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 //===- DWARFDebugFrame.h - Parsing of .debug_frame --------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_DEBUGINFO_DWARF_DWARFDEBUGFRAME_H
 #define LLVM_DEBUGINFO_DWARF_DWARFDEBUGFRAME_H
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/iterator.h"
 #include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/Support/Error.h"
 #include "llvm/TargetParser/Triple.h"
 #include <map>
 #include <memory>
 #include <vector>
 
 namespace llvm {
 
 class raw_ostream;
 class DWARFDataExtractor;
 class MCRegisterInfo;
 struct DIDumpOptions;
 
 namespace dwarf {
 
 constexpr uint32_t InvalidRegisterNumber = UINT32_MAX;
 
 /// A class that represents a location for the Call Frame Address (CFA) or a
 /// register. This is decoded from the DWARF Call Frame Information
 /// instructions and put into an UnwindRow.
 class UnwindLocation {
 public:
   enum Location {
     /// Not specified.
     Unspecified,
     /// Register is not available and can't be recovered.
     Undefined,
     /// Register value is in the register, nothing needs to be done to unwind
     /// it:
     ///   reg = reg
     Same,
     /// Register is in or at the CFA plus an offset:
     ///   reg = CFA + offset
     ///   reg = defef(CFA + offset)
     CFAPlusOffset,
     /// Register or CFA is in or at a register plus offset, optionally in
     /// an address space:
     ///   reg = reg + offset [in addrspace]
     ///   reg = deref(reg + offset [in addrspace])
     RegPlusOffset,
     /// Register or CFA value is in or at a value found by evaluating a DWARF
     /// expression:
     ///   reg = eval(dwarf_expr)
     ///   reg = deref(eval(dwarf_expr))
     DWARFExpr,
     /// Value is a constant value contained in "Offset":
     ///   reg = Offset
     Constant,
   };
 
 private:
   Location Kind;   /// The type of the location that describes how to unwind it.
   uint32_t RegNum; /// The register number for Kind == RegPlusOffset.
   int32_t Offset;  /// The offset for Kind == CFAPlusOffset or RegPlusOffset.
   std::optional<uint32_t> AddrSpace;   /// The address space for Kind ==
                                        /// RegPlusOffset for CFA.
   std::optional<DWARFExpression> Expr; /// The DWARF expression for Kind ==
                                        /// DWARFExpression.
   bool Dereference; /// If true, the resulting location must be dereferenced
                     /// after the location value is computed.
 
   // Constructors are private to force people to use the create static
   // functions.
   UnwindLocation(Location K)
       : Kind(K), RegNum(InvalidRegisterNumber), Offset(0),
         AddrSpace(std::nullopt), Dereference(false) {}
 
   UnwindLocation(Location K, uint32_t Reg, int32_t Off,
                  std::optional<uint32_t> AS, bool Deref)
       : Kind(K), RegNum(Reg), Offset(Off), AddrSpace(AS), Dereference(Deref) {}
 
   UnwindLocation(DWARFExpression E, bool Deref)
       : Kind(DWARFExpr), RegNum(InvalidRegisterNumber), Offset(0), Expr(E),
         Dereference(Deref) {}
 
 public:
   /// Create a location whose rule is set to Unspecified. This means the
   /// register value might be in the same register but it wasn't specified in
   /// the unwind opcodes.
   static UnwindLocation createUnspecified();
   /// Create a location where the value is undefined and not available. This can
   /// happen when a register is volatile and can't be recovered.
   static UnwindLocation createUndefined();
   /// Create a location where the value is known to be in the register itself.
   static UnwindLocation createSame();
   /// Create a location that is in (Deref == false) or at (Deref == true) the
   /// CFA plus an offset. Most registers that are spilled onto the stack use
   /// this rule. The rule for the register will use this rule and specify a
   /// unique offset from the CFA with \a Deref set to true. This value will be
   /// relative to a CFA value which is typically defined using the register
   /// plus offset location. \see createRegisterPlusOffset(...) for more
   /// information.
   static UnwindLocation createIsCFAPlusOffset(int32_t Off);
   static UnwindLocation createAtCFAPlusOffset(int32_t Off);
   /// Create a location where the saved value is in (Deref == false) or at
   /// (Deref == true) a regiser plus an offset and, optionally, in the specified
   /// address space (used mostly for the CFA).
   ///
   /// The CFA is usually defined using this rule by using the stack pointer or
   /// frame pointer as the register, with an offset that accounts for all
   /// spilled registers and all local variables in a function, and Deref ==
   /// false.
   static UnwindLocation
   createIsRegisterPlusOffset(uint32_t Reg, int32_t Off,
                              std::optional<uint32_t> AddrSpace = std::nullopt);
   static UnwindLocation
   createAtRegisterPlusOffset(uint32_t Reg, int32_t Off,
                              std::optional<uint32_t> AddrSpace = std::nullopt);
   /// Create a location whose value is the result of evaluating a DWARF
   /// expression. This allows complex expressions to be evaluated in order to
   /// unwind a register or CFA value.
   static UnwindLocation createIsDWARFExpression(DWARFExpression Expr);
   static UnwindLocation createAtDWARFExpression(DWARFExpression Expr);
   static UnwindLocation createIsConstant(int32_t Value);
 
   Location getLocation() const { return Kind; }
   uint32_t getRegister() const { return RegNum; }
   int32_t getOffset() const { return Offset; }
   uint32_t getAddressSpace() const {
     assert(Kind == RegPlusOffset && AddrSpace);
     return *AddrSpace;
   }
   int32_t getConstant() const { return Offset; }
   /// Some opcodes will modify the CFA location's register only, so we need
   /// to be able to modify the CFA register when evaluating DWARF Call Frame
   /// Information opcodes.
   void setRegister(uint32_t NewRegNum) { RegNum = NewRegNum; }
   /// Some opcodes will modify the CFA location's offset only, so we need
   /// to be able to modify the CFA offset when evaluating DWARF Call Frame
   /// Information opcodes.
   void setOffset(int32_t NewOffset) { Offset = NewOffset; }
   /// Some opcodes modify a constant value and we need to be able to update
   /// the constant value (DW_CFA_GNU_window_save which is also known as
   // DW_CFA_AARCH64_negate_ra_state).
   void setConstant(int32_t Value) { Offset = Value; }
 
   std::optional<DWARFExpression> getDWARFExpressionBytes() const {
     return Expr;
   }
   /// Dump a location expression as text and use the register information if
   /// some is provided.
   ///
   /// \param OS the stream to use for output.
   ///
   /// \param MRI register information that helps emit register names insteead
   /// of raw register numbers.
   ///
   /// \param IsEH true if the DWARF Call Frame Information is from .eh_frame
   /// instead of from .debug_frame. This is needed for register number
   /// conversion because some register numbers differ between the two sections
   /// for certain architectures like x86.
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts) const;
 
   bool operator==(const UnwindLocation &RHS) const;
 };
 
 raw_ostream &operator<<(raw_ostream &OS, const UnwindLocation &R);
 
 /// A class that can track all registers with locations in a UnwindRow object.
 ///
 /// Register locations use a map where the key is the register number and the
 /// the value is a UnwindLocation.
 ///
 /// The register maps are put into a class so that all register locations can
 /// be copied when parsing the unwind opcodes DW_CFA_remember_state and
 /// DW_CFA_restore_state.
 class RegisterLocations {
   std::map<uint32_t, UnwindLocation> Locations;
 
 public:
   /// Return the location for the register in \a RegNum if there is a location.
   ///
   /// \param RegNum the register number to find a location for.
   ///
   /// \returns A location if one is available for \a RegNum, or std::nullopt
   /// otherwise.
   std::optional<UnwindLocation> getRegisterLocation(uint32_t RegNum) const {
     auto Pos = Locations.find(RegNum);
     if (Pos == Locations.end())
       return std::nullopt;
     return Pos->second;
   }
 
   /// Set the location for the register in \a RegNum to \a Location.
   ///
   /// \param RegNum the register number to set the location for.
   ///
   /// \param Location the UnwindLocation that describes how to unwind the value.
   void setRegisterLocation(uint32_t RegNum, const UnwindLocation &Location) {
     Locations.erase(RegNum);
     Locations.insert(std::make_pair(RegNum, Location));
   }
 
   /// Removes any rule for the register in \a RegNum.
   ///
   /// \param RegNum the register number to remove the location for.
   void removeRegisterLocation(uint32_t RegNum) { Locations.erase(RegNum); }
 
   /// Dump all registers + locations that are currently defined in this object.
   ///
   /// \param OS the stream to use for output.
   ///
   /// \param MRI register information that helps emit register names insteead
   /// of raw register numbers.
   ///
   /// \param IsEH true if the DWARF Call Frame Information is from .eh_frame
   /// instead of from .debug_frame. This is needed for register number
   /// conversion because some register numbers differ between the two sections
   /// for certain architectures like x86.
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts) const;
 
   /// Returns true if we have any register locations in this object.
   bool hasLocations() const { return !Locations.empty(); }
 
   size_t size() const { return Locations.size(); }
 
   bool operator==(const RegisterLocations &RHS) const {
     return Locations == RHS.Locations;
   }
 };
 
 raw_ostream &operator<<(raw_ostream &OS, const RegisterLocations &RL);
 
 /// A class that represents a single row in the unwind table that is decoded by
 /// parsing the DWARF Call Frame Information opcodes.
 ///
 /// The row consists of an optional address, the rule to unwind the CFA and all
 /// rules to unwind any registers. If the address doesn't have a value, this
 /// row represents the initial instructions for a CIE. If the address has a
 /// value the UnwindRow represents a row in the UnwindTable for a FDE. The
 /// address is the first address for which the CFA location and register rules
 /// are valid within a function.
 ///
 /// UnwindRow objects are created by parsing opcodes in the DWARF Call Frame
 /// Information and UnwindRow objects are lazily populated and pushed onto a
 /// stack in the UnwindTable when evaluating this state machine. Accessors are
 /// needed for the address, CFA value, and register locations as the opcodes
 /// encode a state machine that produces a sorted array of UnwindRow objects
 /// \see UnwindTable.
 class UnwindRow {
   /// The address will be valid when parsing the instructions in a FDE. If
   /// invalid, this object represents the initial instructions of a CIE.
   std::optional<uint64_t> Address; ///< Address for row in FDE, invalid for CIE.
   UnwindLocation CFAValue;    ///< How to unwind the Call Frame Address (CFA).
   RegisterLocations RegLocs;  ///< How to unwind all registers in this list.
 
 public:
   UnwindRow() : CFAValue(UnwindLocation::createUnspecified()) {}
 
   /// Returns true if the address is valid in this object.
   bool hasAddress() const { return Address.has_value(); }
 
   /// Get the address for this row.
   ///
   /// Clients should only call this function after verifying it has a valid
   /// address with a call to \see hasAddress().
   uint64_t getAddress() const { return *Address; }
 
   /// Set the address for this UnwindRow.
   ///
   /// The address represents the first address for which the CFAValue and
   /// RegLocs are valid within a function.
   void setAddress(uint64_t Addr) { Address = Addr; }
 
   /// Offset the address for this UnwindRow.
   ///
   /// The address represents the first address for which the CFAValue and
   /// RegLocs are valid within a function. Clients must ensure that this object
   /// already has an address (\see hasAddress()) prior to calling this
   /// function.
   void slideAddress(uint64_t Offset) { *Address += Offset; }
   UnwindLocation &getCFAValue() { return CFAValue; }
   const UnwindLocation &getCFAValue() const { return CFAValue; }
   RegisterLocations &getRegisterLocations() { return RegLocs; }
   const RegisterLocations &getRegisterLocations() const { return RegLocs; }
 
   /// Dump the UnwindRow to the stream.
   ///
   /// \param OS the stream to use for output.
   ///
   /// \param MRI register information that helps emit register names insteead
   /// of raw register numbers.
   ///
   /// \param IsEH true if the DWARF Call Frame Information is from .eh_frame
   /// instead of from .debug_frame. This is needed for register number
   /// conversion because some register numbers differ between the two sections
   /// for certain architectures like x86.
   ///
   /// \param IndentLevel specify the indent level as an integer. The UnwindRow
   /// will be output to the stream preceded by 2 * IndentLevel number of spaces.
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts,
             unsigned IndentLevel = 0) const;
 };
 
 raw_ostream &operator<<(raw_ostream &OS, const UnwindRow &Row);
 
 class CFIProgram;
 class CIE;
 class FDE;
 
 /// A class that contains all UnwindRow objects for an FDE or a single unwind
 /// row for a CIE. To unwind an address the rows, which are sorted by start
 /// address, can be searched to find the UnwindRow with the lowest starting
 /// address that is greater than or equal to the address that is being looked
 /// up.
 class UnwindTable {
 public:
   using RowContainer = std::vector<UnwindRow>;
   using iterator = RowContainer::iterator;
   using const_iterator = RowContainer::const_iterator;
 
   size_t size() const { return Rows.size(); }
   iterator begin() { return Rows.begin(); }
   const_iterator begin() const { return Rows.begin(); }
   iterator end() { return Rows.end(); }
   const_iterator end() const { return Rows.end(); }
   const UnwindRow &operator[](size_t Index) const {
     assert(Index < size());
     return Rows[Index];
   }
 
   /// Dump the UnwindTable to the stream.
   ///
   /// \param OS the stream to use for output.
   ///
   /// \param MRI register information that helps emit register names insteead
   /// of raw register numbers.
   ///
   /// \param IsEH true if the DWARF Call Frame Information is from .eh_frame
   /// instead of from .debug_frame. This is needed for register number
   /// conversion because some register numbers differ between the two sections
   /// for certain architectures like x86.
   ///
   /// \param IndentLevel specify the indent level as an integer. The UnwindRow
   /// will be output to the stream preceded by 2 * IndentLevel number of spaces.
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts,
             unsigned IndentLevel = 0) const;
 
   /// Create an UnwindTable from a Common Information Entry (CIE).
   ///
   /// \param Cie The Common Information Entry to extract the table from. The
   /// CFIProgram is retrieved from the \a Cie object and used to create the
   /// UnwindTable.
   ///
   /// \returns An error if the DWARF Call Frame Information opcodes have state
   /// machine errors, or a valid UnwindTable otherwise.
   static Expected<UnwindTable> create(const CIE *Cie);
 
   /// Create an UnwindTable from a Frame Descriptor Entry (FDE).
   ///
   /// \param Fde The Frame Descriptor Entry to extract the table from. The
   /// CFIProgram is retrieved from the \a Fde object and used to create the
   /// UnwindTable.
   ///
   /// \returns An error if the DWARF Call Frame Information opcodes have state
   /// machine errors, or a valid UnwindTable otherwise.
   static Expected<UnwindTable> create(const FDE *Fde);
 
 private:
   RowContainer Rows;
   /// The end address when data is extracted from a FDE. This value will be
   /// invalid when a UnwindTable is extracted from a CIE.
   std::optional<uint64_t> EndAddress;
 
   /// Parse the information in the CFIProgram and update the CurrRow object
   /// that the state machine describes.
   ///
   /// This is an internal implementation that emulates the state machine
   /// described in the DWARF Call Frame Information opcodes and will push
   /// CurrRow onto the Rows container when needed.
   ///
   /// \param CFIP the CFI program that contains the opcodes from a CIE or FDE.
   ///
   /// \param CurrRow the current row to modify while parsing the state machine.
   ///
   /// \param InitialLocs If non-NULL, we are parsing a FDE and this contains
   /// the initial register locations from the CIE. If NULL, then a CIE's
   /// opcodes are being parsed and this is not needed. This is used for the
   /// DW_CFA_restore and DW_CFA_restore_extended opcodes.
   Error parseRows(const CFIProgram &CFIP, UnwindRow &CurrRow,
                   const RegisterLocations *InitialLocs);
 };
 
 raw_ostream &operator<<(raw_ostream &OS, const UnwindTable &Rows);
 
 /// Represent a sequence of Call Frame Information instructions that, when read
 /// in order, construct a table mapping PC to frame state. This can also be
 /// referred to as "CFI rules" in DWARF literature to avoid confusion with
 /// computer programs in the broader sense, and in this context each instruction
 /// would be a rule to establish the mapping. Refer to pg. 172 in the DWARF5
 /// manual, "6.4.1 Structure of Call Frame Information".
 class CFIProgram {
 public:
   static constexpr size_t MaxOperands = 3;
   typedef SmallVector<uint64_t, MaxOperands> Operands;
 
   /// An instruction consists of a DWARF CFI opcode and an optional sequence of
   /// operands. If it refers to an expression, then this expression has its own
   /// sequence of operations and operands handled separately by DWARFExpression.
   struct Instruction {
     Instruction(uint8_t Opcode) : Opcode(Opcode) {}
 
     uint8_t Opcode;
     Operands Ops;
     // Associated DWARF expression in case this instruction refers to one
     std::optional<DWARFExpression> Expression;
 
     Expected<uint64_t> getOperandAsUnsigned(const CFIProgram &CFIP,
                                             uint32_t OperandIdx) const;
 
     Expected<int64_t> getOperandAsSigned(const CFIProgram &CFIP,
                                          uint32_t OperandIdx) const;
   };
 
   using InstrList = std::vector<Instruction>;
   using iterator = InstrList::iterator;
   using const_iterator = InstrList::const_iterator;
 
   iterator begin() { return Instructions.begin(); }
   const_iterator begin() const { return Instructions.begin(); }
   iterator end() { return Instructions.end(); }
   const_iterator end() const { return Instructions.end(); }
 
   unsigned size() const { return (unsigned)Instructions.size(); }
   bool empty() const { return Instructions.empty(); }
   uint64_t codeAlign() const { return CodeAlignmentFactor; }
   int64_t dataAlign() const { return DataAlignmentFactor; }
   Triple::ArchType triple() const { return Arch; }
 
   CFIProgram(uint64_t CodeAlignmentFactor, int64_t DataAlignmentFactor,
              Triple::ArchType Arch)
       : CodeAlignmentFactor(CodeAlignmentFactor),
         DataAlignmentFactor(DataAlignmentFactor),
         Arch(Arch) {}
 
   /// Parse and store a sequence of CFI instructions from Data,
   /// starting at *Offset and ending at EndOffset. *Offset is updated
   /// to EndOffset upon successful parsing, or indicates the offset
   /// where a problem occurred in case an error is returned.
   Error parse(DWARFDataExtractor Data, uint64_t *Offset, uint64_t EndOffset);
 
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts, unsigned IndentLevel,
             std::optional<uint64_t> InitialLocation) const;
 
   void addInstruction(const Instruction &I) { Instructions.push_back(I); }
 
   /// Get a DWARF CFI call frame string for the given DW_CFA opcode.
   StringRef callFrameString(unsigned Opcode) const;
 
 private:
   std::vector<Instruction> Instructions;
   const uint64_t CodeAlignmentFactor;
   const int64_t DataAlignmentFactor;
   Triple::ArchType Arch;
 
   /// Convenience method to add a new instruction with the given opcode.
   void addInstruction(uint8_t Opcode) {
     Instructions.push_back(Instruction(Opcode));
   }
 
   /// Add a new single-operand instruction.
   void addInstruction(uint8_t Opcode, uint64_t Operand1) {
     Instructions.push_back(Instruction(Opcode));
     Instructions.back().Ops.push_back(Operand1);
   }
 
   /// Add a new instruction that has two operands.
   void addInstruction(uint8_t Opcode, uint64_t Operand1, uint64_t Operand2) {
     Instructions.push_back(Instruction(Opcode));
     Instructions.back().Ops.push_back(Operand1);
     Instructions.back().Ops.push_back(Operand2);
   }
 
   /// Add a new instruction that has three operands.
   void addInstruction(uint8_t Opcode, uint64_t Operand1, uint64_t Operand2,
                       uint64_t Operand3) {
     Instructions.push_back(Instruction(Opcode));
     Instructions.back().Ops.push_back(Operand1);
     Instructions.back().Ops.push_back(Operand2);
     Instructions.back().Ops.push_back(Operand3);
   }
 
   /// Types of operands to CFI instructions
   /// In DWARF, this type is implicitly tied to a CFI instruction opcode and
   /// thus this type doesn't need to be explicitly written to the file (this is
   /// not a DWARF encoding). The relationship of instrs to operand types can
   /// be obtained from getOperandTypes() and is only used to simplify
   /// instruction printing.
   enum OperandType {
     OT_Unset,
     OT_None,
     OT_Address,
     OT_Offset,
     OT_FactoredCodeOffset,
     OT_SignedFactDataOffset,
     OT_UnsignedFactDataOffset,
     OT_Register,
     OT_AddressSpace,
     OT_Expression
   };
 
   /// Get the OperandType as a "const char *".
   static const char *operandTypeString(OperandType OT);
 
   /// Retrieve the array describing the types of operands according to the enum
   /// above. This is indexed by opcode.
   static ArrayRef<OperandType[MaxOperands]> getOperandTypes();
 
   /// Print \p Opcode's operand number \p OperandIdx which has value \p Operand.
   void printOperand(raw_ostream &OS, DIDumpOptions DumpOpts,
                     const Instruction &Instr, unsigned OperandIdx,
                     uint64_t Operand, std::optional<uint64_t> &Address) const;
 };
 
 /// An entry in either debug_frame or eh_frame. This entry can be a CIE or an
 /// FDE.
 class FrameEntry {
 public:
   enum FrameKind { FK_CIE, FK_FDE };
 
   FrameEntry(FrameKind K, bool IsDWARF64, uint64_t Offset, uint64_t Length,
              uint64_t CodeAlign, int64_t DataAlign, Triple::ArchType Arch)
       : Kind(K), IsDWARF64(IsDWARF64), Offset(Offset), Length(Length),
         CFIs(CodeAlign, DataAlign, Arch) {}
 
   virtual ~FrameEntry() = default;
 
   FrameKind getKind() const { return Kind; }
   uint64_t getOffset() const { return Offset; }
   uint64_t getLength() const { return Length; }
   const CFIProgram &cfis() const { return CFIs; }
   CFIProgram &cfis() { return CFIs; }
 
   /// Dump the instructions in this CFI fragment
   virtual void dump(raw_ostream &OS, DIDumpOptions DumpOpts) const = 0;
 
 protected:
   const FrameKind Kind;
 
   const bool IsDWARF64;
 
   /// Offset of this entry in the section.
   const uint64_t Offset;
 
   /// Entry length as specified in DWARF.
   const uint64_t Length;
 
   CFIProgram CFIs;
 };
 
 /// DWARF Common Information Entry (CIE)
 class CIE : public FrameEntry {
 public:
   // CIEs (and FDEs) are simply container classes, so the only sensible way to
   // create them is by providing the full parsed contents in the constructor.
   CIE(bool IsDWARF64, uint64_t Offset, uint64_t Length, uint8_t Version,
       SmallString<8> Augmentation, uint8_t AddressSize,
       uint8_t SegmentDescriptorSize, uint64_t CodeAlignmentFactor,
       int64_t DataAlignmentFactor, uint64_t ReturnAddressRegister,
       SmallString<8> AugmentationData, uint32_t FDEPointerEncoding,
       uint32_t LSDAPointerEncoding, std::optional<uint64_t> Personality,
       std::optional<uint32_t> PersonalityEnc, Triple::ArchType Arch)
       : FrameEntry(FK_CIE, IsDWARF64, Offset, Length, CodeAlignmentFactor,
                    DataAlignmentFactor, Arch),
         Version(Version), Augmentation(std::move(Augmentation)),
         AddressSize(AddressSize), SegmentDescriptorSize(SegmentDescriptorSize),
         CodeAlignmentFactor(CodeAlignmentFactor),
         DataAlignmentFactor(DataAlignmentFactor),
         ReturnAddressRegister(ReturnAddressRegister),
         AugmentationData(std::move(AugmentationData)),
         FDEPointerEncoding(FDEPointerEncoding),
         LSDAPointerEncoding(LSDAPointerEncoding), Personality(Personality),
         PersonalityEnc(PersonalityEnc) {}
 
   static bool classof(const FrameEntry *FE) { return FE->getKind() == FK_CIE; }
 
   StringRef getAugmentationString() const { return Augmentation; }
   uint64_t getCodeAlignmentFactor() const { return CodeAlignmentFactor; }
   int64_t getDataAlignmentFactor() const { return DataAlignmentFactor; }
   uint8_t getVersion() const { return Version; }
   uint64_t getReturnAddressRegister() const { return ReturnAddressRegister; }
   std::optional<uint64_t> getPersonalityAddress() const { return Personality; }
   std::optional<uint32_t> getPersonalityEncoding() const {
     return PersonalityEnc;
   }
 
   StringRef getAugmentationData() const { return AugmentationData; }
 
   uint32_t getFDEPointerEncoding() const { return FDEPointerEncoding; }
 
   uint32_t getLSDAPointerEncoding() const { return LSDAPointerEncoding; }
 
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts) const override;
 
 private:
   /// The following fields are defined in section 6.4.1 of the DWARF standard v4
   const uint8_t Version;
   const SmallString<8> Augmentation;
   const uint8_t AddressSize;
   const uint8_t SegmentDescriptorSize;
   const uint64_t CodeAlignmentFactor;
   const int64_t DataAlignmentFactor;
   const uint64_t ReturnAddressRegister;
 
   // The following are used when the CIE represents an EH frame entry.
   const SmallString<8> AugmentationData;
   const uint32_t FDEPointerEncoding;
   const uint32_t LSDAPointerEncoding;
   const std::optional<uint64_t> Personality;
   const std::optional<uint32_t> PersonalityEnc;
 };
 
 /// DWARF Frame Description Entry (FDE)
 class FDE : public FrameEntry {
 public:
   FDE(bool IsDWARF64, uint64_t Offset, uint64_t Length, uint64_t CIEPointer,
       uint64_t InitialLocation, uint64_t AddressRange, CIE *Cie,
       std::optional<uint64_t> LSDAAddress, Triple::ArchType Arch)
       : FrameEntry(FK_FDE, IsDWARF64, Offset, Length,
                    Cie ? Cie->getCodeAlignmentFactor() : 0,
                    Cie ? Cie->getDataAlignmentFactor() : 0, Arch),
         CIEPointer(CIEPointer), InitialLocation(InitialLocation),
         AddressRange(AddressRange), LinkedCIE(Cie), LSDAAddress(LSDAAddress) {}
 
   ~FDE() override = default;
 
   const CIE *getLinkedCIE() const { return LinkedCIE; }
   uint64_t getCIEPointer() const { return CIEPointer; }
   uint64_t getInitialLocation() const { return InitialLocation; }
   uint64_t getAddressRange() const { return AddressRange; }
   std::optional<uint64_t> getLSDAAddress() const { return LSDAAddress; }
 
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts) const override;
 
   static bool classof(const FrameEntry *FE) { return FE->getKind() == FK_FDE; }
 
 private:
   /// The following fields are defined in section 6.4.1 of the DWARFv3 standard.
   /// Note that CIE pointers in EH FDEs, unlike DWARF FDEs, contain relative
   /// offsets to the linked CIEs. See the following link for more info:
   /// https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
   const uint64_t CIEPointer;
   const uint64_t InitialLocation;
   const uint64_t AddressRange;
   const CIE *LinkedCIE;
   const std::optional<uint64_t> LSDAAddress;
 };
 
 } // end namespace dwarf
 
 /// A parsed .debug_frame or .eh_frame section
 class DWARFDebugFrame {
   const Triple::ArchType Arch;
   // True if this is parsing an eh_frame section.
   const bool IsEH;
   // Not zero for sane pointer values coming out of eh_frame
   const uint64_t EHFrameAddress;
 
   std::vector<std::unique_ptr<dwarf::FrameEntry>> Entries;
   using iterator = pointee_iterator<decltype(Entries)::const_iterator>;
 
   /// Return the entry at the given offset or nullptr.
   dwarf::FrameEntry *getEntryAtOffset(uint64_t Offset) const;
 
 public:
   // If IsEH is true, assume it is a .eh_frame section. Otherwise,
   // it is a .debug_frame section. EHFrameAddress should be different
   // than zero for correct parsing of .eh_frame addresses when they
   // use a PC-relative encoding.
   DWARFDebugFrame(Triple::ArchType Arch,
                   bool IsEH = false, uint64_t EHFrameAddress = 0);
   ~DWARFDebugFrame();
 
   /// Dump the section data into the given stream.
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts,
             std::optional<uint64_t> Offset) const;
 
   /// Parse the section from raw data. \p Data is assumed to contain the whole
   /// frame section contents to be parsed.
   Error parse(DWARFDataExtractor Data);
 
   /// Return whether the section has any entries.
   bool empty() const { return Entries.empty(); }
 
   /// DWARF Frame entries accessors
   iterator begin() const { return Entries.begin(); }
   iterator end() const { return Entries.end(); }
   iterator_range<iterator> entries() const {
     return iterator_range<iterator>(Entries.begin(), Entries.end());
   }
 
   uint64_t getEHFrameAddress() const { return EHFrameAddress; }
 };
 
 } // end namespace llvm
 
 #endif // LLVM_DEBUGINFO_DWARF_DWARFDEBUGFRAME_H

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