text: //===- DWARFContext.h -------------------------------------------*- C++ -*-===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===/
  
  #ifndef LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H
  #define LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H
  
  #include "llvm/ADT/MapVector.h"
  #include "llvm/ADT/SmallString.h"
  #include "llvm/ADT/SmallVector.h"
  #include "llvm/ADT/StringMap.h"
  #include "llvm/ADT/StringRef.h"
  #include "llvm/ADT/iterator_range.h"
  #include "llvm/DebugInfo/DIContext.h"
  #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
  #include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
  #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
  #include "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
  #include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
  #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
  #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
  #include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
  #include "llvm/DebugInfo/DWARF/DWARFDie.h"
  #include "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
  #include "llvm/DebugInfo/DWARF/DWARFObject.h"
  #include "llvm/DebugInfo/DWARF/DWARFSection.h"
  #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
  #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
  #include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
  #include "llvm/Object/Binary.h"
  #include "llvm/Object/ObjectFile.h"
  #include "llvm/Support/DataExtractor.h"
  #include "llvm/Support/Error.h"
  #include "llvm/Support/Host.h"
  #include <cstdint>
  #include <deque>
  #include <map>
  #include <memory>
  
  namespace llvm {
  
  class MCRegisterInfo;
  class MemoryBuffer;
  class raw_ostream;
  
  /// DWARFContext
  /// This data structure is the top level entity that deals with dwarf debug
  /// information parsing. The actual data is supplied through DWARFObj.
  class DWARFContext : public DIContext {
    DWARFUnitVector NormalUnits;
    std::unique_ptr<DWARFUnitIndex> CUIndex;
    std::unique_ptr<DWARFGdbIndex> GdbIndex;
    std::unique_ptr<DWARFUnitIndex> TUIndex;
    std::unique_ptr<DWARFDebugAbbrev> Abbrev;
    std::unique_ptr<DWARFDebugLoc> Loc;
    std::unique_ptr<DWARFDebugAranges> Aranges;
    std::unique_ptr<DWARFDebugLine> Line;
    std::unique_ptr<DWARFDebugFrame> DebugFrame;
    std::unique_ptr<DWARFDebugFrame> EHFrame;
    std::unique_ptr<DWARFDebugMacro> Macro;
    std::unique_ptr<DWARFDebugMacro> Macinfo;
    std::unique_ptr<DWARFDebugNames> Names;
    std::unique_ptr<AppleAcceleratorTable> AppleNames;
    std::unique_ptr<AppleAcceleratorTable> AppleTypes;
    std::unique_ptr<AppleAcceleratorTable> AppleNamespaces;
    std::unique_ptr<AppleAcceleratorTable> AppleObjC;
  
    DWARFUnitVector DWOUnits;
    std::unique_ptr<DWARFDebugAbbrev> AbbrevDWO;
    std::unique_ptr<DWARFDebugMacro> MacinfoDWO;
    std::unique_ptr<DWARFDebugMacro> MacroDWO;
  
    /// The maximum DWARF version of all units.
    unsigned MaxVersion = 0;
  
    struct DWOFile {
      object::OwningBinary<object::ObjectFile> File;
      std::unique_ptr<DWARFContext> Context;
    };
    StringMap<std::weak_ptr<DWOFile>> DWOFiles;
    std::weak_ptr<DWOFile> DWP;
    bool CheckedForDWP = false;
    std::string DWPName;
  
    std::unique_ptr<MCRegisterInfo> RegInfo;
  
    std::function<void(Error)> RecoverableErrorHandler =
        WithColor::defaultErrorHandler;
    std::function<void(Error)> WarningHandler = WithColor::defaultWarningHandler;
  
    /// Read compile units from the debug_info section (if necessary)
    /// and type units from the debug_types sections (if necessary)
    /// and store them in NormalUnits.
    void parseNormalUnits();
  
    /// Read compile units from the debug_info.dwo section (if necessary)
    /// and type units from the debug_types.dwo section (if necessary)
    /// and store them in DWOUnits.
    /// If \p Lazy is true, set up to parse but don't actually parse them.
    enum { EagerParse = false, LazyParse = true };
    void parseDWOUnits(bool Lazy = false);
  
    std::unique_ptr<const DWARFObject> DObj;
  
    /// Helper enum to distinguish between macro[.dwo] and macinfo[.dwo]
    /// section.
    enum MacroSecType {
      MacinfoSection,
      MacinfoDwoSection,
      MacroSection,
      MacroDwoSection
    };
  
  public:
    DWARFContext(std::unique_ptr<const DWARFObject> DObj,
                 std::string DWPName = "",
                 std::function<void(Error)> RecoverableErrorHandler =
                     WithColor::defaultErrorHandler,
                 std::function<void(Error)> WarningHandler =
                     WithColor::defaultWarningHandler);
    ~DWARFContext();
  
    DWARFContext(DWARFContext &) = delete;
    DWARFContext &operator=(DWARFContext &) = delete;
  
    const DWARFObject &getDWARFObj() const { return *DObj; }
  
    static bool classof(const DIContext *DICtx) {
      return DICtx->getKind() == CK_DWARF;
    }
  
    /// Dump a textual representation to \p OS. If any \p DumpOffsets are present,
    /// dump only the record at the specified offset.
    void dump(raw_ostream &OS, DIDumpOptions DumpOpts,
              std::array<Optional<uint64_t>, DIDT_ID_Count> DumpOffsets);
  
    void dump(raw_ostream &OS, DIDumpOptions DumpOpts) override {
      std::array<Optional<uint64_t>, DIDT_ID_Count> DumpOffsets;
      dump(OS, DumpOpts, DumpOffsets);
    }
  
    bool verify(raw_ostream &OS, DIDumpOptions DumpOpts = {}) override;
  
    using unit_iterator_range = DWARFUnitVector::iterator_range;
    using compile_unit_range = DWARFUnitVector::compile_unit_range;
  
    /// Get units from .debug_info in this context.
    unit_iterator_range info_section_units() {
      parseNormalUnits();
      return unit_iterator_range(NormalUnits.begin(),
                                 NormalUnits.begin() +
                                     NormalUnits.getNumInfoUnits());
    }
  
    /// Get units from .debug_types in this context.
    unit_iterator_range types_section_units() {
      parseNormalUnits();
      return unit_iterator_range(
          NormalUnits.begin() + NormalUnits.getNumInfoUnits(), NormalUnits.end());
    }
  
    /// Get compile units in this context.
    compile_unit_range compile_units() {
      return make_filter_range(info_section_units(), isCompileUnit);
    }
  
    // If you want type_units(), it'll need to be a concat iterator of a filter of
    // TUs in info_section + all the (all type) units in types_section
  
    /// Get all normal compile/type units in this context.
    unit_iterator_range normal_units() {
      parseNormalUnits();
      return unit_iterator_range(NormalUnits.begin(), NormalUnits.end());
    }
  
    /// Get units from .debug_info..dwo in the DWO context.
    unit_iterator_range dwo_info_section_units() {
      parseDWOUnits();
      return unit_iterator_range(DWOUnits.begin(),
                                 DWOUnits.begin() + DWOUnits.getNumInfoUnits());
    }
  
    /// Get units from .debug_types.dwo in the DWO context.
    unit_iterator_range dwo_types_section_units() {
      parseDWOUnits();
      return unit_iterator_range(DWOUnits.begin() + DWOUnits.getNumInfoUnits(),
                                 DWOUnits.end());
    }
  
    /// Get compile units in the DWO context.
    compile_unit_range dwo_compile_units() {
      return make_filter_range(dwo_info_section_units(), isCompileUnit);
    }
  
    // If you want dwo_type_units(), it'll need to be a concat iterator of a
    // filter of TUs in dwo_info_section + all the (all type) units in
    // dwo_types_section.
  
    /// Get all units in the DWO context.
    unit_iterator_range dwo_units() {
      parseDWOUnits();
      return unit_iterator_range(DWOUnits.begin(), DWOUnits.end());
    }
  
    /// Get the number of compile units in this context.
    unsigned getNumCompileUnits() {
      parseNormalUnits();
      return NormalUnits.getNumInfoUnits();
    }
  
    /// Get the number of type units in this context.
    unsigned getNumTypeUnits() {
      parseNormalUnits();
      return NormalUnits.getNumTypesUnits();
    }
  
    /// Get the number of compile units in the DWO context.
    unsigned getNumDWOCompileUnits() {
      parseDWOUnits();
      return DWOUnits.getNumInfoUnits();
    }
  
    /// Get the number of type units in the DWO context.
    unsigned getNumDWOTypeUnits() {
      parseDWOUnits();
      return DWOUnits.getNumTypesUnits();
    }
  
    /// Get the unit at the specified index.
    DWARFUnit *getUnitAtIndex(unsigned index) {
      parseNormalUnits();
      return NormalUnits[index].get();
    }
  
    /// Get the unit at the specified index for the DWO units.
    DWARFUnit *getDWOUnitAtIndex(unsigned index) {
      parseDWOUnits();
      return DWOUnits[index].get();
    }
  
    DWARFCompileUnit *getDWOCompileUnitForHash(uint64_t Hash);
  
    /// Return the compile unit that includes an offset (relative to .debug_info).
    DWARFCompileUnit *getCompileUnitForOffset(uint64_t Offset);
  
    /// Get a DIE given an exact offset.
    DWARFDie getDIEForOffset(uint64_t Offset);
  
    unsigned getMaxVersion() {
      // Ensure info units have been parsed to discover MaxVersion
      info_section_units();
      return MaxVersion;
    }
  
    unsigned getMaxDWOVersion() {
      // Ensure DWO info units have been parsed to discover MaxVersion
      dwo_info_section_units();
      return MaxVersion;
    }
  
    void setMaxVersionIfGreater(unsigned Version) {
      if (Version > MaxVersion)
        MaxVersion = Version;
    }
  
    const DWARFUnitIndex &getCUIndex();
    DWARFGdbIndex &getGdbIndex();
    const DWARFUnitIndex &getTUIndex();
  
    /// Get a pointer to the parsed DebugAbbrev object.
    const DWARFDebugAbbrev *getDebugAbbrev();
  
    /// Get a pointer to the parsed DebugLoc object.
    const DWARFDebugLoc *getDebugLoc();
  
    /// Get a pointer to the parsed dwo abbreviations object.
    const DWARFDebugAbbrev *getDebugAbbrevDWO();
  
    /// Get a pointer to the parsed DebugAranges object.
    const DWARFDebugAranges *getDebugAranges();
  
    /// Get a pointer to the parsed frame information object.
    Expected<const DWARFDebugFrame *> getDebugFrame();
  
    /// Get a pointer to the parsed eh frame information object.
    Expected<const DWARFDebugFrame *> getEHFrame();
  
    /// Get a pointer to the parsed DebugMacinfo information object.
    const DWARFDebugMacro *getDebugMacinfo();
  
    /// Get a pointer to the parsed DebugMacinfoDWO information object.
    const DWARFDebugMacro *getDebugMacinfoDWO();
  
    /// Get a pointer to the parsed DebugMacro information object.
    const DWARFDebugMacro *getDebugMacro();
  
    /// Get a pointer to the parsed DebugMacroDWO information object.
    const DWARFDebugMacro *getDebugMacroDWO();
  
    /// Get a reference to the parsed accelerator table object.
    const DWARFDebugNames &getDebugNames();
  
    /// Get a reference to the parsed accelerator table object.
    const AppleAcceleratorTable &getAppleNames();
  
    /// Get a reference to the parsed accelerator table object.
    const AppleAcceleratorTable &getAppleTypes();
  
    /// Get a reference to the parsed accelerator table object.
    const AppleAcceleratorTable &getAppleNamespaces();
  
    /// Get a reference to the parsed accelerator table object.
    const AppleAcceleratorTable &getAppleObjC();
  
    /// Get a pointer to a parsed line table corresponding to a compile unit.
    /// Report any parsing issues as warnings on stderr.
    const DWARFDebugLine::LineTable *getLineTableForUnit(DWARFUnit *U);
  
    /// Get a pointer to a parsed line table corresponding to a compile unit.
    /// Report any recoverable parsing problems using the handler.
    Expected<const DWARFDebugLine::LineTable *>
    getLineTableForUnit(DWARFUnit *U,
                        function_ref<void(Error)> RecoverableErrorHandler);
  
    DataExtractor getStringExtractor() const {
      return DataExtractor(DObj->getStrSection(), false, 0);
    }
    DataExtractor getStringDWOExtractor() const {
      return DataExtractor(DObj->getStrDWOSection(), false, 0);
    }
    DataExtractor getLineStringExtractor() const {
      return DataExtractor(DObj->getLineStrSection(), false, 0);
    }
  
    /// Wraps the returned DIEs for a given address.
    struct DIEsForAddress {
      DWARFCompileUnit *CompileUnit = nullptr;
      DWARFDie FunctionDIE;
      DWARFDie BlockDIE;
      explicit operator bool() const { return CompileUnit != nullptr; }
    };
  
    /// Get the compilation unit, the function DIE and lexical block DIE for the
    /// given address where applicable.
    /// TODO: change input parameter from "uint64_t Address"
    ///       into "SectionedAddress Address"
    DIEsForAddress getDIEsForAddress(uint64_t Address);
  
    DILineInfo getLineInfoForAddress(
        object::SectionedAddress Address,
        DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;
    DILineInfoTable getLineInfoForAddressRange(
        object::SectionedAddress Address, uint64_t Size,
        DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;
    DIInliningInfo getInliningInfoForAddress(
        object::SectionedAddress Address,
        DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;
  
    std::vector<DILocal>
    getLocalsForAddress(object::SectionedAddress Address) override;
  
    bool isLittleEndian() const { return DObj->isLittleEndian(); }
    static unsigned getMaxSupportedVersion() { return 5; }
    static bool isSupportedVersion(unsigned version) {
      return version >= 2 && version <= getMaxSupportedVersion();
    }
  
    static SmallVector<uint8_t, 3> getSupportedAddressSizes() {
      return {2, 4, 8};
    }
    static bool isAddressSizeSupported(unsigned AddressSize) {
      return llvm::is_contained(getSupportedAddressSizes(), AddressSize);
    }
    template <typename... Ts>
    static Error checkAddressSizeSupported(unsigned AddressSize,
                                           std::error_code EC, char const *Fmt,
                                           const Ts &...Vals) {
      if (isAddressSizeSupported(AddressSize))
        return Error::success();
      std::string Buffer;
      raw_string_ostream Stream(Buffer);
      Stream << format(Fmt, Vals...)
             << " has unsupported address size: " << AddressSize
             << " (supported are ";
      ListSeparator LS;
      for (unsigned Size : DWARFContext::getSupportedAddressSizes())
        Stream << LS << Size;
      Stream << ')';
      return make_error<StringError>(Stream.str(), EC);
    }
  
    std::shared_ptr<DWARFContext> getDWOContext(StringRef AbsolutePath);
  
    const MCRegisterInfo *getRegisterInfo() const { return RegInfo.get(); }
  
    function_ref<void(Error)> getRecoverableErrorHandler() {
      return RecoverableErrorHandler;
    }
  
    function_ref<void(Error)> getWarningHandler() { return WarningHandler; }
  
    enum class ProcessDebugRelocations { Process, Ignore };
  
    static std::unique_ptr<DWARFContext>
    create(const object::ObjectFile &Obj,
           ProcessDebugRelocations RelocAction = ProcessDebugRelocations::Process,
           const LoadedObjectInfo *L = nullptr, std::string DWPName = "",
           std::function<void(Error)> RecoverableErrorHandler =
               WithColor::defaultErrorHandler,
           std::function<void(Error)> WarningHandler =
               WithColor::defaultWarningHandler);
  
    static std::unique_ptr<DWARFContext>
    create(const StringMap<std::unique_ptr<MemoryBuffer>> &Sections,
           uint8_t AddrSize, bool isLittleEndian = sys::IsLittleEndianHost,
           std::function<void(Error)> RecoverableErrorHandler =
               WithColor::defaultErrorHandler,
           std::function<void(Error)> WarningHandler =
               WithColor::defaultWarningHandler);
  
    /// Loads register info for the architecture of the provided object file.
    /// Improves readability of dumped DWARF expressions. Requires the caller to
    /// have initialized the relevant target descriptions.
    Error loadRegisterInfo(const object::ObjectFile &Obj);
  
    /// Get address size from CUs.
    /// TODO: refactor compile_units() to make this const.
    uint8_t getCUAddrSize();
  
    Triple::ArchType getArch() const {
      return getDWARFObj().getFile()->getArch();
    }
  
    /// Return the compile unit which contains instruction with provided
    /// address.
    /// TODO: change input parameter from "uint64_t Address"
    ///       into "SectionedAddress Address"
    DWARFCompileUnit *getCompileUnitForAddress(uint64_t Address);
  
  private:
    /// Parse a macro[.dwo] or macinfo[.dwo] section.
    std::unique_ptr<DWARFDebugMacro>
    parseMacroOrMacinfo(MacroSecType SectionType);
  
    void addLocalsForDie(DWARFCompileUnit *CU, DWARFDie Subprogram, DWARFDie Die,
                         std::vector<DILocal> &Result);
  };
  
  } // end namespace llvm
  
  #endif // LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H
  