pc [DW_FORM_addrx]
+# PRECHECK-NEXT: DW_AT_high_pc [DW_FORM_data4] (0x00000003)
+
+# POSTCHECK: Addrs: [
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR:]]
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR1:]]
+# POSTCHECK-NEXT: 0x
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR2:]]
+# For second CU.
+# POSTCHECK: Addrs: [
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR3:]]
+# POSTCHECK-NEXT: 0x[[#%.16x,ADDR4:]]
+
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK-SAME: (indexed (0x0)
+# POSTCHECK-SAME: rangelist = 0x00000018
+# POSTCHECK-NEXT: [
+# POSTCHECK-SAME: 0x[[#ADDR]]
+# POSTCHECK-SAME: 0x[[#ADDR + 7]]
+# POSTCHECK-NEXT: [
+# POSTCHECK-SAME: 0x[[#ADDR1]]
+# POSTCHECK-SAME: 0x[[#ADDR1 + 12]]
+# POSTCHECK-NEXT: DW_AT_addr_base [DW_FORM_sec_offset]  (0x00000008)
+# POSTCHECK-NEXT: DW_AT_loclists_base [DW_FORM_sec_offset]  (0x0000000c)
+# POSTCHECK-NEXT: DW_AT_rnglists_base [DW_FORM_sec_offset]  (0x0000000c)
+# POSTCHECK-EMPTY
+# POSTCHECK: DW_TAG_subprogram
+# POSTCHECK-NEXT: DW_AT_low_pc [DW_FORM_addrx]
+# POSTCHECK-SAME: indexed (00000002)
+# POSTCHECK-SAME: address = 0x0000000000000000
+# POSTCHECK-NEXT: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK-SAME: indexed (0x1)
+# POSTCHECK-SAME: rangelist = 0x0000001f
+# POSTCHECK-NEXT: [0x[[#ADDR]], 0x[[#ADDR + 7]])
+
+# POSTCHECK: DW_TAG_subprogram
+# POSTCHECK-NEXT: DW_AT_low_pc [DW_FORM_addrx]
+# POSTCHECK-SAME: indexed (00000002)
+# POSTCHECK-SAME: address = 0x0000000000000000
+# POSTCHECK-NEXT: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK-SAME: indexed (0x2)
+# POSTCHECK-SAME: rangelist = 0x00000023
+# POSTCHECK-NEXT: [0x[[#ADDR1]], 0x[[#ADDR1 + 12]])
+
+# Checking second CU
+# POSTCHECK: version = 0x0005
+# POSTCHECK: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK-SAME: (indexed (0x0)
+# POSTCHECK-SAME: rangelist = 0x00000043
+# POSTCHECK-NEXT: [0x[[#ADDR3]], 0x[[#ADDR3 + 4]])
+# POSTCHECK-NEXT: [0x[[#ADDR4]], 0x[[#ADDR4 + 4]])
+# POSTCHECK-NEXT: DW_AT_addr_base [DW_FORM_sec_offset]  (0x00000030)
+# POSTCHECK-NEXT: DW_AT_loclists_base [DW_FORM_sec_offset]  (0x00000043)
+# POSTCHECK-NEXT: DW_AT_rnglists_base [DW_FORM_sec_offset]  (0x00000033)
+# POSTCHECK-EMPTY
+
+# POSTCHECK: DW_TAG_subprogram
+# POSTCHECK-NEXT: DW_AT_low_pc [DW_FORM_addrx]
+# POSTCHECK-SAME: indexed (00000002)
+# POSTCHECK-SAME: address = 0x0000000000000000
+# POSTCHECK-NEXT: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK-SAME: indexed (0x1)
+# POSTCHECK-SAME: rangelist = 0x0000004a
+# POSTCHECK-NEXT: [0x[[#ADDR3]], 0x[[#ADDR3 + 4]])
+# POSTCHECK: DW_TAG_subprogram
+# POSTCHECK: DW_TAG_subprogram
+# POSTCHECK-NEXT: DW_AT_low_pc [DW_FORM_addrx]
+# POSTCHECK-SAME: indexed (00000002)
+# POSTCHECK-SAME: address = 0x0000000000000000
+# POSTCHECK-NEXT: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK-SAME: indexed (0x2)
+# POSTCHECK-SAME: rangelist = 0x0000004e
+# POSTCHECK-NEXT: [0x[[#ADDR4]], 0x[[#ADDR4 + 4]])
+
+# POSTCHECK: DW_TAG_inlined_subroutine
+# POSTCHECK-NEXT: DW_AT_abstract_origin
+# POSTCHECK-NEXT: DW_AT_low_pc [DW_FORM_addrx]
+# POSTCHECK-SAME: indexed (00000002)
+# POSTCHECK-SAME: address = 0x0000000000000000
+# POSTCHECK-NEXT: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK-SAME: indexed (0x3)
+# POSTCHECK-SAME: rangelist = 0x00000052
+# POSTCHECK-NEXT: [0x[[#ADDR4]], 0x[[#ADDR4 + 3]])

bolt/test/X86/insert-addr-rnglists_base.s

+# REQUIRES: system-linux
+
+# RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %s -o %t1.o
+# RUN: %clang %cflags -dwarf-5 %t1.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt | FileCheck --check-prefix=POSTCHECK %s
+
+# This test checks we correctly insert DW_AT_addr_base, when converting DW_AT_low_pc into DW_AT_ranges.
+# PRECHECK-NOT: DW_AT_addr_base
+
+# POSTCHECK: DW_AT_ranges [DW_FORM_rnglistx]
+# POSTCHECK: DW_AT_rnglists_base [DW_FORM_sec_offset] (0x0000000c)
+# POSTCHECK-NEXT: DW_AT_addr_base [DW_FORM_sec_offset]  (0x00000008)
+
+# int main() {
+#    return 0;
+# }
+
+
+  .file "main.cpp"
+  .text
+.Ltext0:
+  .globl  main
+  .type main, @function
+main:
+.LFB0:
+  .file 1 "main.cpp"
+  .loc 1 1 12
+  .cfi_startproc
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset 6, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register 6
+  .loc 1 2 10
+  movl  $0, %eax
+  .loc 1 3 1
+  popq  %rbp
+  .cfi_def_cfa 7, 8
+  ret
+  .cfi_endproc
+.LFE0:
+  .size main, .-main
+.Letext0:
+  .section  .debug_info,"",@progbits
+.Ldebug_info0:
+  .long 0x50
+  .value  0x5
+  .byte 0x1
+  .byte 0x8
+  .long .Ldebug_abbrev0
+  .uleb128 0x1
+  .long .LASF0
+  .byte 0x21
+  .long .LASF1
+  .long .LASF2
+  .quad .Ltext0
+  .quad .Letext0-.Ltext0
+  .long .Ldebug_line0
+  .uleb128 0x2
+  .long .LASF3
+  .byte 0x1
+  .byte 0x1
+  .byte 0x5
+  .long 0x4c
+  .quad .LFB0
+  .quad .LFE0-.LFB0
+  .uleb128 0x1
+  .byte 0x9c
+  .uleb128 0x3
+  .byte 0x4
+  .byte 0x5
+  .string "int"
+  .byte 0
+  .section  .debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+  .uleb128 0x1
+  .uleb128 0x11
+  .byte 0x1
+  .uleb128 0x25
+  .uleb128 0xe
+  .uleb128 0x13
+  .uleb128 0xb
+  .uleb128 0x3
+  .uleb128 0xe
+  .uleb128 0x1b
+  .uleb128 0xe
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x12
+  .uleb128 0x7
+  .uleb128 0x10
+  .uleb128 0x17
+  .byte 0
+  .byte 0
+  .uleb128 0x2
+  .uleb128 0x2e
+  .byte 0
+  .uleb128 0x3f
+  .uleb128 0x19
+  .uleb128 0x3
+  .uleb128 0xe
+  .uleb128 0x3a
+  .uleb128 0xb
+  .uleb128 0x3b
+  .uleb128 0xb
+  .uleb128 0x39
+  .uleb128 0xb
+  .uleb128 0x49
+  .uleb128 0x13
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x12
+  .uleb128 0x7
+  .uleb128 0x40
+  .uleb128 0x18
+  .uleb128 0x7a
+  .uleb128 0x19
+  .byte 0
+  .byte 0
+  .uleb128 0x3
+  .uleb128 0x24
+  .byte 0
+  .uleb128 0xb
+  .uleb128 0xb
+  .uleb128 0x3e
+  .uleb128 0xb
+  .uleb128 0x3
+  .uleb128 0x8
+  .byte 0
+  .byte 0
+  .byte 0
+  .section  .debug_aranges,"",@progbits
+  .long 0x2c
+  .value  0x2
+  .long .Ldebug_info0
+  .byte 0x8
+  .byte 0
+  .value  0
+  .value  0
+  .quad .Ltext0
+  .quad .Letext0-.Ltext0
+  .quad 0
+  .quad 0
+  .section  .debug_line,"",@progbits
+.Ldebug_line0:
+  .section  .debug_str,"MS",@progbits,1
+.LASF0:
+  .string "GNU C++14 8.5.0 20210514 (Red Hat 8.5.0-3) -mtune=generic -march=x86-64 -g2 -gdwarf-5"
+.LASF1:
+  .string "main.cpp"
+.LASF3:
+  .string "main"
+.LASF2:
+  .string "."
+  .ident  "GCC: (GNU) 8.5.0 20210514 (Red Hat 8.5.0-3)"
+  .section  .note.GNU-stack,"",@progbits

lldb/test/Shell/SymbolFile/DWARF/x86/DW_TAG_variable-DW_AT_decl_file-DW_AT_abstract_origin-crosscu1.s

 # Check that DW_AT_decl_file of DW_AT_variable which is inherited by
 # DW_AT_abstract_origin from a different DW_TAG_compile_unit is using the
 # DW_TAG_compile_unit->DW_AT_stmt_list where the DW_AT_decl_file is located (and
 # not where the DW_AT_abstract_origin is located).
 # DW_TAG_variable in CU 1 is using DW_AT_decl_file 3.
-# CU 1 has files: 
+# CU 1 has files:
 # file_names[  1]: name: "inlinevarother.h"
 # file_names[  2]: name: "inlinevar1.c"
 # file_names[  3]: name: "inlinevar.h"
-# CU 2 has files: 
+# CU 2 has files:
 # file_names[  1]: name: "inlinevar2.c"
 # file_names[  2]: name: "inlinevar.h"
 
 # UNSUPPORTED: system-darwin, system-windows
 # REQUIRES: target-x86_64
 
-# RUN: %clang_host -o %t %s \
+# RUN: %clang_host -gdwarf-4 -o %t %s \
 # RUN:   %S/Inputs/DW_TAG_variable-DW_AT_decl_file-DW_AT_abstract_origin-crosscu2.s
 
 # RUN: %lldb %t \
 # RUN:   -o 'b other' -o r -o disas -o 'frame variable --show-declaration' \
 # RUN:   -o exit | FileCheck %s
 
 # CHECK: inlinevar.h:2: (int) var = {{.*}}
 # Unfixed LLDB did show only: (int) var = {{.*}}
 
   .text
   .file "inlinevar1.c"
   .file 1 "" "./inlinevarother.h"
   .globl  main                            # -- Begin function main
   .type main,@function
 main:                                   # @main
 .Lfunc_begin1:
   .file 2 "" "inlinevar1.c"
   .loc  2 4 0                           # inlinevar1.c:4:0
 .Ltmp2:
   .file 3 "" "./inlinevar.h"
   .loc  3 2 16 prologue_end             # ./inlinevar.h:2:16
-  movl  $42, %eax 
+  movl  $42, %eax
   pushq %rax
   .loc  3 3 10                          # ./inlinevar.h:3:10
 .Ltmp3:
   .loc  2 5 20                          # inlinevar1.c:5:20
   callq other
   popq  %rcx
   .loc  2 5 19                          # inlinevar1.c:5:19
   addl  %ecx, %eax