text: //===-- SymbolFileDWARF.cpp ------------------------------------*- 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
  //
  //===----------------------------------------------------------------------===//
  
  #include "SymbolFileDWARF.h"
  
  #include "llvm/ADT/Optional.h"
  #include "llvm/Support/Casting.h"
  #include "llvm/Support/Threading.h"
  
  #include "lldb/Core/Module.h"
  #include "lldb/Core/ModuleList.h"
  #include "lldb/Core/ModuleSpec.h"
  #include "lldb/Core/PluginManager.h"
  #include "lldb/Core/Section.h"
  #include "lldb/Core/StreamFile.h"
  #include "lldb/Core/Value.h"
  #include "lldb/Utility/ArchSpec.h"
  #include "lldb/Utility/RegularExpression.h"
  #include "lldb/Utility/Scalar.h"
  #include "lldb/Utility/StreamString.h"
  #include "lldb/Utility/Timer.h"
  
  #include "Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.h"
  #include "Plugins/Language/CPlusPlus/CPlusPlusLanguage.h"
  
  #include "lldb/Host/FileSystem.h"
  #include "lldb/Host/Host.h"
  
  #include "lldb/Interpreter/OptionValueFileSpecList.h"
  #include "lldb/Interpreter/OptionValueProperties.h"
  
  #include "lldb/Symbol/Block.h"
  #include "lldb/Symbol/ClangASTContext.h"
  #include "lldb/Symbol/ClangUtil.h"
  #include "lldb/Symbol/CompileUnit.h"
  #include "lldb/Symbol/CompilerDecl.h"
  #include "lldb/Symbol/CompilerDeclContext.h"
  #include "lldb/Symbol/DebugMacros.h"
  #include "lldb/Symbol/LineTable.h"
  #include "lldb/Symbol/LocateSymbolFile.h"
  #include "lldb/Symbol/ObjectFile.h"
  #include "lldb/Symbol/SymbolFile.h"
  #include "lldb/Symbol/TypeMap.h"
  #include "lldb/Symbol/TypeSystem.h"
  #include "lldb/Symbol/VariableList.h"
  
  #include "lldb/Target/Language.h"
  #include "lldb/Target/Target.h"
  
  #include "AppleDWARFIndex.h"
  #include "DWARFASTParser.h"
  #include "DWARFASTParserClang.h"
  #include "DWARFCompileUnit.h"
  #include "DWARFDebugAbbrev.h"
  #include "DWARFDebugAranges.h"
  #include "DWARFDebugInfo.h"
  #include "DWARFDebugMacro.h"
  #include "DWARFDebugRanges.h"
  #include "DWARFDeclContext.h"
  #include "DWARFFormValue.h"
  #include "DWARFTypeUnit.h"
  #include "DWARFUnit.h"
  #include "DebugNamesDWARFIndex.h"
  #include "LogChannelDWARF.h"
  #include "ManualDWARFIndex.h"
  #include "SymbolFileDWARFDebugMap.h"
  #include "SymbolFileDWARFDwo.h"
  #include "SymbolFileDWARFDwp.h"
  
  #include "llvm/DebugInfo/DWARF/DWARFContext.h"
  #include "llvm/Support/FileSystem.h"
  
  #include <algorithm>
  #include <map>
  #include <memory>
  
  #include <ctype.h>
  #include <string.h>
  
  //#define ENABLE_DEBUG_PRINTF // COMMENT OUT THIS LINE PRIOR TO CHECKIN
  
  #ifdef ENABLE_DEBUG_PRINTF
  #include <stdio.h>
  #define DEBUG_PRINTF(fmt, ...) printf(fmt, __VA_ARGS__)
  #else
  #define DEBUG_PRINTF(fmt, ...)
  #endif
  
  using namespace lldb;
  using namespace lldb_private;
  
  char SymbolFileDWARF::ID;
  
  // static inline bool
  // child_requires_parent_class_union_or_struct_to_be_completed (dw_tag_t tag)
  //{
  //    switch (tag)
  //    {
  //    default:
  //        break;
  //    case DW_TAG_subprogram:
  //    case DW_TAG_inlined_subroutine:
  //    case DW_TAG_class_type:
  //    case DW_TAG_structure_type:
  //    case DW_TAG_union_type:
  //        return true;
  //    }
  //    return false;
  //}
  //
  
  namespace {
  
  #define LLDB_PROPERTIES_symbolfiledwarf
  #include "SymbolFileDWARFProperties.inc"
  
  enum {
  #define LLDB_PROPERTIES_symbolfiledwarf
  #include "SymbolFileDWARFPropertiesEnum.inc"
  };
  
  class PluginProperties : public Properties {
  public:
    static ConstString GetSettingName() {
      return SymbolFileDWARF::GetPluginNameStatic();
    }
  
    PluginProperties() {
      m_collection_sp = std::make_shared<OptionValueProperties>(GetSettingName());
      m_collection_sp->Initialize(g_symbolfiledwarf_properties);
    }
  
    FileSpecList GetSymLinkPaths() {
      const OptionValueFileSpecList *option_value =
          m_collection_sp->GetPropertyAtIndexAsOptionValueFileSpecList(
              nullptr, true, ePropertySymLinkPaths);
      assert(option_value);
      return option_value->GetCurrentValue();
    }
  
    bool IgnoreFileIndexes() const {
      return m_collection_sp->GetPropertyAtIndexAsBoolean(
          nullptr, ePropertyIgnoreIndexes, false);
    }
  };
  
  typedef std::shared_ptr<PluginProperties> SymbolFileDWARFPropertiesSP;
  
  static const SymbolFileDWARFPropertiesSP &GetGlobalPluginProperties() {
    static const auto g_settings_sp(std::make_shared<PluginProperties>());
    return g_settings_sp;
  }
  
  } // namespace
  
  static const llvm::DWARFDebugLine::LineTable *
  ParseLLVMLineTable(lldb_private::DWARFContext &context,
                     llvm::DWARFDebugLine &line, dw_offset_t line_offset,
                     dw_offset_t unit_offset) {
    Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
  
    llvm::DWARFDataExtractor data = context.getOrLoadLineData().GetAsLLVM();
    llvm::DWARFContext &ctx = context.GetAsLLVM();
    llvm::Expected<const llvm::DWARFDebugLine::LineTable *> line_table =
        line.getOrParseLineTable(
            data, line_offset, ctx, nullptr, [&](llvm::Error e) {
              LLDB_LOG_ERROR(log, std::move(e),
                             "SymbolFileDWARF::ParseLineTable failed to parse");
            });
  
    if (!line_table) {
      LLDB_LOG_ERROR(log, line_table.takeError(),
                     "SymbolFileDWARF::ParseLineTable failed to parse");
      return nullptr;
    }
    return *line_table;
  }
  
  static llvm::Optional<std::string>
  GetFileByIndex(const llvm::DWARFDebugLine::Prologue &prologue, size_t idx,
                 llvm::StringRef compile_dir, FileSpec::Style style) {
    // Try to get an absolute path first.
    std::string abs_path;
    auto absolute = llvm::DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath;
    if (prologue.getFileNameByIndex(idx, compile_dir, absolute, abs_path, style))
      return std::move(abs_path);
  
    // Otherwise ask for a relative path.
    std::string rel_path;
    auto relative = llvm::DILineInfoSpecifier::FileLineInfoKind::Default;
    if (!prologue.getFileNameByIndex(idx, compile_dir, relative, rel_path, style))
      return {};
    return std::move(rel_path);
  }
  
  static FileSpecList
  ParseSupportFilesFromPrologue(const lldb::ModuleSP &module,
                                const llvm::DWARFDebugLine::Prologue &prologue,
                                FileSpec::Style style,
                                llvm::StringRef compile_dir = {}) {
    FileSpecList support_files;
    size_t first_file = 0;
    if (prologue.getVersion() <= 4) {
      // File index 0 is not valid before DWARF v5. Add a dummy entry to ensure
      // support file list indices match those we get from the debug info and line
      // tables.
      support_files.Append(FileSpec());
      first_file = 1;
    }
  
    const size_t number_of_files = prologue.FileNames.size();
    for (size_t idx = first_file; idx <= number_of_files; ++idx) {
      std::string remapped_file;
      if (auto file_path = GetFileByIndex(prologue, idx, compile_dir, style))
        if (!module->RemapSourceFile(llvm::StringRef(*file_path), remapped_file))
          remapped_file = std::move(*file_path);
  
      // Unconditionally add an entry, so the indices match up.
      support_files.EmplaceBack(remapped_file, style);
    }
  
    return support_files;
  }
  
  FileSpecList SymbolFileDWARF::GetSymlinkPaths() {
    return GetGlobalPluginProperties()->GetSymLinkPaths();
  }
  
  void SymbolFileDWARF::Initialize() {
    LogChannelDWARF::Initialize();
    PluginManager::RegisterPlugin(GetPluginNameStatic(),
                                  GetPluginDescriptionStatic(), CreateInstance,
                                  DebuggerInitialize);
  }
  
  void SymbolFileDWARF::DebuggerInitialize(Debugger &debugger) {
    if (!PluginManager::GetSettingForSymbolFilePlugin(
            debugger, PluginProperties::GetSettingName())) {
      const bool is_global_setting = true;
      PluginManager::CreateSettingForSymbolFilePlugin(
          debugger, GetGlobalPluginProperties()->GetValueProperties(),
          ConstString("Properties for the dwarf symbol-file plug-in."),
          is_global_setting);
    }
  }
  
  void SymbolFileDWARF::Terminate() {
    PluginManager::UnregisterPlugin(CreateInstance);
    LogChannelDWARF::Terminate();
  }
  
  lldb_private::ConstString SymbolFileDWARF::GetPluginNameStatic() {
    static ConstString g_name("dwarf");
    return g_name;
  }
  
  const char *SymbolFileDWARF::GetPluginDescriptionStatic() {
    return "DWARF and DWARF3 debug symbol file reader.";
  }
  
  SymbolFile *SymbolFileDWARF::CreateInstance(ObjectFileSP objfile_sp) {
    return new SymbolFileDWARF(std::move(objfile_sp),
                               /*dwo_section_list*/ nullptr);
  }
  
  TypeList &SymbolFileDWARF::GetTypeList() {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    if (SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile())
      return debug_map_symfile->GetTypeList();
    return SymbolFile::GetTypeList();
  }
  void SymbolFileDWARF::GetTypes(const DWARFDIE &die, dw_offset_t min_die_offset,
                                 dw_offset_t max_die_offset, uint32_t type_mask,
                                 TypeSet &type_set) {
    if (die) {
      const dw_offset_t die_offset = die.GetOffset();
  
      if (die_offset >= max_die_offset)
        return;
  
      if (die_offset >= min_die_offset) {
        const dw_tag_t tag = die.Tag();
  
        bool add_type = false;
  
        switch (tag) {
        case DW_TAG_array_type:
          add_type = (type_mask & eTypeClassArray) != 0;
          break;
        case DW_TAG_unspecified_type:
        case DW_TAG_base_type:
          add_type = (type_mask & eTypeClassBuiltin) != 0;
          break;
        case DW_TAG_class_type:
          add_type = (type_mask & eTypeClassClass) != 0;
          break;
        case DW_TAG_structure_type:
          add_type = (type_mask & eTypeClassStruct) != 0;
          break;
        case DW_TAG_union_type:
          add_type = (type_mask & eTypeClassUnion) != 0;
          break;
        case DW_TAG_enumeration_type:
          add_type = (type_mask & eTypeClassEnumeration) != 0;
          break;
        case DW_TAG_subroutine_type:
        case DW_TAG_subprogram:
        case DW_TAG_inlined_subroutine:
          add_type = (type_mask & eTypeClassFunction) != 0;
          break;
        case DW_TAG_pointer_type:
          add_type = (type_mask & eTypeClassPointer) != 0;
          break;
        case DW_TAG_rvalue_reference_type:
        case DW_TAG_reference_type:
          add_type = (type_mask & eTypeClassReference) != 0;
          break;
        case DW_TAG_typedef:
          add_type = (type_mask & eTypeClassTypedef) != 0;
          break;
        case DW_TAG_ptr_to_member_type:
          add_type = (type_mask & eTypeClassMemberPointer) != 0;
          break;
        default:
          break;
        }
  
        if (add_type) {
          const bool assert_not_being_parsed = true;
          Type *type = ResolveTypeUID(die, assert_not_being_parsed);
          if (type) {
            if (type_set.find(type) == type_set.end())
              type_set.insert(type);
          }
        }
      }
  
      for (DWARFDIE child_die = die.GetFirstChild(); child_die.IsValid();
           child_die = child_die.GetSibling()) {
        GetTypes(child_die, min_die_offset, max_die_offset, type_mask, type_set);
      }
    }
  }
  
  void SymbolFileDWARF::GetTypes(SymbolContextScope *sc_scope,
                                 TypeClass type_mask, TypeList &type_list)
  
  {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    TypeSet type_set;
  
    CompileUnit *comp_unit = nullptr;
    DWARFUnit *dwarf_cu = nullptr;
    if (sc_scope)
      comp_unit = sc_scope->CalculateSymbolContextCompileUnit();
  
    if (comp_unit) {
      dwarf_cu = GetDWARFCompileUnit(comp_unit);
      if (!dwarf_cu)
        return;
      GetTypes(dwarf_cu->DIE(), dwarf_cu->GetOffset(),
               dwarf_cu->GetNextUnitOffset(), type_mask, type_set);
    } else {
      DWARFDebugInfo *info = DebugInfo();
      if (info) {
        const size_t num_cus = info->GetNumUnits();
        for (size_t cu_idx = 0; cu_idx < num_cus; ++cu_idx) {
          dwarf_cu = info->GetUnitAtIndex(cu_idx);
          if (dwarf_cu) {
            GetTypes(dwarf_cu->DIE(), 0, UINT32_MAX, type_mask, type_set);
          }
        }
      }
    }
  
    std::set<CompilerType> compiler_type_set;
    for (Type *type : type_set) {
      CompilerType compiler_type = type->GetForwardCompilerType();
      if (compiler_type_set.find(compiler_type) == compiler_type_set.end()) {
        compiler_type_set.insert(compiler_type);
        type_list.Insert(type->shared_from_this());
      }
    }
  }
  
  // Gets the first parent that is a lexical block, function or inlined
  // subroutine, or compile unit.
  DWARFDIE
  SymbolFileDWARF::GetParentSymbolContextDIE(const DWARFDIE &child_die) {
    DWARFDIE die;
    for (die = child_die.GetParent(); die; die = die.GetParent()) {
      dw_tag_t tag = die.Tag();
  
      switch (tag) {
      case DW_TAG_compile_unit:
      case DW_TAG_partial_unit:
      case DW_TAG_subprogram:
      case DW_TAG_inlined_subroutine:
      case DW_TAG_lexical_block:
        return die;
      default:
        break;
      }
    }
    return DWARFDIE();
  }
  
  SymbolFileDWARF::SymbolFileDWARF(ObjectFileSP objfile_sp,
                                   SectionList *dwo_section_list)
      : SymbolFile(std::move(objfile_sp)),
        UserID(0x7fffffff00000000), // Used by SymbolFileDWARFDebugMap to
                                    // when this class parses .o files to
                                    // contain the .o file index/ID
        m_debug_map_module_wp(), m_debug_map_symfile(nullptr),
        m_context(m_objfile_sp->GetModule()->GetSectionList(), dwo_section_list),
        m_data_debug_loc(), m_abbr(), m_info(), m_fetched_external_modules(false),
        m_supports_DW_AT_APPLE_objc_complete_type(eLazyBoolCalculate),
        m_unique_ast_type_map() {}
  
  SymbolFileDWARF::~SymbolFileDWARF() {}
  
  static ConstString GetDWARFMachOSegmentName() {
    static ConstString g_dwarf_section_name("__DWARF");
    return g_dwarf_section_name;
  }
  
  UniqueDWARFASTTypeMap &SymbolFileDWARF::GetUniqueDWARFASTTypeMap() {
    SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile();
    if (debug_map_symfile)
      return debug_map_symfile->GetUniqueDWARFASTTypeMap();
    else
      return m_unique_ast_type_map;
  }
  
  llvm::Expected<TypeSystem &>
  SymbolFileDWARF::GetTypeSystemForLanguage(LanguageType language) {
    if (SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile())
      return debug_map_symfile->GetTypeSystemForLanguage(language);
  
    auto type_system_or_err =
        m_objfile_sp->GetModule()->GetTypeSystemForLanguage(language);
    if (type_system_or_err) {
      type_system_or_err->SetSymbolFile(this);
    }
    return type_system_or_err;
  }
  
  void SymbolFileDWARF::InitializeObject() {
    Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
  
    if (!GetGlobalPluginProperties()->IgnoreFileIndexes()) {
      DWARFDataExtractor apple_names, apple_namespaces, apple_types, apple_objc;
      LoadSectionData(eSectionTypeDWARFAppleNames, apple_names);
      LoadSectionData(eSectionTypeDWARFAppleNamespaces, apple_namespaces);
      LoadSectionData(eSectionTypeDWARFAppleTypes, apple_types);
      LoadSectionData(eSectionTypeDWARFAppleObjC, apple_objc);
  
      m_index = AppleDWARFIndex::Create(
          *GetObjectFile()->GetModule(), apple_names, apple_namespaces,
          apple_types, apple_objc, m_context.getOrLoadStrData());
  
      if (m_index)
        return;
  
      DWARFDataExtractor debug_names;
      LoadSectionData(eSectionTypeDWARFDebugNames, debug_names);
      if (debug_names.GetByteSize() > 0) {
        llvm::Expected<std::unique_ptr<DebugNamesDWARFIndex>> index_or =
            DebugNamesDWARFIndex::Create(
                *GetObjectFile()->GetModule(), debug_names,
                m_context.getOrLoadStrData(), DebugInfo());
        if (index_or) {
          m_index = std::move(*index_or);
          return;
        }
        LLDB_LOG_ERROR(log, index_or.takeError(),
                       "Unable to read .debug_names data: {0}");
      }
    }
  
    m_index = std::make_unique<ManualDWARFIndex>(*GetObjectFile()->GetModule(),
                                                  DebugInfo());
  }
  
  bool SymbolFileDWARF::SupportedVersion(uint16_t version) {
    return version >= 2 && version <= 5;
  }
  
  uint32_t SymbolFileDWARF::CalculateAbilities() {
    uint32_t abilities = 0;
    if (m_objfile_sp != nullptr) {
      const Section *section = nullptr;
      const SectionList *section_list = m_objfile_sp->GetSectionList();
      if (section_list == nullptr)
        return 0;
  
      uint64_t debug_abbrev_file_size = 0;
      uint64_t debug_info_file_size = 0;
      uint64_t debug_line_file_size = 0;
  
      section = section_list->FindSectionByName(GetDWARFMachOSegmentName()).get();
  
      if (section)
        section_list = &section->GetChildren();
  
      section =
          section_list->FindSectionByType(eSectionTypeDWARFDebugInfo, true).get();
      if (section != nullptr) {
        debug_info_file_size = section->GetFileSize();
  
        section =
            section_list->FindSectionByType(eSectionTypeDWARFDebugAbbrev, true)
                .get();
        if (section)
          debug_abbrev_file_size = section->GetFileSize();
  
        DWARFDebugAbbrev *abbrev = DebugAbbrev();
        if (abbrev) {
          std::set<dw_form_t> invalid_forms;
          abbrev->GetUnsupportedForms(invalid_forms);
          if (!invalid_forms.empty()) {
            StreamString error;
            error.Printf("unsupported DW_FORM value%s:",
                         invalid_forms.size() > 1 ? "s" : "");
            for (auto form : invalid_forms)
              error.Printf(" %#x", form);
            m_objfile_sp->GetModule()->ReportWarning(
                "%s", error.GetString().str().c_str());
            return 0;
          }
        }
  
        section =
            section_list->FindSectionByType(eSectionTypeDWARFDebugLine, true)
                .get();
        if (section)
          debug_line_file_size = section->GetFileSize();
      } else {
        const char *symfile_dir_cstr =
            m_objfile_sp->GetFileSpec().GetDirectory().GetCString();
        if (symfile_dir_cstr) {
          if (strcasestr(symfile_dir_cstr, ".dsym")) {
            if (m_objfile_sp->GetType() == ObjectFile::eTypeDebugInfo) {
              // We have a dSYM file that didn't have a any debug info. If the
              // string table has a size of 1, then it was made from an
              // executable with no debug info, or from an executable that was
              // stripped.
              section =
                  section_list->FindSectionByType(eSectionTypeDWARFDebugStr, true)
                      .get();
              if (section && section->GetFileSize() == 1) {
                m_objfile_sp->GetModule()->ReportWarning(
                    "empty dSYM file detected, dSYM was created with an "
                    "executable with no debug info.");
              }
            }
          }
        }
      }
  
      if (debug_abbrev_file_size > 0 && debug_info_file_size > 0)
        abilities |= CompileUnits | Functions | Blocks | GlobalVariables |
                     LocalVariables | VariableTypes;
  
      if (debug_line_file_size > 0)
        abilities |= LineTables;
    }
    return abilities;
  }
  
  const DWARFDataExtractor &
  SymbolFileDWARF::GetCachedSectionData(lldb::SectionType sect_type,
                                        DWARFDataSegment &data_segment) {
    llvm::call_once(data_segment.m_flag, [this, sect_type, &data_segment] {
      this->LoadSectionData(sect_type, std::ref(data_segment.m_data));
    });
    return data_segment.m_data;
  }
  
  void SymbolFileDWARF::LoadSectionData(lldb::SectionType sect_type,
                                        DWARFDataExtractor &data) {
    ModuleSP module_sp(m_objfile_sp->GetModule());
    const SectionList *section_list = module_sp->GetSectionList();
    if (!section_list)
      return;
  
    SectionSP section_sp(section_list->FindSectionByType(sect_type, true));
    if (!section_sp)
      return;
  
    data.Clear();
    m_objfile_sp->ReadSectionData(section_sp.get(), data);
  }
  
  DWARFDebugAbbrev *SymbolFileDWARF::DebugAbbrev() {
    if (m_abbr)
      return m_abbr.get();
  
    const DWARFDataExtractor &debug_abbrev_data = m_context.getOrLoadAbbrevData();
    if (debug_abbrev_data.GetByteSize() == 0)
      return nullptr;
  
    auto abbr = std::make_unique<DWARFDebugAbbrev>();
    llvm::Error error = abbr->parse(debug_abbrev_data);
    if (error) {
      Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
      LLDB_LOG_ERROR(log, std::move(error),
                     "Unable to read .debug_abbrev section: {0}");
      return nullptr;
    }
  
    m_abbr = std::move(abbr);
    return m_abbr.get();
  }
  
  const DWARFDebugAbbrev *SymbolFileDWARF::DebugAbbrev() const {
    return m_abbr.get();
  }
  
  DWARFDebugInfo *SymbolFileDWARF::DebugInfo() {
    if (m_info == nullptr) {
      static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
      Timer scoped_timer(func_cat, "%s this = %p", LLVM_PRETTY_FUNCTION,
                         static_cast<void *>(this));
      if (m_context.getOrLoadDebugInfoData().GetByteSize() > 0)
        m_info = std::make_unique<DWARFDebugInfo>(*this, m_context);
    }
    return m_info.get();
  }
  
  const DWARFDebugInfo *SymbolFileDWARF::DebugInfo() const {
    return m_info.get();
  }
  
  DWARFUnit *
  SymbolFileDWARF::GetDWARFCompileUnit(lldb_private::CompileUnit *comp_unit) {
    if (!comp_unit)
      return nullptr;
  
    DWARFDebugInfo *info = DebugInfo();
    if (info) {
      // The compile unit ID is the index of the DWARF unit.
      DWARFUnit *dwarf_cu = info->GetUnitAtIndex(comp_unit->GetID());
      if (dwarf_cu && dwarf_cu->GetUserData() == nullptr)
        dwarf_cu->SetUserData(comp_unit);
      return dwarf_cu;
    }
    return nullptr;
  }
  
  DWARFDebugRanges *SymbolFileDWARF::GetDebugRanges() {
    if (!m_ranges) {
      static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
      Timer scoped_timer(func_cat, "%s this = %p", LLVM_PRETTY_FUNCTION,
                         static_cast<void *>(this));
  
      if (m_context.getOrLoadRangesData().GetByteSize() > 0)
        m_ranges.reset(new DWARFDebugRanges());
  
      if (m_ranges)
        m_ranges->Extract(m_context);
    }
    return m_ranges.get();
  }
  
  lldb::CompUnitSP SymbolFileDWARF::ParseCompileUnit(DWARFCompileUnit &dwarf_cu) {
    CompUnitSP cu_sp;
    CompileUnit *comp_unit = (CompileUnit *)dwarf_cu.GetUserData();
    if (comp_unit) {
      // We already parsed this compile unit, had out a shared pointer to it
      cu_sp = comp_unit->shared_from_this();
    } else {
      if (&dwarf_cu.GetSymbolFileDWARF() != this) {
        return dwarf_cu.GetSymbolFileDWARF().ParseCompileUnit(dwarf_cu);
      } else if (dwarf_cu.GetOffset() == 0 && GetDebugMapSymfile()) {
        // Let the debug map create the compile unit
        cu_sp = m_debug_map_symfile->GetCompileUnit(this);
        dwarf_cu.SetUserData(cu_sp.get());
      } else {
        ModuleSP module_sp(m_objfile_sp->GetModule());
        if (module_sp) {
          const DWARFBaseDIE cu_die =
              dwarf_cu.GetNonSkeletonUnit().GetUnitDIEOnly();
          if (cu_die) {
            FileSpec cu_file_spec(cu_die.GetName(), dwarf_cu.GetPathStyle());
            if (cu_file_spec) {
              // If we have a full path to the compile unit, we don't need to
              // resolve the file.  This can be expensive e.g. when the source
              // files are NFS mounted.
              cu_file_spec.MakeAbsolute(dwarf_cu.GetCompilationDirectory());
  
              std::string remapped_file;
              if (module_sp->RemapSourceFile(cu_file_spec.GetPath(),
                                             remapped_file))
                cu_file_spec.SetFile(remapped_file, FileSpec::Style::native);
            }
  
            LanguageType cu_language = DWARFUnit::LanguageTypeFromDWARF(
                cu_die.GetAttributeValueAsUnsigned(DW_AT_language, 0));
  
            bool is_optimized = dwarf_cu.GetNonSkeletonUnit().GetIsOptimized();
            BuildCuTranslationTable();
            cu_sp = std::make_shared<CompileUnit>(
                module_sp, &dwarf_cu, cu_file_spec,
                *GetDWARFUnitIndex(dwarf_cu.GetID()), cu_language,
                is_optimized ? eLazyBoolYes : eLazyBoolNo);
  
            dwarf_cu.SetUserData(cu_sp.get());
  
            SetCompileUnitAtIndex(dwarf_cu.GetID(), cu_sp);
          }
        }
      }
    }
    return cu_sp;
  }
  
  void SymbolFileDWARF::BuildCuTranslationTable() {
    if (!m_lldb_cu_to_dwarf_unit.empty())
      return;
  
    DWARFDebugInfo *info = DebugInfo();
    if (!info)
      return;
  
    if (!info->ContainsTypeUnits()) {
      // We can use a 1-to-1 mapping. No need to build a translation table.
      return;
    }
    for (uint32_t i = 0, num = info->GetNumUnits(); i < num; ++i) {
      if (auto *cu = llvm::dyn_cast<DWARFCompileUnit>(info->GetUnitAtIndex(i))) {
        cu->SetID(m_lldb_cu_to_dwarf_unit.size());
        m_lldb_cu_to_dwarf_unit.push_back(i);
      }
    }
  }
  
  llvm::Optional<uint32_t> SymbolFileDWARF::GetDWARFUnitIndex(uint32_t cu_idx) {
    BuildCuTranslationTable();
    if (m_lldb_cu_to_dwarf_unit.empty())
      return cu_idx;
    if (cu_idx >= m_lldb_cu_to_dwarf_unit.size())
      return llvm::None;
    return m_lldb_cu_to_dwarf_unit[cu_idx];
  }
  
  uint32_t SymbolFileDWARF::CalculateNumCompileUnits() {
    DWARFDebugInfo *info = DebugInfo();
    if (!info)
      return 0;
    BuildCuTranslationTable();
    return m_lldb_cu_to_dwarf_unit.empty() ? info->GetNumUnits()
                                           : m_lldb_cu_to_dwarf_unit.size();
  }
  
  CompUnitSP SymbolFileDWARF::ParseCompileUnitAtIndex(uint32_t cu_idx) {
    ASSERT_MODULE_LOCK(this);
    DWARFDebugInfo *info = DebugInfo();
    if (!info)
      return {};
  
    if (llvm::Optional<uint32_t> dwarf_idx = GetDWARFUnitIndex(cu_idx)) {
      if (auto *dwarf_cu = llvm::cast_or_null<DWARFCompileUnit>(
              info->GetUnitAtIndex(*dwarf_idx)))
        return ParseCompileUnit(*dwarf_cu);
    }
    return {};
  }
  
  Function *SymbolFileDWARF::ParseFunction(CompileUnit &comp_unit,
                                           const DWARFDIE &die) {
    ASSERT_MODULE_LOCK(this);
    if (!die.IsValid())
      return nullptr;
  
    auto type_system_or_err =
        GetTypeSystemForLanguage(die.GetCU()->GetLanguageType());
    if (auto err = type_system_or_err.takeError()) {
      LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
                     std::move(err), "Unable to parse function");
      return nullptr;
    }
    DWARFASTParser *dwarf_ast = type_system_or_err->GetDWARFParser();
    if (!dwarf_ast)
      return nullptr;
  
    return dwarf_ast->ParseFunctionFromDWARF(comp_unit, die);
  }
  
  bool SymbolFileDWARF::FixupAddress(Address &addr) {
    SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile();
    if (debug_map_symfile) {
      return debug_map_symfile->LinkOSOAddress(addr);
    }
    // This is a normal DWARF file, no address fixups need to happen
    return true;
  }
  lldb::LanguageType SymbolFileDWARF::ParseLanguage(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
    if (dwarf_cu)
      return dwarf_cu->GetLanguageType();
    else
      return eLanguageTypeUnknown;
  }
  
  size_t SymbolFileDWARF::ParseFunctions(CompileUnit &comp_unit) {
    static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
    Timer scoped_timer(func_cat, "SymbolFileDWARF::ParseFunctions");
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
    if (!dwarf_cu)
      return 0;
  
    size_t functions_added = 0;
    dwarf_cu = &dwarf_cu->GetNonSkeletonUnit();
    for (DWARFDebugInfoEntry &entry : dwarf_cu->dies()) {
      if (entry.Tag() != DW_TAG_subprogram)
        continue;
  
      DWARFDIE die(dwarf_cu, &entry);
      if (comp_unit.FindFunctionByUID(die.GetID()))
        continue;
      if (ParseFunction(comp_unit, die))
        ++functions_added;
    }
    // FixupTypes();
    return functions_added;
  }
  
  bool SymbolFileDWARF::ForEachExternalModule(
      CompileUnit &comp_unit,
      llvm::DenseSet<lldb_private::SymbolFile *> &visited_symbol_files,
      llvm::function_ref<bool(Module &)> lambda) {
    // Only visit each symbol file once.
    if (!visited_symbol_files.insert(this).second)
      return false;
  
    UpdateExternalModuleListIfNeeded();
    for (auto &p : m_external_type_modules) {
      ModuleSP module = p.second;
      if (!module)
        continue;
  
      // Invoke the action and potentially early-exit.
      if (lambda(*module))
        return true;
  
      for (std::size_t i = 0; i < module->GetNumCompileUnits(); ++i) {
        auto cu = module->GetCompileUnitAtIndex(i);
        bool early_exit = cu->ForEachExternalModule(visited_symbol_files, lambda);
        if (early_exit)
          return true;
      }
    }
    return false;
  }
  
  bool SymbolFileDWARF::ParseSupportFiles(CompileUnit &comp_unit,
                                          FileSpecList &support_files) {
    if (!comp_unit.GetLineTable())
      ParseLineTable(comp_unit);
    return true;
  }
  
  FileSpec SymbolFileDWARF::GetFile(DWARFUnit &unit, size_t file_idx) {
    if (auto *dwarf_cu = llvm::dyn_cast<DWARFCompileUnit>(&unit)) {
      if (CompileUnit *lldb_cu = GetCompUnitForDWARFCompUnit(*dwarf_cu))
        return lldb_cu->GetSupportFiles().GetFileSpecAtIndex(file_idx);
      return FileSpec();
    }
  
    auto &tu = llvm::cast<DWARFTypeUnit>(unit);
    return GetTypeUnitSupportFiles(tu).GetFileSpecAtIndex(file_idx);
  }
  
  const FileSpecList &
  SymbolFileDWARF::GetTypeUnitSupportFiles(DWARFTypeUnit &tu) {
    static FileSpecList empty_list;
  
    dw_offset_t offset = tu.GetLineTableOffset();
    if (offset == DW_INVALID_OFFSET ||
        offset == llvm::DenseMapInfo<dw_offset_t>::getEmptyKey() ||
        offset == llvm::DenseMapInfo<dw_offset_t>::getTombstoneKey())
      return empty_list;
  
    // Many type units can share a line table, so parse the support file list
    // once, and cache it based on the offset field.
    auto iter_bool = m_type_unit_support_files.try_emplace(offset);
    FileSpecList &list = iter_bool.first->second;
    if (iter_bool.second) {
      uint64_t line_table_offset = offset;
      llvm::DWARFDataExtractor data = m_context.getOrLoadLineData().GetAsLLVM();
      llvm::DWARFContext &ctx = m_context.GetAsLLVM();
      llvm::DWARFDebugLine::Prologue prologue;
      llvm::Error error = prologue.parse(data, &line_table_offset, ctx);
      if (error) {
        Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
        LLDB_LOG_ERROR(log, std::move(error),
                       "SymbolFileDWARF::GetTypeUnitSupportFiles failed to parse "
                       "the line table prologue");
      } else {
        list = ParseSupportFilesFromPrologue(GetObjectFile()->GetModule(),
                                             prologue, tu.GetPathStyle());
      }
    }
    return list;
  }
  
  bool SymbolFileDWARF::ParseIsOptimized(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
    if (dwarf_cu)
      return dwarf_cu->GetIsOptimized();
    return false;
  }
  
  bool SymbolFileDWARF::ParseImportedModules(
      const lldb_private::SymbolContext &sc,
      std::vector<SourceModule> &imported_modules) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    assert(sc.comp_unit);
    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(sc.comp_unit);
    if (!dwarf_cu)
      return false;
    if (!ClangModulesDeclVendor::LanguageSupportsClangModules(
            sc.comp_unit->GetLanguage()))
      return false;
    UpdateExternalModuleListIfNeeded();
  
    const DWARFDIE die = dwarf_cu->DIE();
    if (!die)
      return false;
  
    for (DWARFDIE child_die = die.GetFirstChild(); child_die;
         child_die = child_die.GetSibling()) {
      if (child_die.Tag() != DW_TAG_imported_declaration)
        continue;
  
      DWARFDIE module_die = child_die.GetReferencedDIE(DW_AT_import);
      if (module_die.Tag() != DW_TAG_module)
        continue;
  
      if (const char *name =
              module_die.GetAttributeValueAsString(DW_AT_name, nullptr)) {
        SourceModule module;
        module.path.push_back(ConstString(name));
  
        DWARFDIE parent_die = module_die;
        while ((parent_die = parent_die.GetParent())) {
          if (parent_die.Tag() != DW_TAG_module)
            break;
          if (const char *name =
                  parent_die.GetAttributeValueAsString(DW_AT_name, nullptr))
            module.path.push_back(ConstString(name));
        }
        std::reverse(module.path.begin(), module.path.end());
        if (const char *include_path = module_die.GetAttributeValueAsString(
                DW_AT_LLVM_include_path, nullptr))
          module.search_path = ConstString(include_path);
        if (const char *sysroot = module_die.GetAttributeValueAsString(
                DW_AT_LLVM_sysroot, nullptr))
          module.sysroot = ConstString(sysroot);
        imported_modules.push_back(module);
      }
    }
    return true;
  }
  
  bool SymbolFileDWARF::ParseLineTable(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    if (comp_unit.GetLineTable() != nullptr)
      return true;
  
    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
    if (!dwarf_cu)
      return false;
  
    const DWARFBaseDIE dwarf_cu_die = dwarf_cu->GetUnitDIEOnly();
    if (!dwarf_cu_die)
      return false;
  
    const dw_offset_t cu_line_offset = dwarf_cu_die.GetAttributeValueAsUnsigned(
        DW_AT_stmt_list, DW_INVALID_OFFSET);
    if (cu_line_offset == DW_INVALID_OFFSET)
      return false;
  
    llvm::DWARFDebugLine line;
    const llvm::DWARFDebugLine::LineTable *line_table = ParseLLVMLineTable(
        m_context, line, cu_line_offset, dwarf_cu->GetOffset());
  
    if (!line_table)
      return false;
  
    // FIXME: Rather than parsing the whole line table and then copying it over
    // into LLDB, we should explore using a callback to populate the line table
    // while we parse to reduce memory usage.
    std::unique_ptr<LineTable> line_table_up =
        std::make_unique<LineTable>(&comp_unit);
    LineSequence *sequence = line_table_up->CreateLineSequenceContainer();
    for (auto &row : line_table->Rows) {
      line_table_up->AppendLineEntryToSequence(
          sequence, row.Address.Address, row.Line, row.Column, row.File,
          row.IsStmt, row.BasicBlock, row.PrologueEnd, row.EpilogueBegin,
          row.EndSequence);
      if (row.EndSequence) {
        line_table_up->InsertSequence(sequence);
        sequence = line_table_up->CreateLineSequenceContainer();
      }
    }
  
    if (SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile()) {
      // We have an object file that has a line table with addresses that are not
      // linked. We need to link the line table and convert the addresses that
      // are relative to the .o file into addresses for the main executable.
      comp_unit.SetLineTable(
          debug_map_symfile->LinkOSOLineTable(this, line_table_up.get()));
    } else {
      comp_unit.SetLineTable(line_table_up.release());
    }
  
    comp_unit.SetSupportFiles(ParseSupportFilesFromPrologue(
        comp_unit.GetModule(), line_table->Prologue, dwarf_cu->GetPathStyle(),
        dwarf_cu->GetCompilationDirectory().GetCString()));
  
    return true;
  }
  
  lldb_private::DebugMacrosSP
  SymbolFileDWARF::ParseDebugMacros(lldb::offset_t *offset) {
    auto iter = m_debug_macros_map.find(*offset);
    if (iter != m_debug_macros_map.end())
      return iter->second;
  
    const DWARFDataExtractor &debug_macro_data = m_context.getOrLoadMacroData();
    if (debug_macro_data.GetByteSize() == 0)
      return DebugMacrosSP();
  
    lldb_private::DebugMacrosSP debug_macros_sp(new lldb_private::DebugMacros());
    m_debug_macros_map[*offset] = debug_macros_sp;
  
    const DWARFDebugMacroHeader &header =
        DWARFDebugMacroHeader::ParseHeader(debug_macro_data, offset);
    DWARFDebugMacroEntry::ReadMacroEntries(
        debug_macro_data, m_context.getOrLoadStrData(), header.OffsetIs64Bit(),
        offset, this, debug_macros_sp);
  
    return debug_macros_sp;
  }
  
  bool SymbolFileDWARF::ParseDebugMacros(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
  
    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
    if (dwarf_cu == nullptr)
      return false;
  
    const DWARFBaseDIE dwarf_cu_die = dwarf_cu->GetUnitDIEOnly();
    if (!dwarf_cu_die)
      return false;
  
    lldb::offset_t sect_offset =
        dwarf_cu_die.GetAttributeValueAsUnsigned(DW_AT_macros, DW_INVALID_OFFSET);
    if (sect_offset == DW_INVALID_OFFSET)
      sect_offset = dwarf_cu_die.GetAttributeValueAsUnsigned(DW_AT_GNU_macros,
                                                             DW_INVALID_OFFSET);
    if (sect_offset == DW_INVALID_OFFSET)
      return false;
  
    comp_unit.SetDebugMacros(ParseDebugMacros(&sect_offset));
  
    return true;
  }
  
  size_t SymbolFileDWARF::ParseBlocksRecursive(
      lldb_private::CompileUnit &comp_unit, Block *parent_block,
      const DWARFDIE &orig_die, addr_t subprogram_low_pc, uint32_t depth) {
    size_t blocks_added = 0;
    DWARFDIE die = orig_die;
    while (die) {
      dw_tag_t tag = die.Tag();
  
      switch (tag) {
      case DW_TAG_inlined_subroutine:
      case DW_TAG_subprogram:
      case DW_TAG_lexical_block: {
        Block *block = nullptr;
        if (tag == DW_TAG_subprogram) {
          // Skip any DW_TAG_subprogram DIEs that are inside of a normal or
          // inlined functions. These will be parsed on their own as separate
          // entities.
  
          if (depth > 0)
            break;
  
          block = parent_block;
        } else {
          BlockSP block_sp(new Block(die.GetID()));
          parent_block->AddChild(block_sp);
          block = block_sp.get();
        }
        DWARFRangeList ranges;
        const char *name = nullptr;
        const char *mangled_name = nullptr;
  
        int decl_file = 0;
        int decl_line = 0;
        int decl_column = 0;
        int call_file = 0;
        int call_line = 0;
        int call_column = 0;
        if (die.GetDIENamesAndRanges(name, mangled_name, ranges, decl_file,
                                     decl_line, decl_column, call_file, call_line,
                                     call_column, nullptr)) {
          if (tag == DW_TAG_subprogram) {
            assert(subprogram_low_pc == LLDB_INVALID_ADDRESS);
            subprogram_low_pc = ranges.GetMinRangeBase(0);
          } else if (tag == DW_TAG_inlined_subroutine) {
            // We get called here for inlined subroutines in two ways. The first
            // time is when we are making the Function object for this inlined
            // concrete instance.  Since we're creating a top level block at
            // here, the subprogram_low_pc will be LLDB_INVALID_ADDRESS.  So we
            // need to adjust the containing address. The second time is when we
            // are parsing the blocks inside the function that contains the
            // inlined concrete instance.  Since these will be blocks inside the
            // containing "real" function the offset will be for that function.
            if (subprogram_low_pc == LLDB_INVALID_ADDRESS) {
              subprogram_low_pc = ranges.GetMinRangeBase(0);
            }
          }
  
          const size_t num_ranges = ranges.GetSize();
          for (size_t i = 0; i < num_ranges; ++i) {
            const DWARFRangeList::Entry &range = ranges.GetEntryRef(i);
            const addr_t range_base = range.GetRangeBase();
            if (range_base >= subprogram_low_pc)
              block->AddRange(Block::Range(range_base - subprogram_low_pc,
                                           range.GetByteSize()));
            else {
              GetObjectFile()->GetModule()->ReportError(
                  "0x%8.8" PRIx64 ": adding range [0x%" PRIx64 "-0x%" PRIx64
                  ") which has a base that is less than the function's low PC "
                  "0x%" PRIx64 ". Please file a bug and attach the file at the "
                  "start of this error message",
                  block->GetID(), range_base, range.GetRangeEnd(),
                  subprogram_low_pc);
            }
          }
          block->FinalizeRanges();
  
          if (tag != DW_TAG_subprogram &&
              (name != nullptr || mangled_name != nullptr)) {
            std::unique_ptr<Declaration> decl_up;
            if (decl_file != 0 || decl_line != 0 || decl_column != 0)
              decl_up.reset(new Declaration(
                  comp_unit.GetSupportFiles().GetFileSpecAtIndex(decl_file),
                  decl_line, decl_column));
  
            std::unique_ptr<Declaration> call_up;
            if (call_file != 0 || call_line != 0 || call_column != 0)
              call_up.reset(new Declaration(
                  comp_unit.GetSupportFiles().GetFileSpecAtIndex(call_file),
                  call_line, call_column));
  
            block->SetInlinedFunctionInfo(name, mangled_name, decl_up.get(),
                                          call_up.get());
          }
  
          ++blocks_added;
  
          if (die.HasChildren()) {
            blocks_added +=
                ParseBlocksRecursive(comp_unit, block, die.GetFirstChild(),
                                     subprogram_low_pc, depth + 1);
          }
        }
      } break;
      default:
        break;
      }
  
      // Only parse siblings of the block if we are not at depth zero. A depth of
      // zero indicates we are currently parsing the top level DW_TAG_subprogram
      // DIE
  
      if (depth == 0)
        die.Clear();
      else
        die = die.GetSibling();
    }
    return blocks_added;
  }
  
  bool SymbolFileDWARF::ClassOrStructIsVirtual(const DWARFDIE &parent_die) {
    if (parent_die) {
      for (DWARFDIE die = parent_die.GetFirstChild(); die;
           die = die.GetSibling()) {
        dw_tag_t tag = die.Tag();
        bool check_virtuality = false;
        switch (tag) {
        case DW_TAG_inheritance:
        case DW_TAG_subprogram:
          check_virtuality = true;
          break;
        default:
          break;
        }
        if (check_virtuality) {
          if (die.GetAttributeValueAsUnsigned(DW_AT_virtuality, 0) != 0)
            return true;
        }
      }
    }
    return false;
  }
  
  void SymbolFileDWARF::ParseDeclsForContext(CompilerDeclContext decl_ctx) {
    auto *type_system = decl_ctx.GetTypeSystem();
    if (type_system != nullptr)
      type_system->GetDWARFParser()->EnsureAllDIEsInDeclContextHaveBeenParsed(
          decl_ctx);
  }
  
  user_id_t SymbolFileDWARF::GetUID(DIERef ref) {
    if (GetDebugMapSymfile())
      return GetID() | ref.die_offset();
  
    return user_id_t(GetDwoNum().getValueOr(0x7fffffff)) << 32 |
           ref.die_offset() |
           (lldb::user_id_t(ref.section() == DIERef::Section::DebugTypes) << 63);
  }
  
  llvm::Optional<SymbolFileDWARF::DecodedUID>
  SymbolFileDWARF::DecodeUID(lldb::user_id_t uid) {
    // This method can be called without going through the symbol vendor so we
    // need to lock the module.
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    // Anytime we get a "lldb::user_id_t" from an lldb_private::SymbolFile API we
    // must make sure we use the correct DWARF file when resolving things. On
    // MacOSX, when using SymbolFileDWARFDebugMap, we will use multiple
    // SymbolFileDWARF classes, one for each .o file. We can often end up with
    // references to other DWARF objects and we must be ready to receive a
    // "lldb::user_id_t" that specifies a DIE from another SymbolFileDWARF
    // instance.
    if (SymbolFileDWARFDebugMap *debug_map = GetDebugMapSymfile()) {
      SymbolFileDWARF *dwarf = debug_map->GetSymbolFileByOSOIndex(
          debug_map->GetOSOIndexFromUserID(uid));
      return DecodedUID{
          *dwarf, {llvm::None, DIERef::Section::DebugInfo, dw_offset_t(uid)}};
    }
    dw_offset_t die_offset = uid;
    if (die_offset == DW_INVALID_OFFSET)
      return llvm::None;
  
    DIERef::Section section =
        uid >> 63 ? DIERef::Section::DebugTypes : DIERef::Section::DebugInfo;
  
    llvm::Optional<uint32_t> dwo_num = uid >> 32 & 0x7fffffff;
    if (*dwo_num == 0x7fffffff)
      dwo_num = llvm::None;
  
    return DecodedUID{*this, {dwo_num, section, die_offset}};
  }
  
  DWARFDIE
  SymbolFileDWARF::GetDIE(lldb::user_id_t uid) {
    // This method can be called without going through the symbol vendor so we
    // need to lock the module.
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
  
    llvm::Optional<DecodedUID> decoded = DecodeUID(uid);
  
    if (decoded)
      return decoded->dwarf.GetDIE(decoded->ref);
  
    return DWARFDIE();
  }
  
  CompilerDecl SymbolFileDWARF::GetDeclForUID(lldb::user_id_t type_uid) {
    // This method can be called without going through the symbol vendor so we
    // need to lock the module.
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    // Anytime we have a lldb::user_id_t, we must get the DIE by calling
    // SymbolFileDWARF::GetDIE(). See comments inside the
    // SymbolFileDWARF::GetDIE() for details.
    if (DWARFDIE die = GetDIE(type_uid))
      return die.GetDecl();
    return CompilerDecl();
  }
  
  CompilerDeclContext
  SymbolFileDWARF::GetDeclContextForUID(lldb::user_id_t type_uid) {
    // This method can be called without going through the symbol vendor so we
    // need to lock the module.
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    // Anytime we have a lldb::user_id_t, we must get the DIE by calling
    // SymbolFileDWARF::GetDIE(). See comments inside the
    // SymbolFileDWARF::GetDIE() for details.
    if (DWARFDIE die = GetDIE(type_uid))
      return die.GetDeclContext();
    return CompilerDeclContext();
  }
  
  CompilerDeclContext
  SymbolFileDWARF::GetDeclContextContainingUID(lldb::user_id_t type_uid) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    // Anytime we have a lldb::user_id_t, we must get the DIE by calling
    // SymbolFileDWARF::GetDIE(). See comments inside the
    // SymbolFileDWARF::GetDIE() for details.
    if (DWARFDIE die = GetDIE(type_uid))
      return die.GetContainingDeclContext();
    return CompilerDeclContext();
  }
  
  Type *SymbolFileDWARF::ResolveTypeUID(lldb::user_id_t type_uid) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    // Anytime we have a lldb::user_id_t, we must get the DIE by calling
    // SymbolFileDWARF::GetDIE(). See comments inside the
    // SymbolFileDWARF::GetDIE() for details.
    if (DWARFDIE type_die = GetDIE(type_uid))
      return type_die.ResolveType();
    else
      return nullptr;
  }
  
  llvm::Optional<SymbolFile::ArrayInfo>
  SymbolFileDWARF::GetDynamicArrayInfoForUID(
      lldb::user_id_t type_uid, const lldb_private::ExecutionContext *exe_ctx) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    if (DWARFDIE type_die = GetDIE(type_uid))
      return DWARFASTParser::ParseChildArrayInfo(type_die, exe_ctx);
    else
      return llvm::None;
  }
  
  Type *SymbolFileDWARF::ResolveTypeUID(const DIERef &die_ref) {
    return ResolveType(GetDIE(die_ref), true);
  }
  
  Type *SymbolFileDWARF::ResolveTypeUID(const DWARFDIE &die,
                                        bool assert_not_being_parsed) {
    if (die) {
      Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO));
      if (log)
        GetObjectFile()->GetModule()->LogMessage(
            log, "SymbolFileDWARF::ResolveTypeUID (die = 0x%8.8x) %s '%s'",
            die.GetOffset(), die.GetTagAsCString(), die.GetName());
  
      // We might be coming in in the middle of a type tree (a class within a
      // class, an enum within a class), so parse any needed parent DIEs before
      // we get to this one...
      DWARFDIE decl_ctx_die = GetDeclContextDIEContainingDIE(die);
      if (decl_ctx_die) {
        if (log) {
          switch (decl_ctx_die.Tag()) {
          case DW_TAG_structure_type:
          case DW_TAG_union_type:
          case DW_TAG_class_type: {
            // Get the type, which could be a forward declaration
            if (log)
              GetObjectFile()->GetModule()->LogMessage(
                  log,
                  "SymbolFileDWARF::ResolveTypeUID (die = 0x%8.8x) %s '%s' "
                  "resolve parent forward type for 0x%8.8x",
                  die.GetOffset(), die.GetTagAsCString(), die.GetName(),
                  decl_ctx_die.GetOffset());
          } break;
  
          default:
            break;
          }
        }
      }
      return ResolveType(die);
    }
    return nullptr;
  }
  
  // This function is used when SymbolFileDWARFDebugMap owns a bunch of
  // SymbolFileDWARF objects to detect if this DWARF file is the one that can
  // resolve a compiler_type.
  bool SymbolFileDWARF::HasForwardDeclForClangType(
      const CompilerType &compiler_type) {
    CompilerType compiler_type_no_qualifiers =
        ClangUtil::RemoveFastQualifiers(compiler_type);
    if (GetForwardDeclClangTypeToDie().count(
            compiler_type_no_qualifiers.GetOpaqueQualType())) {
      return true;
    }
    TypeSystem *type_system = compiler_type.GetTypeSystem();
  
    ClangASTContext *clang_type_system =
        llvm::dyn_cast_or_null<ClangASTContext>(type_system);
    if (!clang_type_system)
      return false;
    DWARFASTParserClang *ast_parser =
        static_cast<DWARFASTParserClang *>(clang_type_system->GetDWARFParser());
    return ast_parser->GetClangASTImporter().CanImport(compiler_type);
  }
  
  bool SymbolFileDWARF::CompleteType(CompilerType &compiler_type) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
  
    ClangASTContext *clang_type_system =
        llvm::dyn_cast_or_null<ClangASTContext>(compiler_type.GetTypeSystem());
    if (clang_type_system) {
      DWARFASTParserClang *ast_parser =
          static_cast<DWARFASTParserClang *>(clang_type_system->GetDWARFParser());
      if (ast_parser &&
          ast_parser->GetClangASTImporter().CanImport(compiler_type))
        return ast_parser->GetClangASTImporter().CompleteType(compiler_type);
    }
  
    // We have a struct/union/class/enum that needs to be fully resolved.
    CompilerType compiler_type_no_qualifiers =
        ClangUtil::RemoveFastQualifiers(compiler_type);
    auto die_it = GetForwardDeclClangTypeToDie().find(
        compiler_type_no_qualifiers.GetOpaqueQualType());
    if (die_it == GetForwardDeclClangTypeToDie().end()) {
      // We have already resolved this type...
      return true;
    }
  
    DWARFDIE dwarf_die = GetDIE(die_it->getSecond());
    if (dwarf_die) {
      // Once we start resolving this type, remove it from the forward
      // declaration map in case anyone child members or other types require this
      // type to get resolved. The type will get resolved when all of the calls
      // to SymbolFileDWARF::ResolveClangOpaqueTypeDefinition are done.
      GetForwardDeclClangTypeToDie().erase(die_it);
  
      Type *type = GetDIEToType().lookup(dwarf_die.GetDIE());
  
      Log *log(LogChannelDWARF::GetLogIfAny(DWARF_LOG_DEBUG_INFO |
                                            DWARF_LOG_TYPE_COMPLETION));
      if (log)
        GetObjectFile()->GetModule()->LogMessageVerboseBacktrace(
            log, "0x%8.8" PRIx64 ": %s '%s' resolving forward declaration...",
            dwarf_die.GetID(), dwarf_die.GetTagAsCString(),
            type->GetName().AsCString());
      assert(compiler_type);
      DWARFASTParser *dwarf_ast = dwarf_die.GetDWARFParser();
      if (dwarf_ast)
        return dwarf_ast->CompleteTypeFromDWARF(dwarf_die, type, compiler_type);
    }
    return false;
  }
  
  Type *SymbolFileDWARF::ResolveType(const DWARFDIE &die,
                                     bool assert_not_being_parsed,
                                     bool resolve_function_context) {
    if (die) {
      Type *type = GetTypeForDIE(die, resolve_function_context).get();
  
      if (assert_not_being_parsed) {
        if (type != DIE_IS_BEING_PARSED)
          return type;
  
        GetObjectFile()->GetModule()->ReportError(
            "Parsing a die that is being parsed die: 0x%8.8x: %s %s",
            die.GetOffset(), die.GetTagAsCString(), die.GetName());
  
      } else
        return type;
    }
    return nullptr;
  }
  
  CompileUnit *
  SymbolFileDWARF::GetCompUnitForDWARFCompUnit(DWARFCompileUnit &dwarf_cu) {
    // Check if the symbol vendor already knows about this compile unit?
    if (dwarf_cu.GetUserData() == nullptr) {
      // The symbol vendor doesn't know about this compile unit, we need to parse
      // and add it to the symbol vendor object.
      return ParseCompileUnit(dwarf_cu).get();
    }
    return (CompileUnit *)dwarf_cu.GetUserData();
  }
  
  size_t SymbolFileDWARF::GetObjCMethodDIEOffsets(ConstString class_name,
                                                  DIEArray &method_die_offsets) {
    method_die_offsets.clear();
    m_index->GetObjCMethods(class_name, method_die_offsets);
    return method_die_offsets.size();
  }
  
  bool SymbolFileDWARF::GetFunction(const DWARFDIE &die, SymbolContext &sc) {
    sc.Clear(false);
  
    if (die && llvm::isa<DWARFCompileUnit>(die.GetCU())) {
      // Check if the symbol vendor already knows about this compile unit?
      sc.comp_unit =
          GetCompUnitForDWARFCompUnit(llvm::cast<DWARFCompileUnit>(*die.GetCU()));
  
      sc.function = sc.comp_unit->FindFunctionByUID(die.GetID()).get();
      if (sc.function == nullptr)
        sc.function = ParseFunction(*sc.comp_unit, die);
  
      if (sc.function) {
        sc.module_sp = sc.function->CalculateSymbolContextModule();
        return true;
      }
    }
  
    return false;
  }
  
  lldb::ModuleSP SymbolFileDWARF::GetExternalModule(ConstString name) {
    UpdateExternalModuleListIfNeeded();
    const auto &pos = m_external_type_modules.find(name);
    if (pos != m_external_type_modules.end())
      return pos->second;
    else
      return lldb::ModuleSP();
  }
  
  DWARFDIE
  SymbolFileDWARF::GetDIE(const DIERef &die_ref) {
    if (die_ref.dwo_num()) {
      return DebugInfo()
          ->GetUnitAtIndex(*die_ref.dwo_num())
          ->GetDwoSymbolFile()
          ->GetDIE(die_ref);
    }
  
    DWARFDebugInfo *debug_info = DebugInfo();
    if (debug_info)
      return debug_info->GetDIE(die_ref);
    else
      return DWARFDIE();
  }
  
  /// Return the DW_AT_(GNU_)dwo_name.
  static const char *GetDWOName(DWARFCompileUnit &dwarf_cu,
                                const DWARFDebugInfoEntry &cu_die) {
    const char *dwo_name =
        cu_die.GetAttributeValueAsString(&dwarf_cu, DW_AT_GNU_dwo_name, nullptr);
    if (!dwo_name)
      dwo_name =
          cu_die.GetAttributeValueAsString(&dwarf_cu, DW_AT_dwo_name, nullptr);
    return dwo_name;
  }
  
  /// Return the DW_AT_(GNU_)dwo_id.
  /// FIXME: Technically 0 is a valid hash.
  static uint64_t GetDWOId(DWARFCompileUnit &dwarf_cu,
                           const DWARFDebugInfoEntry &cu_die) {
    uint64_t dwo_id =
        cu_die.GetAttributeValueAsUnsigned(&dwarf_cu, DW_AT_GNU_dwo_id, 0);
    if (!dwo_id)
      dwo_id = cu_die.GetAttributeValueAsUnsigned(&dwarf_cu, DW_AT_dwo_id, 0);
    return dwo_id;
  }
  
  llvm::Optional<uint64_t> SymbolFileDWARF::GetDWOId() {
    if (GetNumCompileUnits() == 1) {
      if (auto comp_unit = GetCompileUnitAtIndex(0))
        if (DWARFCompileUnit *cu = llvm::dyn_cast_or_null<DWARFCompileUnit>(
                GetDWARFCompileUnit(comp_unit.get())))
          if (DWARFDebugInfoEntry *cu_die = cu->DIE().GetDIE())
            if (uint64_t dwo_id = ::GetDWOId(*cu, *cu_die))
              return dwo_id;
    }
    return {};
  }
  
  std::unique_ptr<SymbolFileDWARFDwo>
  SymbolFileDWARF::GetDwoSymbolFileForCompileUnit(
      DWARFUnit &unit, const DWARFDebugInfoEntry &cu_die) {
    // If this is a Darwin-style debug map (non-.dSYM) symbol file,
    // never attempt to load ELF-style DWO files since the -gmodules
    // support uses the same DWO machanism to specify full debug info
    // files for modules. This is handled in
    // UpdateExternalModuleListIfNeeded().
    if (GetDebugMapSymfile())
      return nullptr;
  
    DWARFCompileUnit *dwarf_cu = llvm::dyn_cast<DWARFCompileUnit>(&unit);
    // Only compile units can be split into two parts.
    if (!dwarf_cu)
      return nullptr;
  
    const char *dwo_name = GetDWOName(*dwarf_cu, cu_die);
    if (!dwo_name)
      return nullptr;
  
    SymbolFileDWARFDwp *dwp_symfile = GetDwpSymbolFile();
    if (dwp_symfile) {
      uint64_t dwo_id = ::GetDWOId(*dwarf_cu, cu_die);
      std::unique_ptr<SymbolFileDWARFDwo> dwo_symfile =
          dwp_symfile->GetSymbolFileForDwoId(*dwarf_cu, dwo_id);
      if (dwo_symfile)
        return dwo_symfile;
    }
  
    FileSpec dwo_file(dwo_name);
    FileSystem::Instance().Resolve(dwo_file);
    if (dwo_file.IsRelative()) {
      const char *comp_dir =
          cu_die.GetAttributeValueAsString(dwarf_cu, DW_AT_comp_dir, nullptr);
      if (!comp_dir)
        return nullptr;
  
      dwo_file.SetFile(comp_dir, FileSpec::Style::native);
      FileSystem::Instance().Resolve(dwo_file);
      dwo_file.AppendPathComponent(dwo_name);
    }
  
    if (!FileSystem::Instance().Exists(dwo_file))
      return nullptr;
  
    const lldb::offset_t file_offset = 0;
    DataBufferSP dwo_file_data_sp;
    lldb::offset_t dwo_file_data_offset = 0;
    ObjectFileSP dwo_obj_file = ObjectFile::FindPlugin(
        GetObjectFile()->GetModule(), &dwo_file, file_offset,
        FileSystem::Instance().GetByteSize(dwo_file), dwo_file_data_sp,
        dwo_file_data_offset);
    if (dwo_obj_file == nullptr)
      return nullptr;
  
    return std::make_unique<SymbolFileDWARFDwo>(dwo_obj_file, *dwarf_cu);
  }
  
  void SymbolFileDWARF::UpdateExternalModuleListIfNeeded() {
    if (m_fetched_external_modules)
      return;
    m_fetched_external_modules = true;
    DWARFDebugInfo *debug_info = DebugInfo();
  
    // Follow DWO skeleton unit breadcrumbs.
    const uint32_t num_compile_units = GetNumCompileUnits();
    for (uint32_t cu_idx = 0; cu_idx < num_compile_units; ++cu_idx) {
      auto *dwarf_cu =
          llvm::dyn_cast<DWARFCompileUnit>(debug_info->GetUnitAtIndex(cu_idx));
      if (!dwarf_cu)
        continue;
  
      const DWARFBaseDIE die = dwarf_cu->GetUnitDIEOnly();
      if (!die || die.HasChildren() || !die.GetDIE())
        continue;
  
      const char *name = die.GetAttributeValueAsString(DW_AT_name, nullptr);
      if (!name)
        continue;
  
      ConstString const_name(name);
      ModuleSP &module_sp = m_external_type_modules[const_name];
      if (module_sp)
        continue;
  
      const char *dwo_path = GetDWOName(*dwarf_cu, *die.GetDIE());
      if (!dwo_path)
        continue;
  
      ModuleSpec dwo_module_spec;
      dwo_module_spec.GetFileSpec().SetFile(dwo_path, FileSpec::Style::native);
      if (dwo_module_spec.GetFileSpec().IsRelative()) {
        const char *comp_dir =
            die.GetAttributeValueAsString(DW_AT_comp_dir, nullptr);
        if (comp_dir) {
          dwo_module_spec.GetFileSpec().SetFile(comp_dir,
                                                FileSpec::Style::native);
          FileSystem::Instance().Resolve(dwo_module_spec.GetFileSpec());
          dwo_module_spec.GetFileSpec().AppendPathComponent(dwo_path);
        }
      }
      dwo_module_spec.GetArchitecture() =
          m_objfile_sp->GetModule()->GetArchitecture();
  
      // When LLDB loads "external" modules it looks at the presence of
      // DW_AT_dwo_name. However, when the already created module
      // (corresponding to .dwo itself) is being processed, it will see
      // the presence of DW_AT_dwo_name (which contains the name of dwo
      // file) and will try to call ModuleList::GetSharedModule
      // again. In some cases (i.e., for empty files) Clang 4.0
      // generates a *.dwo file which has DW_AT_dwo_name, but no
      // DW_AT_comp_dir. In this case the method
      // ModuleList::GetSharedModule will fail and the warning will be
      // printed. However, as one can notice in this case we don't
      // actually need to try to load the already loaded module
      // (corresponding to .dwo) so we simply skip it.
      if (m_objfile_sp->GetFileSpec().GetFileNameExtension() == ".dwo" &&
          llvm::StringRef(m_objfile_sp->GetFileSpec().GetPath())
              .endswith(dwo_module_spec.GetFileSpec().GetPath())) {
        continue;
      }
  
      Status error = ModuleList::GetSharedModule(dwo_module_spec, module_sp,
                                                 nullptr, nullptr, nullptr);
      if (!module_sp) {
        GetObjectFile()->GetModule()->ReportWarning(
            "0x%8.8x: unable to locate module needed for external types: "
            "%s\nerror: %s\nDebugging will be degraded due to missing "
            "types. Rebuilding the project will regenerate the needed "
            "module files.",
            die.GetOffset(), dwo_module_spec.GetFileSpec().GetPath().c_str(),
            error.AsCString("unknown error"));
        continue;
      }
  
      // Verify the DWO hash.
      // FIXME: Technically "0" is a valid hash.
      uint64_t dwo_id = ::GetDWOId(*dwarf_cu, *die.GetDIE());
      if (!dwo_id)
        continue;
  
      auto *dwo_symfile =
          llvm::dyn_cast_or_null<SymbolFileDWARF>(module_sp->GetSymbolFile());
      if (!dwo_symfile)
        continue;
      llvm::Optional<uint64_t> dwo_dwo_id = dwo_symfile->GetDWOId();
      if (!dwo_dwo_id)
        continue;
  
      if (dwo_id != dwo_dwo_id) {
        GetObjectFile()->GetModule()->ReportWarning(
            "0x%8.8x: Module %s is out-of-date (hash mismatch). Type information "
            "from this module may be incomplete or inconsistent with the rest of "
            "the program. Rebuilding the project will regenerate the needed "
            "module files.",
            die.GetOffset(), dwo_module_spec.GetFileSpec().GetPath().c_str());
      }
    }
  }
  
  SymbolFileDWARF::GlobalVariableMap &SymbolFileDWARF::GetGlobalAranges() {
    if (!m_global_aranges_up) {
      m_global_aranges_up.reset(new GlobalVariableMap());
  
      ModuleSP module_sp = GetObjectFile()->GetModule();
      if (module_sp) {
        const size_t num_cus = module_sp->GetNumCompileUnits();
        for (size_t i = 0; i < num_cus; ++i) {
          CompUnitSP cu_sp = module_sp->GetCompileUnitAtIndex(i);
          if (cu_sp) {
            VariableListSP globals_sp = cu_sp->GetVariableList(true);
            if (globals_sp) {
              const size_t num_globals = globals_sp->GetSize();
              for (size_t g = 0; g < num_globals; ++g) {
                VariableSP var_sp = globals_sp->GetVariableAtIndex(g);
                if (var_sp && !var_sp->GetLocationIsConstantValueData()) {
                  const DWARFExpression &location = var_sp->LocationExpression();
                  Value location_result;
                  Status error;
                  if (location.Evaluate(nullptr, LLDB_INVALID_ADDRESS, nullptr,
                                        nullptr, location_result, &error)) {
                    if (location_result.GetValueType() ==
                        Value::eValueTypeFileAddress) {
                      lldb::addr_t file_addr =
                          location_result.GetScalar().ULongLong();
                      lldb::addr_t byte_size = 1;
                      if (var_sp->GetType())
                        byte_size =
                            var_sp->GetType()->GetByteSize().getValueOr(0);
                      m_global_aranges_up->Append(GlobalVariableMap::Entry(
                          file_addr, byte_size, var_sp.get()));
                    }
                  }
                }
              }
            }
          }
        }
      }
      m_global_aranges_up->Sort();
    }
    return *m_global_aranges_up;
  }
  
  uint32_t SymbolFileDWARF::ResolveSymbolContext(const Address &so_addr,
                                                 SymbolContextItem resolve_scope,
                                                 SymbolContext &sc) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
    Timer scoped_timer(func_cat,
                       "SymbolFileDWARF::"
                       "ResolveSymbolContext (so_addr = { "
                       "section = %p, offset = 0x%" PRIx64
                       " }, resolve_scope = 0x%8.8x)",
                       static_cast<void *>(so_addr.GetSection().get()),
                       so_addr.GetOffset(), resolve_scope);
    uint32_t resolved = 0;
    if (resolve_scope &
        (eSymbolContextCompUnit | eSymbolContextFunction | eSymbolContextBlock |
         eSymbolContextLineEntry | eSymbolContextVariable)) {
      lldb::addr_t file_vm_addr = so_addr.GetFileAddress();
  
      DWARFDebugInfo *debug_info = DebugInfo();
      if (debug_info) {
        llvm::Expected<DWARFDebugAranges &> aranges =
            debug_info->GetCompileUnitAranges();
        if (!aranges) {
          Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
          LLDB_LOG_ERROR(log, aranges.takeError(),
                         "SymbolFileDWARF::ResolveSymbolContext failed to get cu "
                         "aranges.  {0}");
          return 0;
        }
  
        const dw_offset_t cu_offset = aranges->FindAddress(file_vm_addr);
        if (cu_offset == DW_INVALID_OFFSET) {
          // Global variables are not in the compile unit address ranges. The
          // only way to currently find global variables is to iterate over the
          // .debug_pubnames or the __apple_names table and find all items in
          // there that point to DW_TAG_variable DIEs and then find the address
          // that matches.
          if (resolve_scope & eSymbolContextVariable) {
            GlobalVariableMap &map = GetGlobalAranges();
            const GlobalVariableMap::Entry *entry =
                map.FindEntryThatContains(file_vm_addr);
            if (entry && entry->data) {
              Variable *variable = entry->data;
              SymbolContextScope *scc = variable->GetSymbolContextScope();
              if (scc) {
                scc->CalculateSymbolContext(&sc);
                sc.variable = variable;
              }
              return sc.GetResolvedMask();
            }
          }
        } else {
          uint32_t cu_idx = DW_INVALID_INDEX;
          if (auto *dwarf_cu = llvm::dyn_cast_or_null<DWARFCompileUnit>(
                  debug_info->GetUnitAtOffset(DIERef::Section::DebugInfo,
                                              cu_offset, &cu_idx))) {
            sc.comp_unit = GetCompUnitForDWARFCompUnit(*dwarf_cu);
            if (sc.comp_unit) {
              resolved |= eSymbolContextCompUnit;
  
              bool force_check_line_table = false;
              if (resolve_scope &
                  (eSymbolContextFunction | eSymbolContextBlock)) {
                DWARFDIE function_die = dwarf_cu->LookupAddress(file_vm_addr);
                DWARFDIE block_die;
                if (function_die) {
                  sc.function =
                      sc.comp_unit->FindFunctionByUID(function_die.GetID()).get();
                  if (sc.function == nullptr)
                    sc.function = ParseFunction(*sc.comp_unit, function_die);
  
                  if (sc.function && (resolve_scope & eSymbolContextBlock))
                    block_die = function_die.LookupDeepestBlock(file_vm_addr);
                } else {
                  // We might have had a compile unit that had discontiguous
                  // address ranges where the gaps are symbols that don't have
                  // any debug info. Discontiguous compile unit address ranges
                  // should only happen when there aren't other functions from
                  // other compile units in these gaps. This helps keep the size
                  // of the aranges down.
                  force_check_line_table = true;
                }
  
                if (sc.function != nullptr) {
                  resolved |= eSymbolContextFunction;
  
                  if (resolve_scope & eSymbolContextBlock) {
                    Block &block = sc.function->GetBlock(true);
  
                    if (block_die)
                      sc.block = block.FindBlockByID(block_die.GetID());
                    else
                      sc.block = block.FindBlockByID(function_die.GetID());
                    if (sc.block)
                      resolved |= eSymbolContextBlock;
                  }
                }
              }
  
              if ((resolve_scope & eSymbolContextLineEntry) ||
                  force_check_line_table) {
                LineTable *line_table = sc.comp_unit->GetLineTable();
                if (line_table != nullptr) {
                  // And address that makes it into this function should be in
                  // terms of this debug file if there is no debug map, or it
                  // will be an address in the .o file which needs to be fixed up
                  // to be in terms of the debug map executable. Either way,
                  // calling FixupAddress() will work for us.
                  Address exe_so_addr(so_addr);
                  if (FixupAddress(exe_so_addr)) {
                    if (line_table->FindLineEntryByAddress(exe_so_addr,
                                                           sc.line_entry)) {
                      resolved |= eSymbolContextLineEntry;
                    }
                  }
                }
              }
  
              if (force_check_line_table &&
                  !(resolved & eSymbolContextLineEntry)) {
                // We might have had a compile unit that had discontiguous
                // address ranges where the gaps are symbols that don't have any
                // debug info. Discontiguous compile unit address ranges should
                // only happen when there aren't other functions from other
                // compile units in these gaps. This helps keep the size of the
                // aranges down.
                sc.comp_unit = nullptr;
                resolved &= ~eSymbolContextCompUnit;
              }
            } else {
              GetObjectFile()->GetModule()->ReportWarning(
                  "0x%8.8x: compile unit %u failed to create a valid "
                  "lldb_private::CompileUnit class.",
                  cu_offset, cu_idx);
            }
          }
        }
      }
    }
    return resolved;
  }
  
  uint32_t SymbolFileDWARF::ResolveSymbolContext(const FileSpec &file_spec,
                                                 uint32_t line,
                                                 bool check_inlines,
                                                 SymbolContextItem resolve_scope,
                                                 SymbolContextList &sc_list) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    const uint32_t prev_size = sc_list.GetSize();
    if (resolve_scope & eSymbolContextCompUnit) {
      for (uint32_t cu_idx = 0, num_cus = GetNumCompileUnits(); cu_idx < num_cus;
           ++cu_idx) {
        CompileUnit *dc_cu = ParseCompileUnitAtIndex(cu_idx).get();
        if (!dc_cu)
          continue;
  
        bool file_spec_matches_cu_file_spec =
            FileSpec::Match(file_spec, dc_cu->GetPrimaryFile());
        if (check_inlines || file_spec_matches_cu_file_spec) {
          SymbolContext sc(m_objfile_sp->GetModule());
          sc.comp_unit = dc_cu;
          uint32_t file_idx = UINT32_MAX;
  
          // If we are looking for inline functions only and we don't find it
          // in the support files, we are done.
          if (check_inlines) {
            file_idx =
                sc.comp_unit->GetSupportFiles().FindFileIndex(1, file_spec, true);
            if (file_idx == UINT32_MAX)
              continue;
          }
  
          if (line != 0) {
            LineTable *line_table = sc.comp_unit->GetLineTable();
  
            if (line_table != nullptr && line != 0) {
              // We will have already looked up the file index if we are
              // searching for inline entries.
              if (!check_inlines)
                file_idx = sc.comp_unit->GetSupportFiles().FindFileIndex(
                    1, file_spec, true);
  
              if (file_idx != UINT32_MAX) {
                uint32_t found_line;
                uint32_t line_idx = line_table->FindLineEntryIndexByFileIndex(
                    0, file_idx, line, false, &sc.line_entry);
                found_line = sc.line_entry.line;
  
                while (line_idx != UINT32_MAX) {
                  sc.function = nullptr;
                  sc.block = nullptr;
                  if (resolve_scope &
                      (eSymbolContextFunction | eSymbolContextBlock)) {
                    const lldb::addr_t file_vm_addr =
                        sc.line_entry.range.GetBaseAddress().GetFileAddress();
                    if (file_vm_addr != LLDB_INVALID_ADDRESS) {
                      DWARFDIE function_die =
                          GetDWARFCompileUnit(dc_cu)->LookupAddress(file_vm_addr);
                      DWARFDIE block_die;
                      if (function_die) {
                        sc.function =
                            sc.comp_unit->FindFunctionByUID(function_die.GetID())
                                .get();
                        if (sc.function == nullptr)
                          sc.function =
                              ParseFunction(*sc.comp_unit, function_die);
  
                        if (sc.function && (resolve_scope & eSymbolContextBlock))
                          block_die =
                              function_die.LookupDeepestBlock(file_vm_addr);
                      }
  
                      if (sc.function != nullptr) {
                        Block &block = sc.function->GetBlock(true);
  
                        if (block_die)
                          sc.block = block.FindBlockByID(block_die.GetID());
                        else if (function_die)
                          sc.block = block.FindBlockByID(function_die.GetID());
                      }
                    }
                  }
  
                  sc_list.Append(sc);
                  line_idx = line_table->FindLineEntryIndexByFileIndex(
                      line_idx + 1, file_idx, found_line, true, &sc.line_entry);
                }
              }
            } else if (file_spec_matches_cu_file_spec && !check_inlines) {
              // only append the context if we aren't looking for inline call
              // sites by file and line and if the file spec matches that of
              // the compile unit
              sc_list.Append(sc);
            }
          } else if (file_spec_matches_cu_file_spec && !check_inlines) {
            // only append the context if we aren't looking for inline call
            // sites by file and line and if the file spec matches that of
            // the compile unit
            sc_list.Append(sc);
          }
  
          if (!check_inlines)
            break;
        }
      }
    }
    return sc_list.GetSize() - prev_size;
  }
  
  void SymbolFileDWARF::PreloadSymbols() {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    m_index->Preload();
  }
  
  std::recursive_mutex &SymbolFileDWARF::GetModuleMutex() const {
    lldb::ModuleSP module_sp(m_debug_map_module_wp.lock());
    if (module_sp)
      return module_sp->GetMutex();
    return GetObjectFile()->GetModule()->GetMutex();
  }
  
  bool SymbolFileDWARF::DeclContextMatchesThisSymbolFile(
      const lldb_private::CompilerDeclContext *decl_ctx) {
    if (decl_ctx == nullptr || !decl_ctx->IsValid()) {
      // Invalid namespace decl which means we aren't matching only things in
      // this symbol file, so return true to indicate it matches this symbol
      // file.
      return true;
    }
  
    TypeSystem *decl_ctx_type_system = decl_ctx->GetTypeSystem();
    auto type_system_or_err = GetTypeSystemForLanguage(
        decl_ctx_type_system->GetMinimumLanguage(nullptr));
    if (auto err = type_system_or_err.takeError()) {
      LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
                     std::move(err),
                     "Unable to match namespace decl using TypeSystem");
      return false;
    }
  
    if (decl_ctx_type_system == &type_system_or_err.get())
      return true; // The type systems match, return true
  
    // The namespace AST was valid, and it does not match...
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
  
    if (log)
      GetObjectFile()->GetModule()->LogMessage(
          log, "Valid namespace does not match symbol file");
  
    return false;
  }
  
  void SymbolFileDWARF::FindGlobalVariables(
      ConstString name, const CompilerDeclContext *parent_decl_ctx,
      uint32_t max_matches, VariableList &variables) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
  
    if (log)
      GetObjectFile()->GetModule()->LogMessage(
          log,
          "SymbolFileDWARF::FindGlobalVariables (name=\"%s\", "
          "parent_decl_ctx=%p, max_matches=%u, variables)",
          name.GetCString(), static_cast<const void *>(parent_decl_ctx),
          max_matches);
  
    if (!DeclContextMatchesThisSymbolFile(parent_decl_ctx))
      return;
  
    DWARFDebugInfo *info = DebugInfo();
    if (!info)
      return;
  
    // Remember how many variables are in the list before we search.
    const uint32_t original_size = variables.GetSize();
  
    llvm::StringRef basename;
    llvm::StringRef context;
    bool name_is_mangled = (bool)Mangled(name);
  
    if (!CPlusPlusLanguage::ExtractContextAndIdentifier(name.GetCString(),
                                                        context, basename))
      basename = name.GetStringRef();
  
    DIEArray die_offsets;
    m_index->GetGlobalVariables(ConstString(basename), die_offsets);
    const size_t num_die_matches = die_offsets.size();
    if (num_die_matches) {
      SymbolContext sc;
      sc.module_sp = m_objfile_sp->GetModule();
      assert(sc.module_sp);
  
      // Loop invariant: Variables up to this index have been checked for context
      // matches.
      uint32_t pruned_idx = original_size;
  
      bool done = false;
      for (size_t i = 0; i < num_die_matches && !done; ++i) {
        const DIERef &die_ref = die_offsets[i];
        DWARFDIE die = GetDIE(die_ref);
  
        if (die) {
          switch (die.Tag()) {
          default:
          case DW_TAG_subprogram:
          case DW_TAG_inlined_subroutine:
          case DW_TAG_try_block:
          case DW_TAG_catch_block:
            break;
  
          case DW_TAG_variable: {
            auto *dwarf_cu = llvm::dyn_cast<DWARFCompileUnit>(die.GetCU());
            if (!dwarf_cu)
              continue;
            sc.comp_unit = GetCompUnitForDWARFCompUnit(*dwarf_cu);
  
            if (parent_decl_ctx) {
              DWARFASTParser *dwarf_ast = die.GetDWARFParser();
              if (dwarf_ast) {
                CompilerDeclContext actual_parent_decl_ctx =
                    dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
                if (!actual_parent_decl_ctx ||
                    actual_parent_decl_ctx != *parent_decl_ctx)
                  continue;
              }
            }
  
            ParseVariables(sc, die, LLDB_INVALID_ADDRESS, false, false,
                           &variables);
            while (pruned_idx < variables.GetSize()) {
              VariableSP var_sp = variables.GetVariableAtIndex(pruned_idx);
              if (name_is_mangled ||
                  var_sp->GetName().GetStringRef().contains(name.GetStringRef()))
                ++pruned_idx;
              else
                variables.RemoveVariableAtIndex(pruned_idx);
            }
  
            if (variables.GetSize() - original_size >= max_matches)
              done = true;
          } break;
          }
        } else {
          m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
        }
      }
    }
  
    // Return the number of variable that were appended to the list
    const uint32_t num_matches = variables.GetSize() - original_size;
    if (log && num_matches > 0) {
      GetObjectFile()->GetModule()->LogMessage(
          log,
          "SymbolFileDWARF::FindGlobalVariables (name=\"%s\", "
          "parent_decl_ctx=%p, max_matches=%u, variables) => %u",
          name.GetCString(), static_cast<const void *>(parent_decl_ctx),
          max_matches, num_matches);
    }
  }
  
  void SymbolFileDWARF::FindGlobalVariables(const RegularExpression &regex,
                                            uint32_t max_matches,
                                            VariableList &variables) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
  
    if (log) {
      GetObjectFile()->GetModule()->LogMessage(
          log,
          "SymbolFileDWARF::FindGlobalVariables (regex=\"%s\", "
          "max_matches=%u, variables)",
          regex.GetText().str().c_str(), max_matches);
    }
  
    DWARFDebugInfo *info = DebugInfo();
    if (!info)
      return;
  
    // Remember how many variables are in the list before we search.
    const uint32_t original_size = variables.GetSize();
  
    DIEArray die_offsets;
    m_index->GetGlobalVariables(regex, die_offsets);
  
    SymbolContext sc;
    sc.module_sp = m_objfile_sp->GetModule();
    assert(sc.module_sp);
  
    const size_t num_matches = die_offsets.size();
    if (num_matches) {
      for (size_t i = 0; i < num_matches; ++i) {
        const DIERef &die_ref = die_offsets[i];
        DWARFDIE die = GetDIE(die_ref);
  
        if (die) {
          DWARFCompileUnit *dwarf_cu =
              llvm::dyn_cast<DWARFCompileUnit>(die.GetCU());
          if (!dwarf_cu)
            continue;
          sc.comp_unit = GetCompUnitForDWARFCompUnit(*dwarf_cu);
  
          ParseVariables(sc, die, LLDB_INVALID_ADDRESS, false, false, &variables);
  
          if (variables.GetSize() - original_size >= max_matches)
            break;
        } else
          m_index->ReportInvalidDIERef(die_ref, regex.GetText());
      }
    }
  }
  
  bool SymbolFileDWARF::ResolveFunction(const DWARFDIE &orig_die,
                                        bool include_inlines,
                                        SymbolContextList &sc_list) {
    SymbolContext sc;
  
    if (!orig_die)
      return false;
  
    // If we were passed a die that is not a function, just return false...
    if (!(orig_die.Tag() == DW_TAG_subprogram ||
          (include_inlines && orig_die.Tag() == DW_TAG_inlined_subroutine)))
      return false;
  
    DWARFDIE die = orig_die;
    DWARFDIE inlined_die;
    if (die.Tag() == DW_TAG_inlined_subroutine) {
      inlined_die = die;
  
      while (true) {
        die = die.GetParent();
  
        if (die) {
          if (die.Tag() == DW_TAG_subprogram)
            break;
        } else
          break;
      }
    }
    assert(die && die.Tag() == DW_TAG_subprogram);
    if (GetFunction(die, sc)) {
      Address addr;
      // Parse all blocks if needed
      if (inlined_die) {
        Block &function_block = sc.function->GetBlock(true);
        sc.block = function_block.FindBlockByID(inlined_die.GetID());
        if (sc.block == nullptr)
          sc.block = function_block.FindBlockByID(inlined_die.GetOffset());
        if (sc.block == nullptr || !sc.block->GetStartAddress(addr))
          addr.Clear();
      } else {
        sc.block = nullptr;
        addr = sc.function->GetAddressRange().GetBaseAddress();
      }
  
  
      if (auto section_sp = addr.GetSection()) {
        if (section_sp->GetPermissions() & ePermissionsExecutable) {
          sc_list.Append(sc);
          return true;
        }
      }
    }
  
    return false;
  }
  
  bool SymbolFileDWARF::DIEInDeclContext(const CompilerDeclContext *decl_ctx,
                                         const DWARFDIE &die) {
    // If we have no parent decl context to match this DIE matches, and if the
    // parent decl context isn't valid, we aren't trying to look for any
    // particular decl context so any die matches.
    if (decl_ctx == nullptr || !decl_ctx->IsValid())
      return true;
  
    if (die) {
      DWARFASTParser *dwarf_ast = die.GetDWARFParser();
      if (dwarf_ast) {
        CompilerDeclContext actual_decl_ctx =
            dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
        if (actual_decl_ctx)
          return decl_ctx->IsContainedInLookup(actual_decl_ctx);
      }
    }
    return false;
  }
  
  void SymbolFileDWARF::FindFunctions(ConstString name,
                                      const CompilerDeclContext *parent_decl_ctx,
                                      FunctionNameType name_type_mask,
                                      bool include_inlines,
                                      SymbolContextList &sc_list) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
    Timer scoped_timer(func_cat, "SymbolFileDWARF::FindFunctions (name = '%s')",
                       name.AsCString());
  
    // eFunctionNameTypeAuto should be pre-resolved by a call to
    // Module::LookupInfo::LookupInfo()
    assert((name_type_mask & eFunctionNameTypeAuto) == 0);
  
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
  
    if (log) {
      GetObjectFile()->GetModule()->LogMessage(
          log,
          "SymbolFileDWARF::FindFunctions (name=\"%s\", name_type_mask=0x%x, sc_list)",
          name.GetCString(), name_type_mask);
    }
  
    if (!DeclContextMatchesThisSymbolFile(parent_decl_ctx))
      return;
  
    // If name is empty then we won't find anything.
    if (name.IsEmpty())
      return;
  
    // Remember how many sc_list are in the list before we search in case we are
    // appending the results to a variable list.
  
    const uint32_t original_size = sc_list.GetSize();
  
    llvm::DenseSet<const DWARFDebugInfoEntry *> resolved_dies;
    DIEArray offsets;
    CompilerDeclContext empty_decl_ctx;
    if (!parent_decl_ctx)
      parent_decl_ctx = &empty_decl_ctx;
  
    std::vector<DWARFDIE> dies;
    m_index->GetFunctions(name, *this, *parent_decl_ctx, name_type_mask, dies);
    for (const DWARFDIE &die : dies) {
      if (resolved_dies.insert(die.GetDIE()).second)
        ResolveFunction(die, include_inlines, sc_list);
    }
  
    // Return the number of variable that were appended to the list
    const uint32_t num_matches = sc_list.GetSize() - original_size;
  
    if (log && num_matches > 0) {
      GetObjectFile()->GetModule()->LogMessage(
          log,
          "SymbolFileDWARF::FindFunctions (name=\"%s\", "
          "name_type_mask=0x%x, include_inlines=%d, sc_list) => %u",
          name.GetCString(), name_type_mask, include_inlines,
          num_matches);
    }
  }
  
  void SymbolFileDWARF::FindFunctions(const RegularExpression &regex,
                                      bool include_inlines,
                                      SymbolContextList &sc_list) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
    Timer scoped_timer(func_cat, "SymbolFileDWARF::FindFunctions (regex = '%s')",
                       regex.GetText().str().c_str());
  
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
  
    if (log) {
      GetObjectFile()->GetModule()->LogMessage(
          log, "SymbolFileDWARF::FindFunctions (regex=\"%s\", sc_list)",
          regex.GetText().str().c_str());
    }
  
    DWARFDebugInfo *info = DebugInfo();
    if (!info)
      return;
  
    DIEArray offsets;
    m_index->GetFunctions(regex, offsets);
  
    llvm::DenseSet<const DWARFDebugInfoEntry *> resolved_dies;
    for (DIERef ref : offsets) {
      DWARFDIE die = info->GetDIE(ref);
      if (!die) {
        m_index->ReportInvalidDIERef(ref, regex.GetText());
        continue;
      }
      if (resolved_dies.insert(die.GetDIE()).second)
        ResolveFunction(die, include_inlines, sc_list);
    }
  }
  
  void SymbolFileDWARF::GetMangledNamesForFunction(
      const std::string &scope_qualified_name,
      std::vector<ConstString> &mangled_names) {
    DWARFDebugInfo *info = DebugInfo();
    uint32_t num_comp_units = 0;
    if (info)
      num_comp_units = info->GetNumUnits();
  
    for (uint32_t i = 0; i < num_comp_units; i++) {
      DWARFUnit *cu = info->GetUnitAtIndex(i);
      if (cu == nullptr)
        continue;
  
      SymbolFileDWARFDwo *dwo = cu->GetDwoSymbolFile();
      if (dwo)
        dwo->GetMangledNamesForFunction(scope_qualified_name, mangled_names);
    }
  
    for (lldb::user_id_t uid :
         m_function_scope_qualified_name_map.lookup(scope_qualified_name)) {
      DWARFDIE die = GetDIE(uid);
      mangled_names.push_back(ConstString(die.GetMangledName()));
    }
  }
  
  void SymbolFileDWARF::FindTypes(
      ConstString name, const CompilerDeclContext *parent_decl_ctx,
      uint32_t max_matches,
      llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
      TypeMap &types) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    // Make sure we haven't already searched this SymbolFile before.
    if (!searched_symbol_files.insert(this).second)
      return;
  
    DWARFDebugInfo *info = DebugInfo();
    if (!info)
      return;
  
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
  
    if (log) {
      if (parent_decl_ctx)
        GetObjectFile()->GetModule()->LogMessage(
            log,
            "SymbolFileDWARF::FindTypes (sc, name=\"%s\", parent_decl_ctx = "
            "%p (\"%s\"), max_matches=%u, type_list)",
            name.GetCString(), static_cast<const void *>(parent_decl_ctx),
            parent_decl_ctx->GetName().AsCString("<NULL>"), max_matches);
      else
        GetObjectFile()->GetModule()->LogMessage(
            log,
            "SymbolFileDWARF::FindTypes (sc, name=\"%s\", parent_decl_ctx = "
            "NULL, max_matches=%u, type_list)",
            name.GetCString(), max_matches);
    }
  
    if (!DeclContextMatchesThisSymbolFile(parent_decl_ctx))
      return;
  
    DIEArray die_offsets;
    m_index->GetTypes(name, die_offsets);
    const size_t num_die_matches = die_offsets.size();
  
    for (size_t i = 0; i < num_die_matches; ++i) {
      const DIERef &die_ref = die_offsets[i];
      DWARFDIE die = GetDIE(die_ref);
      if (die) {
        if (!DIEInDeclContext(parent_decl_ctx, die))
          continue; // The containing decl contexts don't match
  
        Type *matching_type = ResolveType(die, true, true);
        if (matching_type) {
          // We found a type pointer, now find the shared pointer form our type
          // list
          types.InsertUnique(matching_type->shared_from_this());
          if (types.GetSize() >= max_matches)
            break;
        }
      } else {
        m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
      }
    }
  
    // Next search through the reachable Clang modules. This only applies for
    // DWARF objects compiled with -gmodules that haven't been processed by
    // dsymutil.
    if (num_die_matches < max_matches) {
      UpdateExternalModuleListIfNeeded();
  
      for (const auto &pair : m_external_type_modules)
        if (ModuleSP external_module_sp = pair.second) 
          if (SymbolFile *sym_file = external_module_sp->GetSymbolFile())
            sym_file->FindTypes(name, parent_decl_ctx, max_matches,
                                searched_symbol_files, types);
    }
  
    if (log && types.GetSize()) {
      if (parent_decl_ctx) {
        GetObjectFile()->GetModule()->LogMessage(
            log,
            "SymbolFileDWARF::FindTypes (sc, name=\"%s\", parent_decl_ctx "
            "= %p (\"%s\"), max_matches=%u, type_list) => %u",
            name.GetCString(), static_cast<const void *>(parent_decl_ctx),
            parent_decl_ctx->GetName().AsCString("<NULL>"), max_matches,
            types.GetSize());
      } else {
        GetObjectFile()->GetModule()->LogMessage(
            log,
            "SymbolFileDWARF::FindTypes (sc, name=\"%s\", parent_decl_ctx "
            "= NULL, max_matches=%u, type_list) => %u",
            name.GetCString(), max_matches, types.GetSize());
      }
    }
  }
  
  void SymbolFileDWARF::FindTypes(
      llvm::ArrayRef<CompilerContext> pattern, LanguageSet languages,
      llvm::DenseSet<SymbolFile *> &searched_symbol_files, TypeMap &types) {
    // Make sure we haven't already searched this SymbolFile before.
    if (!searched_symbol_files.insert(this).second)
      return;
  
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    if (pattern.empty())
      return;
  
    ConstString name = pattern.back().name;
  
    if (!name)
      return;
  
    DIEArray die_offsets;
    m_index->GetTypes(name, die_offsets);
    const size_t num_die_matches = die_offsets.size();
  
    for (size_t i = 0; i < num_die_matches; ++i) {
      const DIERef &die_ref = die_offsets[i];
      DWARFDIE die = GetDIE(die_ref);
  
      if (!die) {
        m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
        continue;
      }
      if (!languages[die.GetCU()->GetLanguageType()])
        continue;
  
      llvm::SmallVector<CompilerContext, 4> die_context;
      die.GetDeclContext(die_context);
      if (!contextMatches(die_context, pattern))
        continue;
  
      if (Type *matching_type = ResolveType(die, true, true)) {
        // We found a type pointer, now find the shared pointer form our type
        // list.
        types.InsertUnique(matching_type->shared_from_this());
      }
    }
  
    // Next search through the reachable Clang modules. This only applies for
    // DWARF objects compiled with -gmodules that haven't been processed by
    // dsymutil.
    UpdateExternalModuleListIfNeeded();
  
    for (const auto &pair : m_external_type_modules)
      if (ModuleSP external_module_sp = pair.second)
        external_module_sp->FindTypes(pattern, languages, searched_symbol_files,
                                      types);
  }
  
  CompilerDeclContext
  SymbolFileDWARF::FindNamespace(ConstString name,
                                 const CompilerDeclContext *parent_decl_ctx) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
  
    if (log) {
      GetObjectFile()->GetModule()->LogMessage(
          log, "SymbolFileDWARF::FindNamespace (sc, name=\"%s\")",
          name.GetCString());
    }
  
    CompilerDeclContext namespace_decl_ctx;
  
    if (!DeclContextMatchesThisSymbolFile(parent_decl_ctx))
      return namespace_decl_ctx;
  
    DWARFDebugInfo *info = DebugInfo();
    if (info) {
      DIEArray die_offsets;
      m_index->GetNamespaces(name, die_offsets);
      const size_t num_matches = die_offsets.size();
      if (num_matches) {
        for (size_t i = 0; i < num_matches; ++i) {
          const DIERef &die_ref = die_offsets[i];
          DWARFDIE die = GetDIE(die_ref);
  
          if (die) {
            if (!DIEInDeclContext(parent_decl_ctx, die))
              continue; // The containing decl contexts don't match
  
            DWARFASTParser *dwarf_ast = die.GetDWARFParser();
            if (dwarf_ast) {
              namespace_decl_ctx = dwarf_ast->GetDeclContextForUIDFromDWARF(die);
              if (namespace_decl_ctx)
                break;
            }
          } else {
            m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
          }
        }
      }
    }
    if (log && namespace_decl_ctx) {
      GetObjectFile()->GetModule()->LogMessage(
          log,
          "SymbolFileDWARF::FindNamespace (sc, name=\"%s\") => "
          "CompilerDeclContext(%p/%p) \"%s\"",
          name.GetCString(),
          static_cast<const void *>(namespace_decl_ctx.GetTypeSystem()),
          static_cast<const void *>(namespace_decl_ctx.GetOpaqueDeclContext()),
          namespace_decl_ctx.GetName().AsCString("<NULL>"));
    }
  
    return namespace_decl_ctx;
  }
  
  TypeSP SymbolFileDWARF::GetTypeForDIE(const DWARFDIE &die,
                                        bool resolve_function_context) {
    TypeSP type_sp;
    if (die) {
      Type *type_ptr = GetDIEToType().lookup(die.GetDIE());
      if (type_ptr == nullptr) {
        SymbolContextScope *scope;
        if (auto *dwarf_cu = llvm::dyn_cast<DWARFCompileUnit>(die.GetCU()))
          scope = GetCompUnitForDWARFCompUnit(*dwarf_cu);
        else
          scope = GetObjectFile()->GetModule().get();
        assert(scope);
        SymbolContext sc(scope);
        const DWARFDebugInfoEntry *parent_die = die.GetParent().GetDIE();
        while (parent_die != nullptr) {
          if (parent_die->Tag() == DW_TAG_subprogram)
            break;
          parent_die = parent_die->GetParent();
        }
        SymbolContext sc_backup = sc;
        if (resolve_function_context && parent_die != nullptr &&
            !GetFunction(DWARFDIE(die.GetCU(), parent_die), sc))
          sc = sc_backup;
  
        type_sp = ParseType(sc, die, nullptr);
      } else if (type_ptr != DIE_IS_BEING_PARSED) {
        // Grab the existing type from the master types lists
        type_sp = type_ptr->shared_from_this();
      }
    }
    return type_sp;
  }
  
  DWARFDIE
  SymbolFileDWARF::GetDeclContextDIEContainingDIE(const DWARFDIE &orig_die) {
    if (orig_die) {
      DWARFDIE die = orig_die;
  
      while (die) {
        // If this is the original DIE that we are searching for a declaration
        // for, then don't look in the cache as we don't want our own decl
        // context to be our decl context...
        if (orig_die != die) {
          switch (die.Tag()) {
          case DW_TAG_compile_unit:
          case DW_TAG_partial_unit:
          case DW_TAG_namespace:
          case DW_TAG_structure_type:
          case DW_TAG_union_type:
          case DW_TAG_class_type:
          case DW_TAG_lexical_block:
          case DW_TAG_subprogram:
            return die;
          case DW_TAG_inlined_subroutine: {
            DWARFDIE abs_die = die.GetReferencedDIE(DW_AT_abstract_origin);
            if (abs_die) {
              return abs_die;
            }
            break;
          }
          default:
            break;
          }
        }
  
        DWARFDIE spec_die = die.GetReferencedDIE(DW_AT_specification);
        if (spec_die) {
          DWARFDIE decl_ctx_die = GetDeclContextDIEContainingDIE(spec_die);
          if (decl_ctx_die)
            return decl_ctx_die;
        }
  
        DWARFDIE abs_die = die.GetReferencedDIE(DW_AT_abstract_origin);
        if (abs_die) {
          DWARFDIE decl_ctx_die = GetDeclContextDIEContainingDIE(abs_die);
          if (decl_ctx_die)
            return decl_ctx_die;
        }
  
        die = die.GetParent();
      }
    }
    return DWARFDIE();
  }
  
  Symbol *SymbolFileDWARF::GetObjCClassSymbol(ConstString objc_class_name) {
    Symbol *objc_class_symbol = nullptr;
    if (m_objfile_sp) {
      Symtab *symtab = m_objfile_sp->GetSymtab();
      if (symtab) {
        objc_class_symbol = symtab->FindFirstSymbolWithNameAndType(
            objc_class_name, eSymbolTypeObjCClass, Symtab::eDebugNo,
            Symtab::eVisibilityAny);
      }
    }
    return objc_class_symbol;
  }
  
  // Some compilers don't emit the DW_AT_APPLE_objc_complete_type attribute. If
  // they don't then we can end up looking through all class types for a complete
  // type and never find the full definition. We need to know if this attribute
  // is supported, so we determine this here and cache th result. We also need to
  // worry about the debug map
  // DWARF file
  // if we are doing darwin DWARF in .o file debugging.
  bool SymbolFileDWARF::Supports_DW_AT_APPLE_objc_complete_type(DWARFUnit *cu) {
    if (m_supports_DW_AT_APPLE_objc_complete_type == eLazyBoolCalculate) {
      m_supports_DW_AT_APPLE_objc_complete_type = eLazyBoolNo;
      if (cu && cu->Supports_DW_AT_APPLE_objc_complete_type())
        m_supports_DW_AT_APPLE_objc_complete_type = eLazyBoolYes;
      else {
        DWARFDebugInfo *debug_info = DebugInfo();
        const uint32_t num_compile_units = GetNumCompileUnits();
        for (uint32_t cu_idx = 0; cu_idx < num_compile_units; ++cu_idx) {
          DWARFUnit *dwarf_cu = debug_info->GetUnitAtIndex(cu_idx);
          if (dwarf_cu != cu &&
              dwarf_cu->Supports_DW_AT_APPLE_objc_complete_type()) {
            m_supports_DW_AT_APPLE_objc_complete_type = eLazyBoolYes;
            break;
          }
        }
      }
      if (m_supports_DW_AT_APPLE_objc_complete_type == eLazyBoolNo &&
          GetDebugMapSymfile())
        return m_debug_map_symfile->Supports_DW_AT_APPLE_objc_complete_type(this);
    }
    return m_supports_DW_AT_APPLE_objc_complete_type == eLazyBoolYes;
  }
  
  // This function can be used when a DIE is found that is a forward declaration
  // DIE and we want to try and find a type that has the complete definition.
  TypeSP SymbolFileDWARF::FindCompleteObjCDefinitionTypeForDIE(
      const DWARFDIE &die, ConstString type_name, bool must_be_implementation) {
  
    TypeSP type_sp;
  
    if (!type_name || (must_be_implementation && !GetObjCClassSymbol(type_name)))
      return type_sp;
  
    DIEArray die_offsets;
    m_index->GetCompleteObjCClass(type_name, must_be_implementation, die_offsets);
  
    const size_t num_matches = die_offsets.size();
  
    if (num_matches) {
      for (size_t i = 0; i < num_matches; ++i) {
        const DIERef &die_ref = die_offsets[i];
        DWARFDIE type_die = GetDIE(die_ref);
  
        if (type_die) {
          bool try_resolving_type = false;
  
          // Don't try and resolve the DIE we are looking for with the DIE
          // itself!
          if (type_die != die) {
            switch (type_die.Tag()) {
            case DW_TAG_class_type:
            case DW_TAG_structure_type:
              try_resolving_type = true;
              break;
            default:
              break;
            }
          }
  
          if (try_resolving_type) {
            if (must_be_implementation &&
                type_die.Supports_DW_AT_APPLE_objc_complete_type())
              try_resolving_type = type_die.GetAttributeValueAsUnsigned(
                  DW_AT_APPLE_objc_complete_type, 0);
  
            if (try_resolving_type) {
              Type *resolved_type = ResolveType(type_die, false, true);
              if (resolved_type && resolved_type != DIE_IS_BEING_PARSED) {
                DEBUG_PRINTF("resolved 0x%8.8" PRIx64 " from %s to 0x%8.8" PRIx64
                             " (cu 0x%8.8" PRIx64 ")\n",
                             die.GetID(),
                             m_objfile_sp->GetFileSpec().GetFilename().AsCString(
                                 "<Unknown>"),
                             type_die.GetID(), type_cu->GetID());
  
                if (die)
                  GetDIEToType()[die.GetDIE()] = resolved_type;
                type_sp = resolved_type->shared_from_this();
                break;
              }
            }
          }
        } else {
          m_index->ReportInvalidDIERef(die_ref, type_name.GetStringRef());
        }
      }
    }
    return type_sp;
  }
  
  // This function helps to ensure that the declaration contexts match for two
  // different DIEs. Often times debug information will refer to a forward
  // declaration of a type (the equivalent of "struct my_struct;". There will
  // often be a declaration of that type elsewhere that has the full definition.
  // When we go looking for the full type "my_struct", we will find one or more
  // matches in the accelerator tables and we will then need to make sure the
  // type was in the same declaration context as the original DIE. This function
  // can efficiently compare two DIEs and will return true when the declaration
  // context matches, and false when they don't.
  bool SymbolFileDWARF::DIEDeclContextsMatch(const DWARFDIE &die1,
                                             const DWARFDIE &die2) {
    if (die1 == die2)
      return true;
  
    std::vector<DWARFDIE> decl_ctx_1;
    std::vector<DWARFDIE> decl_ctx_2;
    // The declaration DIE stack is a stack of the declaration context DIEs all
    // the way back to the compile unit. If a type "T" is declared inside a class
    // "B", and class "B" is declared inside a class "A" and class "A" is in a
    // namespace "lldb", and the namespace is in a compile unit, there will be a
    // stack of DIEs:
    //
    //   [0] DW_TAG_class_type for "B"
    //   [1] DW_TAG_class_type for "A"
    //   [2] DW_TAG_namespace  for "lldb"
    //   [3] DW_TAG_compile_unit or DW_TAG_partial_unit for the source file.
    //
    // We grab both contexts and make sure that everything matches all the way
    // back to the compiler unit.
  
    // First lets grab the decl contexts for both DIEs
    decl_ctx_1 = die1.GetDeclContextDIEs();
    decl_ctx_2 = die2.GetDeclContextDIEs();
    // Make sure the context arrays have the same size, otherwise we are done
    const size_t count1 = decl_ctx_1.size();
    const size_t count2 = decl_ctx_2.size();
    if (count1 != count2)
      return false;
  
    // Make sure the DW_TAG values match all the way back up the compile unit. If
    // they don't, then we are done.
    DWARFDIE decl_ctx_die1;
    DWARFDIE decl_ctx_die2;
    size_t i;
    for (i = 0; i < count1; i++) {
      decl_ctx_die1 = decl_ctx_1[i];
      decl_ctx_die2 = decl_ctx_2[i];
      if (decl_ctx_die1.Tag() != decl_ctx_die2.Tag())
        return false;
    }
  #ifndef NDEBUG
  
    // Make sure the top item in the decl context die array is always
    // DW_TAG_compile_unit or DW_TAG_partial_unit. If it isn't then
    // something went wrong in the DWARFDIE::GetDeclContextDIEs()
    // function.
    dw_tag_t cu_tag = decl_ctx_1[count1 - 1].Tag();
    UNUSED_IF_ASSERT_DISABLED(cu_tag);
    assert(cu_tag == DW_TAG_compile_unit || cu_tag == DW_TAG_partial_unit);
  
  #endif
    // Always skip the compile unit when comparing by only iterating up to "count
    // - 1". Here we compare the names as we go.
    for (i = 0; i < count1 - 1; i++) {
      decl_ctx_die1 = decl_ctx_1[i];
      decl_ctx_die2 = decl_ctx_2[i];
      const char *name1 = decl_ctx_die1.GetName();
      const char *name2 = decl_ctx_die2.GetName();
      // If the string was from a DW_FORM_strp, then the pointer will often be
      // the same!
      if (name1 == name2)
        continue;
  
      // Name pointers are not equal, so only compare the strings if both are not
      // NULL.
      if (name1 && name2) {
        // If the strings don't compare, we are done...
        if (strcmp(name1, name2) != 0)
          return false;
      } else {
        // One name was NULL while the other wasn't
        return false;
      }
    }
    // We made it through all of the checks and the declaration contexts are
    // equal.
    return true;
  }
  
  TypeSP SymbolFileDWARF::FindDefinitionTypeForDWARFDeclContext(
      const DWARFDeclContext &dwarf_decl_ctx) {
    TypeSP type_sp;
  
    const uint32_t dwarf_decl_ctx_count = dwarf_decl_ctx.GetSize();
    if (dwarf_decl_ctx_count > 0) {
      const ConstString type_name(dwarf_decl_ctx[0].name);
      const dw_tag_t tag = dwarf_decl_ctx[0].tag;
  
      if (type_name) {
        Log *log(LogChannelDWARF::GetLogIfAny(DWARF_LOG_TYPE_COMPLETION |
                                              DWARF_LOG_LOOKUPS));
        if (log) {
          GetObjectFile()->GetModule()->LogMessage(
              log,
              "SymbolFileDWARF::FindDefinitionTypeForDWARFDeclContext(tag=%"
              "s, qualified-name='%s')",
              DW_TAG_value_to_name(dwarf_decl_ctx[0].tag),
              dwarf_decl_ctx.GetQualifiedName());
        }
  
        DIEArray die_offsets;
        m_index->GetTypes(dwarf_decl_ctx, die_offsets);
        const size_t num_matches = die_offsets.size();
  
        // Get the type system that we are looking to find a type for. We will
        // use this to ensure any matches we find are in a language that this
        // type system supports
        const LanguageType language = dwarf_decl_ctx.GetLanguage();
        TypeSystem *type_system = nullptr;
        if (language != eLanguageTypeUnknown) {
          auto type_system_or_err = GetTypeSystemForLanguage(language);
          if (auto err = type_system_or_err.takeError()) {
            LLDB_LOG_ERROR(
                lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
                std::move(err), "Cannot get TypeSystem for language {}",
                Language::GetNameForLanguageType(language));
          } else {
            type_system = &type_system_or_err.get();
          }
        }
        if (num_matches) {
          for (size_t i = 0; i < num_matches; ++i) {
            const DIERef &die_ref = die_offsets[i];
            DWARFDIE type_die = GetDIE(die_ref);
  
            if (type_die) {
              // Make sure type_die's langauge matches the type system we are
              // looking for. We don't want to find a "Foo" type from Java if we
              // are looking for a "Foo" type for C, C++, ObjC, or ObjC++.
              if (type_system &&
                  !type_system->SupportsLanguage(type_die.GetLanguage()))
                continue;
              bool try_resolving_type = false;
  
              // Don't try and resolve the DIE we are looking for with the DIE
              // itself!
              const dw_tag_t type_tag = type_die.Tag();
              // Make sure the tags match
              if (type_tag == tag) {
                // The tags match, lets try resolving this type
                try_resolving_type = true;
              } else {
                // The tags don't match, but we need to watch our for a forward
                // declaration for a struct and ("struct foo") ends up being a
                // class ("class foo { ... };") or vice versa.
                switch (type_tag) {
                case DW_TAG_class_type:
                  // We had a "class foo", see if we ended up with a "struct foo
                  // { ... };"
                  try_resolving_type = (tag == DW_TAG_structure_type);
                  break;
                case DW_TAG_structure_type:
                  // We had a "struct foo", see if we ended up with a "class foo
                  // { ... };"
                  try_resolving_type = (tag == DW_TAG_class_type);
                  break;
                default:
                  // Tags don't match, don't event try to resolve using this type
                  // whose name matches....
                  break;
                }
              }
  
              if (try_resolving_type) {
                DWARFDeclContext type_dwarf_decl_ctx;
                type_die.GetDWARFDeclContext(type_dwarf_decl_ctx);
  
                if (log) {
                  GetObjectFile()->GetModule()->LogMessage(
                      log,
                      "SymbolFileDWARF::"
                      "FindDefinitionTypeForDWARFDeclContext(tag=%s, "
                      "qualified-name='%s') trying die=0x%8.8x (%s)",
                      DW_TAG_value_to_name(dwarf_decl_ctx[0].tag),
                      dwarf_decl_ctx.GetQualifiedName(), type_die.GetOffset(),
                      type_dwarf_decl_ctx.GetQualifiedName());
                }
  
                // Make sure the decl contexts match all the way up
                if (dwarf_decl_ctx == type_dwarf_decl_ctx) {
                  Type *resolved_type = ResolveType(type_die, false);
                  if (resolved_type && resolved_type != DIE_IS_BEING_PARSED) {
                    type_sp = resolved_type->shared_from_this();
                    break;
                  }
                }
              } else {
                if (log) {
                  std::string qualified_name;
                  type_die.GetQualifiedName(qualified_name);
                  GetObjectFile()->GetModule()->LogMessage(
                      log,
                      "SymbolFileDWARF::"
                      "FindDefinitionTypeForDWARFDeclContext(tag=%s, "
                      "qualified-name='%s') ignoring die=0x%8.8x (%s)",
                      DW_TAG_value_to_name(dwarf_decl_ctx[0].tag),
                      dwarf_decl_ctx.GetQualifiedName(), type_die.GetOffset(),
                      qualified_name.c_str());
                }
              }
            } else {
              m_index->ReportInvalidDIERef(die_ref, type_name.GetStringRef());
            }
          }
        }
      }
    }
    return type_sp;
  }
  
  TypeSP SymbolFileDWARF::ParseType(const SymbolContext &sc, const DWARFDIE &die,
                                    bool *type_is_new_ptr) {
    if (!die)
      return {};
  
    auto type_system_or_err =
        GetTypeSystemForLanguage(die.GetCU()->GetLanguageType());
    if (auto err = type_system_or_err.takeError()) {
      LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
                     std::move(err), "Unable to parse type");
      return {};
    }
  
    DWARFASTParser *dwarf_ast = type_system_or_err->GetDWARFParser();
    if (!dwarf_ast)
      return {};
  
    TypeSP type_sp = dwarf_ast->ParseTypeFromDWARF(sc, die, type_is_new_ptr);
    if (type_sp) {
      GetTypeList().Insert(type_sp);
  
      if (die.Tag() == DW_TAG_subprogram) {
        std::string scope_qualified_name(GetDeclContextForUID(die.GetID())
                                             .GetScopeQualifiedName()
                                             .AsCString(""));
        if (scope_qualified_name.size()) {
          m_function_scope_qualified_name_map[scope_qualified_name].insert(
              die.GetID());
        }
      }
    }
  
    return type_sp;
  }
  
  size_t SymbolFileDWARF::ParseTypes(const SymbolContext &sc,
                                     const DWARFDIE &orig_die,
                                     bool parse_siblings, bool parse_children) {
    size_t types_added = 0;
    DWARFDIE die = orig_die;
  
    while (die) {
      const dw_tag_t tag = die.Tag();
      bool type_is_new = false;
  
      Tag dwarf_tag = static_cast<Tag>(tag);
  
      // TODO: Currently ParseTypeFromDWARF(...) which is called by ParseType(...)
      // does not handle DW_TAG_subrange_type. It is not clear if this is a bug or
      // not.
      if (isType(dwarf_tag) && tag != DW_TAG_subrange_type)
        ParseType(sc, die, &type_is_new);
  
      if (type_is_new)
        ++types_added;
  
      if (parse_children && die.HasChildren()) {
        if (die.Tag() == DW_TAG_subprogram) {
          SymbolContext child_sc(sc);
          child_sc.function = sc.comp_unit->FindFunctionByUID(die.GetID()).get();
          types_added += ParseTypes(child_sc, die.GetFirstChild(), true, true);
        } else
          types_added += ParseTypes(sc, die.GetFirstChild(), true, true);
      }
  
      if (parse_siblings)
        die = die.GetSibling();
      else
        die.Clear();
    }
    return types_added;
  }
  
  size_t SymbolFileDWARF::ParseBlocksRecursive(Function &func) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    CompileUnit *comp_unit = func.GetCompileUnit();
    lldbassert(comp_unit);
  
    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(comp_unit);
    if (!dwarf_cu)
      return 0;
  
    size_t functions_added = 0;
    const dw_offset_t function_die_offset = func.GetID();
    DWARFDIE function_die = dwarf_cu->GetDIE(function_die_offset);
    if (function_die) {
      ParseBlocksRecursive(*comp_unit, &func.GetBlock(false), function_die,
                           LLDB_INVALID_ADDRESS, 0);
    }
  
    return functions_added;
  }
  
  size_t SymbolFileDWARF::ParseTypes(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    size_t types_added = 0;
    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
    if (dwarf_cu) {
      DWARFDIE dwarf_cu_die = dwarf_cu->DIE();
      if (dwarf_cu_die && dwarf_cu_die.HasChildren()) {
        SymbolContext sc;
        sc.comp_unit = &comp_unit;
        types_added = ParseTypes(sc, dwarf_cu_die.GetFirstChild(), true, true);
      }
    }
  
    return types_added;
  }
  
  size_t SymbolFileDWARF::ParseVariablesForContext(const SymbolContext &sc) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    if (sc.comp_unit != nullptr) {
      DWARFDebugInfo *info = DebugInfo();
      if (info == nullptr)
        return 0;
  
      if (sc.function) {
        DWARFDIE function_die = GetDIE(sc.function->GetID());
  
        const dw_addr_t func_lo_pc = function_die.GetAttributeValueAsAddress(
            DW_AT_low_pc, LLDB_INVALID_ADDRESS);
        if (func_lo_pc != LLDB_INVALID_ADDRESS) {
          const size_t num_variables = ParseVariables(
              sc, function_die.GetFirstChild(), func_lo_pc, true, true);
  
          // Let all blocks know they have parse all their variables
          sc.function->GetBlock(false).SetDidParseVariables(true, true);
          return num_variables;
        }
      } else if (sc.comp_unit) {
        DWARFUnit *dwarf_cu = info->GetUnitAtIndex(sc.comp_unit->GetID());
  
        if (dwarf_cu == nullptr)
          return 0;
  
        uint32_t vars_added = 0;
        VariableListSP variables(sc.comp_unit->GetVariableList(false));
  
        if (variables.get() == nullptr) {
          variables = std::make_shared<VariableList>();
          sc.comp_unit->SetVariableList(variables);
  
          DIEArray die_offsets;
          m_index->GetGlobalVariables(dwarf_cu->GetNonSkeletonUnit(),
                                      die_offsets);
          const size_t num_matches = die_offsets.size();
          if (num_matches) {
            for (size_t i = 0; i < num_matches; ++i) {
              const DIERef &die_ref = die_offsets[i];
              DWARFDIE die = GetDIE(die_ref);
              if (die) {
                VariableSP var_sp(
                    ParseVariableDIE(sc, die, LLDB_INVALID_ADDRESS));
                if (var_sp) {
                  variables->AddVariableIfUnique(var_sp);
                  ++vars_added;
                }
              } else
                m_index->ReportInvalidDIERef(die_ref, "");
            }
          }
        }
        return vars_added;
      }
    }
    return 0;
  }
  
  VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
                                               const DWARFDIE &die,
                                               const lldb::addr_t func_low_pc) {
    if (die.GetDWARF() != this)
      return die.GetDWARF()->ParseVariableDIE(sc, die, func_low_pc);
  
    VariableSP var_sp;
    if (!die)
      return var_sp;
  
    var_sp = GetDIEToVariable()[die.GetDIE()];
    if (var_sp)
      return var_sp; // Already been parsed!
  
    const dw_tag_t tag = die.Tag();
    ModuleSP module = GetObjectFile()->GetModule();
  
    if ((tag == DW_TAG_variable) || (tag == DW_TAG_constant) ||
        (tag == DW_TAG_formal_parameter && sc.function)) {
      DWARFAttributes attributes;
      const size_t num_attributes = die.GetAttributes(attributes);
      DWARFDIE spec_die;
      if (num_attributes > 0) {
        const char *name = nullptr;
        const char *mangled = nullptr;
        Declaration decl;
        uint32_t i;
        DWARFFormValue type_die_form;
        DWARFExpression location;
        bool is_external = false;
        bool is_artificial = false;
        bool location_is_const_value_data = false;
        bool has_explicit_location = false;
        DWARFFormValue const_value;
        Variable::RangeList scope_ranges;
        // AccessType accessibility = eAccessNone;
  
        for (i = 0; i < num_attributes; ++i) {
          dw_attr_t attr = attributes.AttributeAtIndex(i);
          DWARFFormValue form_value;
  
          if (attributes.ExtractFormValueAtIndex(i, form_value)) {
            switch (attr) {
            case DW_AT_decl_file:
              decl.SetFile(sc.comp_unit->GetSupportFiles().GetFileSpecAtIndex(
                  form_value.Unsigned()));
              break;
            case DW_AT_decl_line:
              decl.SetLine(form_value.Unsigned());
              break;
            case DW_AT_decl_column:
              decl.SetColumn(form_value.Unsigned());
              break;
            case DW_AT_name:
              name = form_value.AsCString();
              break;
            case DW_AT_linkage_name:
            case DW_AT_MIPS_linkage_name:
              mangled = form_value.AsCString();
              break;
            case DW_AT_type:
              type_die_form = form_value;
              break;
            case DW_AT_external:
              is_external = form_value.Boolean();
              break;
            case DW_AT_const_value:
              // If we have already found a DW_AT_location attribute, ignore this
              // attribute.
              if (!has_explicit_location) {
                location_is_const_value_data = true;
                // The constant value will be either a block, a data value or a
                // string.
                auto debug_info_data = die.GetData();
                if (DWARFFormValue::IsBlockForm(form_value.Form())) {
                  // Retrieve the value as a block expression.
                  uint32_t block_offset =
                      form_value.BlockData() - debug_info_data.GetDataStart();
                  uint32_t block_length = form_value.Unsigned();
                  location = DWARFExpression(
                      module,
                      DataExtractor(debug_info_data, block_offset, block_length),
                      die.GetCU());
                } else if (DWARFFormValue::IsDataForm(form_value.Form())) {
                  // Retrieve the value as a data expression.
                  uint32_t data_offset = attributes.DIEOffsetAtIndex(i);
                  if (auto data_length = form_value.GetFixedSize())
                    location = DWARFExpression(
                        module,
                        DataExtractor(debug_info_data, data_offset, *data_length),
                        die.GetCU());
                  else {
                    const uint8_t *data_pointer = form_value.BlockData();
                    if (data_pointer) {
                      form_value.Unsigned();
                    } else if (DWARFFormValue::IsDataForm(form_value.Form())) {
                      // we need to get the byte size of the type later after we
                      // create the variable
                      const_value = form_value;
                    }
                  }
                } else {
                  // Retrieve the value as a string expression.
                  if (form_value.Form() == DW_FORM_strp) {
                    uint32_t data_offset = attributes.DIEOffsetAtIndex(i);
                    if (auto data_length = form_value.GetFixedSize())
                      location = DWARFExpression(module,
                                                 DataExtractor(debug_info_data,
                                                               data_offset,
                                                               *data_length),
                                                 die.GetCU());
                  } else {
                    const char *str = form_value.AsCString();
                    uint32_t string_offset =
                        str - (const char *)debug_info_data.GetDataStart();
                    uint32_t string_length = strlen(str) + 1;
                    location = DWARFExpression(module,
                                               DataExtractor(debug_info_data,
                                                             string_offset,
                                                             string_length),
                                               die.GetCU());
                  }
                }
              }
              break;
            case DW_AT_location: {
              location_is_const_value_data = false;
              has_explicit_location = true;
              if (DWARFFormValue::IsBlockForm(form_value.Form())) {
                auto data = die.GetData();
  
                uint32_t block_offset =
                    form_value.BlockData() - data.GetDataStart();
                uint32_t block_length = form_value.Unsigned();
                location = DWARFExpression(
                    module, DataExtractor(data, block_offset, block_length),
                    die.GetCU());
              } else {
                DataExtractor data = die.GetCU()->GetLocationData();
                dw_offset_t offset = form_value.Unsigned();
                if (form_value.Form() == DW_FORM_loclistx)
                  offset = die.GetCU()->GetLoclistOffset(offset).getValueOr(-1);
                if (data.ValidOffset(offset)) {
                  data = DataExtractor(data, offset, data.GetByteSize() - offset);
                  location = DWARFExpression(module, data, die.GetCU());
                  assert(func_low_pc != LLDB_INVALID_ADDRESS);
                  location.SetLocationListAddresses(
                      attributes.CompileUnitAtIndex(i)->GetBaseAddress(),
                      func_low_pc);
                }
              }
            } break;
            case DW_AT_specification:
              spec_die = form_value.Reference();
              break;
            case DW_AT_start_scope:
              // TODO: Implement this.
              break;
            case DW_AT_artificial:
              is_artificial = form_value.Boolean();
              break;
            case DW_AT_accessibility:
              break; // accessibility =
                     // DW_ACCESS_to_AccessType(form_value.Unsigned()); break;
            case DW_AT_declaration:
            case DW_AT_description:
            case DW_AT_endianity:
            case DW_AT_segment:
            case DW_AT_visibility:
            default:
            case DW_AT_abstract_origin:
            case DW_AT_sibling:
              break;
            }
          }
        }
  
        const DWARFDIE parent_context_die = GetDeclContextDIEContainingDIE(die);
        const dw_tag_t parent_tag = die.GetParent().Tag();
        bool is_static_member =
            (parent_tag == DW_TAG_compile_unit ||
             parent_tag == DW_TAG_partial_unit) &&
            (parent_context_die.Tag() == DW_TAG_class_type ||
             parent_context_die.Tag() == DW_TAG_structure_type);
  
        ValueType scope = eValueTypeInvalid;
  
        const DWARFDIE sc_parent_die = GetParentSymbolContextDIE(die);
        SymbolContextScope *symbol_context_scope = nullptr;
  
        bool has_explicit_mangled = mangled != nullptr;
        if (!mangled) {
          // LLDB relies on the mangled name (DW_TAG_linkage_name or
          // DW_AT_MIPS_linkage_name) to generate fully qualified names
          // of global variables with commands like "frame var j". For
          // example, if j were an int variable holding a value 4 and
          // declared in a namespace B which in turn is contained in a
          // namespace A, the command "frame var j" returns
          //   "(int) A::B::j = 4".
          // If the compiler does not emit a linkage name, we should be
          // able to generate a fully qualified name from the
          // declaration context.
          if ((parent_tag == DW_TAG_compile_unit ||
               parent_tag == DW_TAG_partial_unit) &&
              Language::LanguageIsCPlusPlus(die.GetLanguage())) {
            DWARFDeclContext decl_ctx;
  
            die.GetDWARFDeclContext(decl_ctx);
            mangled = decl_ctx.GetQualifiedNameAsConstString().GetCString();
          }
        }
  
        if (tag == DW_TAG_formal_parameter)
          scope = eValueTypeVariableArgument;
        else {
          // DWARF doesn't specify if a DW_TAG_variable is a local, global
          // or static variable, so we have to do a little digging:
          // 1) DW_AT_linkage_name implies static lifetime (but may be missing)
          // 2) An empty DW_AT_location is an (optimized-out) static lifetime var.
          // 3) DW_AT_location containing a DW_OP_addr implies static lifetime.
          // Clang likes to combine small global variables into the same symbol
          // with locations like: DW_OP_addr(0x1000), DW_OP_constu(2), DW_OP_plus
          // so we need to look through the whole expression.
          bool is_static_lifetime =
              has_explicit_mangled ||
              (has_explicit_location && !location.IsValid());
          // Check if the location has a DW_OP_addr with any address value...
          lldb::addr_t location_DW_OP_addr = LLDB_INVALID_ADDRESS;
          if (!location_is_const_value_data) {
            bool op_error = false;
            location_DW_OP_addr = location.GetLocation_DW_OP_addr(0, op_error);
            if (op_error) {
              StreamString strm;
              location.DumpLocationForAddress(&strm, eDescriptionLevelFull, 0, 0,
                                              nullptr);
              GetObjectFile()->GetModule()->ReportError(
                  "0x%8.8x: %s has an invalid location: %s", die.GetOffset(),
                  die.GetTagAsCString(), strm.GetData());
            }
            if (location_DW_OP_addr != LLDB_INVALID_ADDRESS)
              is_static_lifetime = true;
          }
          SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile();
          if (debug_map_symfile)
            // Set the module of the expression to the linked module
            // instead of the oject file so the relocated address can be
            // found there.
            location.SetModule(debug_map_symfile->GetObjectFile()->GetModule());
  
          if (is_static_lifetime) {
            if (is_external)
              scope = eValueTypeVariableGlobal;
            else
              scope = eValueTypeVariableStatic;
  
            if (debug_map_symfile) {
              // When leaving the DWARF in the .o files on darwin, when we have a
              // global variable that wasn't initialized, the .o file might not
              // have allocated a virtual address for the global variable. In
              // this case it will have created a symbol for the global variable
              // that is undefined/data and external and the value will be the
              // byte size of the variable. When we do the address map in
              // SymbolFileDWARFDebugMap we rely on having an address, we need to
              // do some magic here so we can get the correct address for our
              // global variable. The address for all of these entries will be
              // zero, and there will be an undefined symbol in this object file,
              // and the executable will have a matching symbol with a good
              // address. So here we dig up the correct address and replace it in
              // the location for the variable, and set the variable's symbol
              // context scope to be that of the main executable so the file
              // address will resolve correctly.
              bool linked_oso_file_addr = false;
              if (is_external && location_DW_OP_addr == 0) {
                // we have a possible uninitialized extern global
                ConstString const_name(mangled ? mangled : name);
                ObjectFile *debug_map_objfile =
                    debug_map_symfile->GetObjectFile();
                if (debug_map_objfile) {
                  Symtab *debug_map_symtab = debug_map_objfile->GetSymtab();
                  if (debug_map_symtab) {
                    Symbol *exe_symbol =
                        debug_map_symtab->FindFirstSymbolWithNameAndType(
                            const_name, eSymbolTypeData, Symtab::eDebugYes,
                            Symtab::eVisibilityExtern);
                    if (exe_symbol) {
                      if (exe_symbol->ValueIsAddress()) {
                        const addr_t exe_file_addr =
                            exe_symbol->GetAddressRef().GetFileAddress();
                        if (exe_file_addr != LLDB_INVALID_ADDRESS) {
                          if (location.Update_DW_OP_addr(exe_file_addr)) {
                            linked_oso_file_addr = true;
                            symbol_context_scope = exe_symbol;
                          }
                        }
                      }
                    }
                  }
                }
              }
  
              if (!linked_oso_file_addr) {
                // The DW_OP_addr is not zero, but it contains a .o file address
                // which needs to be linked up correctly.
                const lldb::addr_t exe_file_addr =
                    debug_map_symfile->LinkOSOFileAddress(this,
                                                          location_DW_OP_addr);
                if (exe_file_addr != LLDB_INVALID_ADDRESS) {
                  // Update the file address for this variable
                  location.Update_DW_OP_addr(exe_file_addr);
                } else {
                  // Variable didn't make it into the final executable
                  return var_sp;
                }
              }
            }
          } else {
            if (location_is_const_value_data)
              scope = eValueTypeVariableStatic;
            else {
              scope = eValueTypeVariableLocal;
              if (debug_map_symfile) {
                // We need to check for TLS addresses that we need to fixup
                if (location.ContainsThreadLocalStorage()) {
                  location.LinkThreadLocalStorage(
                      debug_map_symfile->GetObjectFile()->GetModule(),
                      [this, debug_map_symfile](
                          lldb::addr_t unlinked_file_addr) -> lldb::addr_t {
                        return debug_map_symfile->LinkOSOFileAddress(
                            this, unlinked_file_addr);
                      });
                  scope = eValueTypeVariableThreadLocal;
                }
              }
            }
          }
        }
  
        if (symbol_context_scope == nullptr) {
          switch (parent_tag) {
          case DW_TAG_subprogram:
          case DW_TAG_inlined_subroutine:
          case DW_TAG_lexical_block:
            if (sc.function) {
              symbol_context_scope = sc.function->GetBlock(true).FindBlockByID(
                  sc_parent_die.GetID());
              if (symbol_context_scope == nullptr)
                symbol_context_scope = sc.function;
            }
            break;
  
          default:
            symbol_context_scope = sc.comp_unit;
            break;
          }
        }
  
        if (symbol_context_scope) {
          SymbolFileTypeSP type_sp(
              new SymbolFileType(*this, GetUID(type_die_form.Reference())));
  
          if (const_value.Form() && type_sp && type_sp->GetType())
            location.UpdateValue(const_value.Unsigned(),
                                 type_sp->GetType()->GetByteSize().getValueOr(0),
                                 die.GetCU()->GetAddressByteSize());
  
          var_sp = std::make_shared<Variable>(
              die.GetID(), name, mangled, type_sp, scope, symbol_context_scope,
              scope_ranges, &decl, location, is_external, is_artificial,
              is_static_member);
  
          var_sp->SetLocationIsConstantValueData(location_is_const_value_data);
        } else {
          // Not ready to parse this variable yet. It might be a global or static
          // variable that is in a function scope and the function in the symbol
          // context wasn't filled in yet
          return var_sp;
        }
      }
      // Cache var_sp even if NULL (the variable was just a specification or was
      // missing vital information to be able to be displayed in the debugger
      // (missing location due to optimization, etc)) so we don't re-parse this
      // DIE over and over later...
      GetDIEToVariable()[die.GetDIE()] = var_sp;
      if (spec_die)
        GetDIEToVariable()[spec_die.GetDIE()] = var_sp;
    }
    return var_sp;
  }
  
  DWARFDIE
  SymbolFileDWARF::FindBlockContainingSpecification(
      const DIERef &func_die_ref, dw_offset_t spec_block_die_offset) {
    // Give the concrete function die specified by "func_die_offset", find the
    // concrete block whose DW_AT_specification or DW_AT_abstract_origin points
    // to "spec_block_die_offset"
    return FindBlockContainingSpecification(DebugInfo()->GetDIE(func_die_ref),
                                            spec_block_die_offset);
  }
  
  DWARFDIE
  SymbolFileDWARF::FindBlockContainingSpecification(
      const DWARFDIE &die, dw_offset_t spec_block_die_offset) {
    if (die) {
      switch (die.Tag()) {
      case DW_TAG_subprogram:
      case DW_TAG_inlined_subroutine:
      case DW_TAG_lexical_block: {
        if (die.GetReferencedDIE(DW_AT_specification).GetOffset() ==
            spec_block_die_offset)
          return die;
  
        if (die.GetReferencedDIE(DW_AT_abstract_origin).GetOffset() ==
            spec_block_die_offset)
          return die;
      } break;
      default:
        break;
      }
  
      // Give the concrete function die specified by "func_die_offset", find the
      // concrete block whose DW_AT_specification or DW_AT_abstract_origin points
      // to "spec_block_die_offset"
      for (DWARFDIE child_die = die.GetFirstChild(); child_die;
           child_die = child_die.GetSibling()) {
        DWARFDIE result_die =
            FindBlockContainingSpecification(child_die, spec_block_die_offset);
        if (result_die)
          return result_die;
      }
    }
  
    return DWARFDIE();
  }
  
  size_t SymbolFileDWARF::ParseVariables(const SymbolContext &sc,
                                         const DWARFDIE &orig_die,
                                         const lldb::addr_t func_low_pc,
                                         bool parse_siblings, bool parse_children,
                                         VariableList *cc_variable_list) {
    if (!orig_die)
      return 0;
  
    VariableListSP variable_list_sp;
  
    size_t vars_added = 0;
    DWARFDIE die = orig_die;
    while (die) {
      dw_tag_t tag = die.Tag();
  
      // Check to see if we have already parsed this variable or constant?
      VariableSP var_sp = GetDIEToVariable()[die.GetDIE()];
      if (var_sp) {
        if (cc_variable_list)
          cc_variable_list->AddVariableIfUnique(var_sp);
      } else {
        // We haven't already parsed it, lets do that now.
        if ((tag == DW_TAG_variable) || (tag == DW_TAG_constant) ||
            (tag == DW_TAG_formal_parameter && sc.function)) {
          if (variable_list_sp.get() == nullptr) {
            DWARFDIE sc_parent_die = GetParentSymbolContextDIE(orig_die);
            dw_tag_t parent_tag = sc_parent_die.Tag();
            switch (parent_tag) {
            case DW_TAG_compile_unit:
            case DW_TAG_partial_unit:
              if (sc.comp_unit != nullptr) {
                variable_list_sp = sc.comp_unit->GetVariableList(false);
                if (variable_list_sp.get() == nullptr) {
                  variable_list_sp = std::make_shared<VariableList>();
                }
              } else {
                GetObjectFile()->GetModule()->ReportError(
                    "parent 0x%8.8" PRIx64 " %s with no valid compile unit in "
                    "symbol context for 0x%8.8" PRIx64 " %s.\n",
                    sc_parent_die.GetID(), sc_parent_die.GetTagAsCString(),
                    orig_die.GetID(), orig_die.GetTagAsCString());
              }
              break;
  
            case DW_TAG_subprogram:
            case DW_TAG_inlined_subroutine:
            case DW_TAG_lexical_block:
              if (sc.function != nullptr) {
                // Check to see if we already have parsed the variables for the
                // given scope
  
                Block *block = sc.function->GetBlock(true).FindBlockByID(
                    sc_parent_die.GetID());
                if (block == nullptr) {
                  // This must be a specification or abstract origin with a
                  // concrete block counterpart in the current function. We need
                  // to find the concrete block so we can correctly add the
                  // variable to it
                  const DWARFDIE concrete_block_die =
                      FindBlockContainingSpecification(
                          GetDIE(sc.function->GetID()),
                          sc_parent_die.GetOffset());
                  if (concrete_block_die)
                    block = sc.function->GetBlock(true).FindBlockByID(
                        concrete_block_die.GetID());
                }
  
                if (block != nullptr) {
                  const bool can_create = false;
                  variable_list_sp = block->GetBlockVariableList(can_create);
                  if (variable_list_sp.get() == nullptr) {
                    variable_list_sp = std::make_shared<VariableList>();
                    block->SetVariableList(variable_list_sp);
                  }
                }
              }
              break;
  
            default:
              GetObjectFile()->GetModule()->ReportError(
                  "didn't find appropriate parent DIE for variable list for "
                  "0x%8.8" PRIx64 " %s.\n",
                  orig_die.GetID(), orig_die.GetTagAsCString());
              break;
            }
          }
  
          if (variable_list_sp) {
            VariableSP var_sp(ParseVariableDIE(sc, die, func_low_pc));
            if (var_sp) {
              variable_list_sp->AddVariableIfUnique(var_sp);
              if (cc_variable_list)
                cc_variable_list->AddVariableIfUnique(var_sp);
              ++vars_added;
            }
          }
        }
      }
  
      bool skip_children = (sc.function == nullptr && tag == DW_TAG_subprogram);
  
      if (!skip_children && parse_children && die.HasChildren()) {
        vars_added += ParseVariables(sc, die.GetFirstChild(), func_low_pc, true,
                                     true, cc_variable_list);
      }
  
      if (parse_siblings)
        die = die.GetSibling();
      else
        die.Clear();
    }
    return vars_added;
  }
  
  /// Collect call site parameters in a DW_TAG_call_site DIE.
  static CallSiteParameterArray
  CollectCallSiteParameters(ModuleSP module, DWARFDIE call_site_die) {
    CallSiteParameterArray parameters;
    for (DWARFDIE child = call_site_die.GetFirstChild(); child.IsValid();
         child = child.GetSibling()) {
      if (child.Tag() != DW_TAG_call_site_parameter)
        continue;
  
      llvm::Optional<DWARFExpression> LocationInCallee;
      llvm::Optional<DWARFExpression> LocationInCaller;
  
      DWARFAttributes attributes;
      const size_t num_attributes = child.GetAttributes(attributes);
  
      // Parse the location at index \p attr_index within this call site parameter
      // DIE, or return None on failure.
      auto parse_simple_location =
          [&](int attr_index) -> llvm::Optional<DWARFExpression> {
        DWARFFormValue form_value;
        if (!attributes.ExtractFormValueAtIndex(attr_index, form_value))
          return {};
        if (!DWARFFormValue::IsBlockForm(form_value.Form()))
          return {};
        auto data = child.GetData();
        uint32_t block_offset = form_value.BlockData() - data.GetDataStart();
        uint32_t block_length = form_value.Unsigned();
        return DWARFExpression(module,
                               DataExtractor(data, block_offset, block_length),
                               child.GetCU());
      };
  
      for (size_t i = 0; i < num_attributes; ++i) {
        dw_attr_t attr = attributes.AttributeAtIndex(i);
        if (attr == DW_AT_location)
          LocationInCallee = parse_simple_location(i);
        if (attr == DW_AT_call_value)
          LocationInCaller = parse_simple_location(i);
      }
  
      if (LocationInCallee && LocationInCaller) {
        CallSiteParameter param = {*LocationInCallee, *LocationInCaller};
        parameters.push_back(param);
      }
    }
    return parameters;
  }
  
  /// Collect call graph edges present in a function DIE.
  static std::vector<std::unique_ptr<lldb_private::CallEdge>>
  CollectCallEdges(ModuleSP module, DWARFDIE function_die) {
    // Check if the function has a supported call site-related attribute.
    // TODO: In the future it may be worthwhile to support call_all_source_calls.
    uint64_t has_call_edges =
        function_die.GetAttributeValueAsUnsigned(DW_AT_call_all_calls, 0);
    if (!has_call_edges)
      return {};
  
    Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
    LLDB_LOG(log, "CollectCallEdges: Found call site info in {0}",
             function_die.GetPubname());
  
    // Scan the DIE for TAG_call_site entries.
    // TODO: A recursive scan of all blocks in the subprogram is needed in order
    // to be DWARF5-compliant. This may need to be done lazily to be performant.
    // For now, assume that all entries are nested directly under the subprogram
    // (this is the kind of DWARF LLVM produces) and parse them eagerly.
    std::vector<std::unique_ptr<CallEdge>> call_edges;
    for (DWARFDIE child = function_die.GetFirstChild(); child.IsValid();
         child = child.GetSibling()) {
      if (child.Tag() != DW_TAG_call_site)
        continue;
  
      llvm::Optional<DWARFDIE> call_origin;
      llvm::Optional<DWARFExpression> call_target;
      addr_t return_pc = LLDB_INVALID_ADDRESS;
  
      DWARFAttributes attributes;
      const size_t num_attributes = child.GetAttributes(attributes);
      for (size_t i = 0; i < num_attributes; ++i) {
        DWARFFormValue form_value;
        if (!attributes.ExtractFormValueAtIndex(i, form_value)) {
          LLDB_LOG(log, "CollectCallEdges: Could not extract TAG_call_site form");
          break;
        }
  
        dw_attr_t attr = attributes.AttributeAtIndex(i);
  
        // Extract DW_AT_call_origin (the call target's DIE).
        if (attr == DW_AT_call_origin) {
          call_origin = form_value.Reference();
          if (!call_origin->IsValid()) {
            LLDB_LOG(log, "CollectCallEdges: Invalid call origin in {0}",
                     function_die.GetPubname());
            break;
          }
        }
  
        // Extract DW_AT_call_return_pc (the PC the call returns to) if it's
        // available. It should only ever be unavailable for tail call edges, in
        // which case use LLDB_INVALID_ADDRESS.
        if (attr == DW_AT_call_return_pc)
          return_pc = form_value.Address();
  
        // Extract DW_AT_call_target (the location of the address of the indirect
        // call).
        if (attr == DW_AT_call_target) {
          if (!DWARFFormValue::IsBlockForm(form_value.Form())) {
            LLDB_LOG(log,
                     "CollectCallEdges: AT_call_target does not have block form");
            break;
          }
  
          auto data = child.GetData();
          uint32_t block_offset = form_value.BlockData() - data.GetDataStart();
          uint32_t block_length = form_value.Unsigned();
          call_target = DWARFExpression(
              module, DataExtractor(data, block_offset, block_length),
              child.GetCU());
        }
      }
      if (!call_origin && !call_target) {
        LLDB_LOG(log, "CollectCallEdges: call site without any call target");
        continue;
      }
  
      // Extract call site parameters.
      CallSiteParameterArray parameters =
          CollectCallSiteParameters(module, child);
  
      std::unique_ptr<CallEdge> edge;
      if (call_origin) {
        LLDB_LOG(log, "CollectCallEdges: Found call origin: {0} (retn-PC: {1:x})",
                 call_origin->GetPubname(), return_pc);
        edge = std::make_unique<DirectCallEdge>(call_origin->GetMangledName(),
                                                return_pc, std::move(parameters));
      } else {
        if (log) {
          StreamString call_target_desc;
          call_target->GetDescription(&call_target_desc, eDescriptionLevelBrief,
                                      LLDB_INVALID_ADDRESS, nullptr);
          LLDB_LOG(log, "CollectCallEdges: Found indirect call target: {0}",
                   call_target_desc.GetString());
        }
        edge = std::make_unique<IndirectCallEdge>(*call_target, return_pc,
                                                  std::move(parameters));
      }
  
      if (log && parameters.size()) {
        for (const CallSiteParameter &param : parameters) {
          StreamString callee_loc_desc, caller_loc_desc;
          param.LocationInCallee.GetDescription(&callee_loc_desc,
                                                eDescriptionLevelBrief,
                                                LLDB_INVALID_ADDRESS, nullptr);
          param.LocationInCaller.GetDescription(&caller_loc_desc,
                                                eDescriptionLevelBrief,
                                                LLDB_INVALID_ADDRESS, nullptr);
          LLDB_LOG(log, "CollectCallEdges: \tparam: {0} => {1}",
                   callee_loc_desc.GetString(), caller_loc_desc.GetString());
        }
      }
  
      call_edges.push_back(std::move(edge));
    }
    return call_edges;
  }
  
  std::vector<std::unique_ptr<lldb_private::CallEdge>>
  SymbolFileDWARF::ParseCallEdgesInFunction(UserID func_id) {
    DWARFDIE func_die = GetDIE(func_id.GetID());
    if (func_die.IsValid())
      return CollectCallEdges(GetObjectFile()->GetModule(), func_die);
    return {};
  }
  
  // PluginInterface protocol
  ConstString SymbolFileDWARF::GetPluginName() { return GetPluginNameStatic(); }
  
  uint32_t SymbolFileDWARF::GetPluginVersion() { return 1; }
  
  void SymbolFileDWARF::Dump(lldb_private::Stream &s) {
    SymbolFile::Dump(s);
    m_index->Dump(s);
  }
  
  void SymbolFileDWARF::DumpClangAST(Stream &s) {
    auto ts_or_err = GetTypeSystemForLanguage(eLanguageTypeC_plus_plus);
    if (!ts_or_err)
      return;
    ClangASTContext *clang =
        llvm::dyn_cast_or_null<ClangASTContext>(&ts_or_err.get());
    if (!clang)
      return;
    clang->Dump(s);
  }
  
  SymbolFileDWARFDebugMap *SymbolFileDWARF::GetDebugMapSymfile() {
    if (m_debug_map_symfile == nullptr && !m_debug_map_module_wp.expired()) {
      lldb::ModuleSP module_sp(m_debug_map_module_wp.lock());
      if (module_sp) {
        m_debug_map_symfile =
            (SymbolFileDWARFDebugMap *)module_sp->GetSymbolFile();
      }
    }
    return m_debug_map_symfile;
  }
  
  SymbolFileDWARFDwp *SymbolFileDWARF::GetDwpSymbolFile() {
    llvm::call_once(m_dwp_symfile_once_flag, [this]() {
      ModuleSpec module_spec;
      module_spec.GetFileSpec() = m_objfile_sp->GetFileSpec();
      module_spec.GetSymbolFileSpec() =
          FileSpec(m_objfile_sp->GetFileSpec().GetPath() + ".dwp");
  
      FileSpecList search_paths = Target::GetDefaultDebugFileSearchPaths();
      FileSpec dwp_filespec =
          Symbols::LocateExecutableSymbolFile(module_spec, search_paths);
      if (FileSystem::Instance().Exists(dwp_filespec)) {
        m_dwp_symfile = SymbolFileDWARFDwp::Create(GetObjectFile()->GetModule(),
                                                   dwp_filespec);
      }
    });
    return m_dwp_symfile.get();
  }
  