text: //===-- SymbolFileDWARFDebugMap.cpp ---------------------------------------===//
  //
  // 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 "SymbolFileDWARFDebugMap.h"
  #include "DWARFDebugAranges.h"
  
  #include "lldb/Core/Module.h"
  #include "lldb/Core/ModuleList.h"
  #include "lldb/Core/PluginManager.h"
  #include "lldb/Core/Section.h"
  #include "lldb/Host/FileSystem.h"
  #include "lldb/Utility/DataBufferLLVM.h"
  #include "lldb/Utility/RangeMap.h"
  #include "lldb/Utility/RegularExpression.h"
  #include "lldb/Utility/Timer.h"
  
  //#define DEBUG_OSO_DMAP // DO NOT CHECKIN WITH THIS NOT COMMENTED OUT
  #if defined(DEBUG_OSO_DMAP)
  #include "lldb/Core/StreamFile.h"
  #endif
  
  #include "lldb/Symbol/CompileUnit.h"
  #include "lldb/Symbol/LineTable.h"
  #include "lldb/Symbol/ObjectFile.h"
  #include "lldb/Symbol/SymbolVendor.h"
  #include "lldb/Symbol/TypeMap.h"
  #include "lldb/Symbol/VariableList.h"
  #include "llvm/Support/ScopedPrinter.h"
  
  #include "LogChannelDWARF.h"
  #include "SymbolFileDWARF.h"
  
  #include <memory>
  
  using namespace lldb;
  using namespace lldb_private;
  
  char SymbolFileDWARFDebugMap::ID;
  
  // Subclass lldb_private::Module so we can intercept the
  // "Module::GetObjectFile()" (so we can fixup the object file sections) and
  // also for "Module::GetSymbolFile()" (so we can fixup the symbol file id.
  
  const SymbolFileDWARFDebugMap::FileRangeMap &
  SymbolFileDWARFDebugMap::CompileUnitInfo::GetFileRangeMap(
      SymbolFileDWARFDebugMap *exe_symfile) {
    if (file_range_map_valid)
      return file_range_map;
  
    file_range_map_valid = true;
  
    Module *oso_module = exe_symfile->GetModuleByCompUnitInfo(this);
    if (!oso_module)
      return file_range_map;
  
    ObjectFile *oso_objfile = oso_module->GetObjectFile();
    if (!oso_objfile)
      return file_range_map;
  
    Log *log = GetLog(DWARFLog::DebugMap);
    LLDB_LOGF(
        log,
        "%p: SymbolFileDWARFDebugMap::CompileUnitInfo::GetFileRangeMap ('%s')",
        static_cast<void *>(this),
        oso_module->GetSpecificationDescription().c_str());
  
    std::vector<SymbolFileDWARFDebugMap::CompileUnitInfo *> cu_infos;
    if (exe_symfile->GetCompUnitInfosForModule(oso_module, cu_infos)) {
      for (auto comp_unit_info : cu_infos) {
        Symtab *exe_symtab = exe_symfile->GetObjectFile()->GetSymtab();
        ModuleSP oso_module_sp(oso_objfile->GetModule());
        Symtab *oso_symtab = oso_objfile->GetSymtab();
  
        /// const uint32_t fun_resolve_flags = SymbolContext::Module |
        /// eSymbolContextCompUnit | eSymbolContextFunction;
        // SectionList *oso_sections = oso_objfile->Sections();
        // Now we need to make sections that map from zero based object file
        // addresses to where things ended up in the main executable.
  
        assert(comp_unit_info->first_symbol_index != UINT32_MAX);
        // End index is one past the last valid symbol index
        const uint32_t oso_end_idx = comp_unit_info->last_symbol_index + 1;
        for (uint32_t idx = comp_unit_info->first_symbol_index +
                            2; // Skip the N_SO and N_OSO
             idx < oso_end_idx; ++idx) {
          Symbol *exe_symbol = exe_symtab->SymbolAtIndex(idx);
          if (exe_symbol) {
            if (!exe_symbol->IsDebug())
              continue;
  
            switch (exe_symbol->GetType()) {
            default:
              break;
  
            case eSymbolTypeCode: {
              // For each N_FUN, or function that we run into in the debug map we
              // make a new section that we add to the sections found in the .o
              // file. This new section has the file address set to what the
              // addresses are in the .o file, and the load address is adjusted
              // to match where it ended up in the final executable! We do this
              // before we parse any dwarf info so that when it goes get parsed
              // all section/offset addresses that get registered will resolve
              // correctly to the new addresses in the main executable.
  
              // First we find the original symbol in the .o file's symbol table
              Symbol *oso_fun_symbol = oso_symtab->FindFirstSymbolWithNameAndType(
                  exe_symbol->GetMangled().GetName(Mangled::ePreferMangled),
                  eSymbolTypeCode, Symtab::eDebugNo, Symtab::eVisibilityAny);
              if (oso_fun_symbol) {
                // Add the inverse OSO file address to debug map entry mapping
                exe_symfile->AddOSOFileRange(
                    this, exe_symbol->GetAddressRef().GetFileAddress(),
                    exe_symbol->GetByteSize(),
                    oso_fun_symbol->GetAddressRef().GetFileAddress(),
                    oso_fun_symbol->GetByteSize());
              }
            } break;
  
            case eSymbolTypeData: {
              // For each N_GSYM we remap the address for the global by making a
              // new section that we add to the sections found in the .o file.
              // This new section has the file address set to what the addresses
              // are in the .o file, and the load address is adjusted to match
              // where it ended up in the final executable! We do this before we
              // parse any dwarf info so that when it goes get parsed all
              // section/offset addresses that get registered will resolve
              // correctly to the new addresses in the main executable. We
              // initially set the section size to be 1 byte, but will need to
              // fix up these addresses further after all globals have been
              // parsed to span the gaps, or we can find the global variable
              // sizes from the DWARF info as we are parsing.
  
              // Next we find the non-stab entry that corresponds to the N_GSYM
              // in the .o file
              Symbol *oso_gsym_symbol =
                  oso_symtab->FindFirstSymbolWithNameAndType(
                      exe_symbol->GetMangled().GetName(Mangled::ePreferMangled),
                      eSymbolTypeData, Symtab::eDebugNo, Symtab::eVisibilityAny);
              if (exe_symbol && oso_gsym_symbol && exe_symbol->ValueIsAddress() &&
                  oso_gsym_symbol->ValueIsAddress()) {
                // Add the inverse OSO file address to debug map entry mapping
                exe_symfile->AddOSOFileRange(
                    this, exe_symbol->GetAddressRef().GetFileAddress(),
                    exe_symbol->GetByteSize(),
                    oso_gsym_symbol->GetAddressRef().GetFileAddress(),
                    oso_gsym_symbol->GetByteSize());
              }
            } break;
            }
          }
        }
  
        exe_symfile->FinalizeOSOFileRanges(this);
        // We don't need the symbols anymore for the .o files
        oso_objfile->ClearSymtab();
      }
    }
    return file_range_map;
  }
  
  class DebugMapModule : public Module {
  public:
    DebugMapModule(const ModuleSP &exe_module_sp, uint32_t cu_idx,
                   const FileSpec &file_spec, const ArchSpec &arch,
                   const ConstString *object_name, off_t object_offset,
                   const llvm::sys::TimePoint<> object_mod_time)
        : Module(file_spec, arch, object_name, object_offset, object_mod_time),
          m_exe_module_wp(exe_module_sp), m_cu_idx(cu_idx) {}
  
    ~DebugMapModule() override = default;
  
    SymbolFile *
    GetSymbolFile(bool can_create = true,
                  lldb_private::Stream *feedback_strm = nullptr) override {
      // Scope for locker
      if (m_symfile_up.get() || !can_create)
        return m_symfile_up ? m_symfile_up->GetSymbolFile() : nullptr;
  
      ModuleSP exe_module_sp(m_exe_module_wp.lock());
      if (exe_module_sp) {
        // Now get the object file outside of a locking scope
        ObjectFile *oso_objfile = GetObjectFile();
        if (oso_objfile) {
          std::lock_guard<std::recursive_mutex> guard(m_mutex);
          if (SymbolFile *symfile =
                  Module::GetSymbolFile(can_create, feedback_strm)) {
            // Set a pointer to this class to set our OSO DWARF file know that
            // the DWARF is being used along with a debug map and that it will
            // have the remapped sections that we do below.
            SymbolFileDWARF *oso_symfile =
                SymbolFileDWARFDebugMap::GetSymbolFileAsSymbolFileDWARF(symfile);
  
            if (!oso_symfile)
              return nullptr;
  
            ObjectFile *exe_objfile = exe_module_sp->GetObjectFile();
            SymbolFile *exe_symfile = exe_module_sp->GetSymbolFile();
  
            if (exe_objfile && exe_symfile) {
              oso_symfile->SetDebugMapModule(exe_module_sp);
              // Set the ID of the symbol file DWARF to the index of the OSO
              // shifted left by 32 bits to provide a unique prefix for any
              // UserID's that get created in the symbol file.
              oso_symfile->SetID(((uint64_t)m_cu_idx + 1ull) << 32ull);
            }
            return symfile;
          }
        }
      }
      return nullptr;
    }
  
  protected:
    ModuleWP m_exe_module_wp;
    const uint32_t m_cu_idx;
  };
  
  void SymbolFileDWARFDebugMap::Initialize() {
    PluginManager::RegisterPlugin(GetPluginNameStatic(),
                                  GetPluginDescriptionStatic(), CreateInstance);
  }
  
  void SymbolFileDWARFDebugMap::Terminate() {
    PluginManager::UnregisterPlugin(CreateInstance);
  }
  
  llvm::StringRef SymbolFileDWARFDebugMap::GetPluginDescriptionStatic() {
    return "DWARF and DWARF3 debug symbol file reader (debug map).";
  }
  
  SymbolFile *SymbolFileDWARFDebugMap::CreateInstance(ObjectFileSP objfile_sp) {
    return new SymbolFileDWARFDebugMap(std::move(objfile_sp));
  }
  
  SymbolFileDWARFDebugMap::SymbolFileDWARFDebugMap(ObjectFileSP objfile_sp)
      : SymbolFile(std::move(objfile_sp)), m_flags(), m_compile_unit_infos(),
        m_func_indexes(), m_glob_indexes(),
        m_supports_DW_AT_APPLE_objc_complete_type(eLazyBoolCalculate) {}
  
  SymbolFileDWARFDebugMap::~SymbolFileDWARFDebugMap() = default;
  
  void SymbolFileDWARFDebugMap::InitializeObject() {}
  
  void SymbolFileDWARFDebugMap::InitOSO() {
    if (m_flags.test(kHaveInitializedOSOs))
      return;
  
    m_flags.set(kHaveInitializedOSOs);
  
    // If the object file has been stripped, there is no sense in looking further
    // as all of the debug symbols for the debug map will not be available
    if (m_objfile_sp->IsStripped())
      return;
  
    // Also make sure the file type is some sort of executable. Core files, debug
    // info files (dSYM), object files (.o files), and stub libraries all can
    switch (m_objfile_sp->GetType()) {
    case ObjectFile::eTypeInvalid:
    case ObjectFile::eTypeCoreFile:
    case ObjectFile::eTypeDebugInfo:
    case ObjectFile::eTypeObjectFile:
    case ObjectFile::eTypeStubLibrary:
    case ObjectFile::eTypeUnknown:
    case ObjectFile::eTypeJIT:
      return;
  
    case ObjectFile::eTypeExecutable:
    case ObjectFile::eTypeDynamicLinker:
    case ObjectFile::eTypeSharedLibrary:
      break;
    }
  
    // In order to get the abilities of this plug-in, we look at the list of
    // N_OSO entries (object files) from the symbol table and make sure that
    // these files exist and also contain valid DWARF. If we get any of that then
    // we return the abilities of the first N_OSO's DWARF.
  
    Symtab *symtab = m_objfile_sp->GetSymtab();
    if (symtab) {
      Log *log = GetLog(DWARFLog::DebugMap);
  
      std::vector<uint32_t> oso_indexes;
      // When a mach-o symbol is encoded, the n_type field is encoded in bits
      // 23:16, and the n_desc field is encoded in bits 15:0.
      //
      // To find all N_OSO entries that are part of the DWARF + debug map we find
      // only object file symbols with the flags value as follows: bits 23:16 ==
      // 0x66 (N_OSO) bits 15: 0 == 0x0001 (specifies this is a debug map object
      // file)
      const uint32_t k_oso_symbol_flags_value = 0x660001u;
  
      const uint32_t oso_index_count =
          symtab->AppendSymbolIndexesWithTypeAndFlagsValue(
              eSymbolTypeObjectFile, k_oso_symbol_flags_value, oso_indexes);
  
      if (oso_index_count > 0) {
        symtab->AppendSymbolIndexesWithType(eSymbolTypeCode, Symtab::eDebugYes,
                                            Symtab::eVisibilityAny,
                                            m_func_indexes);
        symtab->AppendSymbolIndexesWithType(eSymbolTypeData, Symtab::eDebugYes,
                                            Symtab::eVisibilityAny,
                                            m_glob_indexes);
  
        symtab->SortSymbolIndexesByValue(m_func_indexes, true);
        symtab->SortSymbolIndexesByValue(m_glob_indexes, true);
  
        for (uint32_t sym_idx : m_func_indexes) {
          const Symbol *symbol = symtab->SymbolAtIndex(sym_idx);
          lldb::addr_t file_addr = symbol->GetAddressRef().GetFileAddress();
          lldb::addr_t byte_size = symbol->GetByteSize();
          DebugMap::Entry debug_map_entry(
              file_addr, byte_size, OSOEntry(sym_idx, LLDB_INVALID_ADDRESS));
          m_debug_map.Append(debug_map_entry);
        }
        for (uint32_t sym_idx : m_glob_indexes) {
          const Symbol *symbol = symtab->SymbolAtIndex(sym_idx);
          lldb::addr_t file_addr = symbol->GetAddressRef().GetFileAddress();
          lldb::addr_t byte_size = symbol->GetByteSize();
          DebugMap::Entry debug_map_entry(
              file_addr, byte_size, OSOEntry(sym_idx, LLDB_INVALID_ADDRESS));
          m_debug_map.Append(debug_map_entry);
        }
        m_debug_map.Sort();
  
        m_compile_unit_infos.resize(oso_index_count);
  
        for (uint32_t i = 0; i < oso_index_count; ++i) {
          const uint32_t so_idx = oso_indexes[i] - 1;
          const uint32_t oso_idx = oso_indexes[i];
          const Symbol *so_symbol = symtab->SymbolAtIndex(so_idx);
          const Symbol *oso_symbol = symtab->SymbolAtIndex(oso_idx);
          if (so_symbol && oso_symbol &&
              so_symbol->GetType() == eSymbolTypeSourceFile &&
              oso_symbol->GetType() == eSymbolTypeObjectFile) {
            m_compile_unit_infos[i].so_file.SetFile(
                so_symbol->GetName().AsCString(), FileSpec::Style::native);
            m_compile_unit_infos[i].oso_path = oso_symbol->GetName();
            m_compile_unit_infos[i].oso_mod_time =
                llvm::sys::toTimePoint(oso_symbol->GetIntegerValue(0));
            uint32_t sibling_idx = so_symbol->GetSiblingIndex();
            // The sibling index can't be less that or equal to the current index
            // "i"
            if (sibling_idx == UINT32_MAX) {
              m_objfile_sp->GetModule()->ReportError(
                  "N_SO in symbol with UID %u has invalid sibling in debug map, "
                  "please file a bug and attach the binary listed in this error",
                  so_symbol->GetID());
            } else {
              const Symbol *last_symbol = symtab->SymbolAtIndex(sibling_idx - 1);
              m_compile_unit_infos[i].first_symbol_index = so_idx;
              m_compile_unit_infos[i].last_symbol_index = sibling_idx - 1;
              m_compile_unit_infos[i].first_symbol_id = so_symbol->GetID();
              m_compile_unit_infos[i].last_symbol_id = last_symbol->GetID();
  
              LLDB_LOGF(log, "Initialized OSO 0x%8.8x: file=%s", i,
                        oso_symbol->GetName().GetCString());
            }
          } else {
            if (oso_symbol == nullptr)
              m_objfile_sp->GetModule()->ReportError(
                  "N_OSO symbol[%u] can't be found, please file a bug and attach "
                  "the binary listed in this error",
                  oso_idx);
            else if (so_symbol == nullptr)
              m_objfile_sp->GetModule()->ReportError(
                  "N_SO not found for N_OSO symbol[%u], please file a bug and "
                  "attach the binary listed in this error",
                  oso_idx);
            else if (so_symbol->GetType() != eSymbolTypeSourceFile)
              m_objfile_sp->GetModule()->ReportError(
                  "N_SO has incorrect symbol type (%u) for N_OSO symbol[%u], "
                  "please file a bug and attach the binary listed in this error",
                  so_symbol->GetType(), oso_idx);
            else if (oso_symbol->GetType() != eSymbolTypeSourceFile)
              m_objfile_sp->GetModule()->ReportError(
                  "N_OSO has incorrect symbol type (%u) for N_OSO symbol[%u], "
                  "please file a bug and attach the binary listed in this error",
                  oso_symbol->GetType(), oso_idx);
          }
        }
      }
    }
  }
  
  Module *SymbolFileDWARFDebugMap::GetModuleByOSOIndex(uint32_t oso_idx) {
    const uint32_t cu_count = GetNumCompileUnits();
    if (oso_idx < cu_count)
      return GetModuleByCompUnitInfo(&m_compile_unit_infos[oso_idx]);
    return nullptr;
  }
  
  Module *SymbolFileDWARFDebugMap::GetModuleByCompUnitInfo(
      CompileUnitInfo *comp_unit_info) {
    if (!comp_unit_info->oso_sp) {
      auto pos = m_oso_map.find(
          {comp_unit_info->oso_path, comp_unit_info->oso_mod_time});
      if (pos != m_oso_map.end()) {
        comp_unit_info->oso_sp = pos->second;
      } else {
        ObjectFile *obj_file = GetObjectFile();
        comp_unit_info->oso_sp = std::make_shared<OSOInfo>();
        m_oso_map[{comp_unit_info->oso_path, comp_unit_info->oso_mod_time}] =
            comp_unit_info->oso_sp;
        const char *oso_path = comp_unit_info->oso_path.GetCString();
        FileSpec oso_file(oso_path);
        ConstString oso_object;
        if (FileSystem::Instance().Exists(oso_file)) {
          FileSystem::Instance().Collect(oso_file);
          // The modification time returned by the FS can have a higher precision
          // than the one from the CU.
          auto oso_mod_time = std::chrono::time_point_cast<std::chrono::seconds>(
              FileSystem::Instance().GetModificationTime(oso_file));
          // A timestamp of 0 means that the linker was in deterministic mode. In
          // that case, we should skip the check against the filesystem last
          // modification timestamp, since it will never match.
          if (comp_unit_info->oso_mod_time != llvm::sys::TimePoint<>() &&
              oso_mod_time != comp_unit_info->oso_mod_time) {
            obj_file->GetModule()->ReportError(
                "debug map object file '%s' has changed (actual time is "
                "%s, debug map time is %s"
                ") since this executable was linked, file will be ignored",
                oso_file.GetPath().c_str(), llvm::to_string(oso_mod_time).c_str(),
                llvm::to_string(comp_unit_info->oso_mod_time).c_str());
            return nullptr;
          }
  
        } else {
          const bool must_exist = true;
  
          if (!ObjectFile::SplitArchivePathWithObject(oso_path, oso_file,
                                                      oso_object, must_exist)) {
            return nullptr;
          }
        }
        // Always create a new module for .o files. Why? Because we use the debug
        // map, to add new sections to each .o file and even though a .o file
        // might not have changed, the sections that get added to the .o file can
        // change.
        ArchSpec oso_arch;
        // Only adopt the architecture from the module (not the vendor or OS)
        // since .o files for "i386-apple-ios" will historically show up as "i386
        // -apple-macosx" due to the lack of a LC_VERSION_MIN_MACOSX or
        // LC_VERSION_MIN_IPHONEOS load command...
        oso_arch.SetTriple(m_objfile_sp->GetModule()
                               ->GetArchitecture()
                               .GetTriple()
                               .getArchName()
                               .str()
                               .c_str());
        comp_unit_info->oso_sp->module_sp = std::make_shared<DebugMapModule>(
            obj_file->GetModule(), GetCompUnitInfoIndex(comp_unit_info), oso_file,
            oso_arch, oso_object ? &oso_object : nullptr, 0,
            oso_object ? comp_unit_info->oso_mod_time : llvm::sys::TimePoint<>());
      }
    }
    if (comp_unit_info->oso_sp)
      return comp_unit_info->oso_sp->module_sp.get();
    return nullptr;
  }
  
  bool SymbolFileDWARFDebugMap::GetFileSpecForSO(uint32_t oso_idx,
                                                 FileSpec &file_spec) {
    if (oso_idx < m_compile_unit_infos.size()) {
      if (m_compile_unit_infos[oso_idx].so_file) {
        file_spec = m_compile_unit_infos[oso_idx].so_file;
        return true;
      }
    }
    return false;
  }
  
  ObjectFile *SymbolFileDWARFDebugMap::GetObjectFileByOSOIndex(uint32_t oso_idx) {
    Module *oso_module = GetModuleByOSOIndex(oso_idx);
    if (oso_module)
      return oso_module->GetObjectFile();
    return nullptr;
  }
  
  SymbolFileDWARF *
  SymbolFileDWARFDebugMap::GetSymbolFile(const SymbolContext &sc) {
    return GetSymbolFile(*sc.comp_unit);
  }
  
  SymbolFileDWARF *
  SymbolFileDWARFDebugMap::GetSymbolFile(const CompileUnit &comp_unit) {
    CompileUnitInfo *comp_unit_info = GetCompUnitInfo(comp_unit);
    if (comp_unit_info)
      return GetSymbolFileByCompUnitInfo(comp_unit_info);
    return nullptr;
  }
  
  ObjectFile *SymbolFileDWARFDebugMap::GetObjectFileByCompUnitInfo(
      CompileUnitInfo *comp_unit_info) {
    Module *oso_module = GetModuleByCompUnitInfo(comp_unit_info);
    if (oso_module)
      return oso_module->GetObjectFile();
    return nullptr;
  }
  
  uint32_t SymbolFileDWARFDebugMap::GetCompUnitInfoIndex(
      const CompileUnitInfo *comp_unit_info) {
    if (!m_compile_unit_infos.empty()) {
      const CompileUnitInfo *first_comp_unit_info = &m_compile_unit_infos.front();
      const CompileUnitInfo *last_comp_unit_info = &m_compile_unit_infos.back();
      if (first_comp_unit_info <= comp_unit_info &&
          comp_unit_info <= last_comp_unit_info)
        return comp_unit_info - first_comp_unit_info;
    }
    return UINT32_MAX;
  }
  
  SymbolFileDWARF *
  SymbolFileDWARFDebugMap::GetSymbolFileByOSOIndex(uint32_t oso_idx) {
    unsigned size = m_compile_unit_infos.size();
    if (oso_idx < size)
      return GetSymbolFileByCompUnitInfo(&m_compile_unit_infos[oso_idx]);
    return nullptr;
  }
  
  SymbolFileDWARF *
  SymbolFileDWARFDebugMap::GetSymbolFileAsSymbolFileDWARF(SymbolFile *sym_file) {
    if (sym_file &&
        sym_file->GetPluginName() == SymbolFileDWARF::GetPluginNameStatic())
      return static_cast<SymbolFileDWARF *>(sym_file);
    return nullptr;
  }
  
  SymbolFileDWARF *SymbolFileDWARFDebugMap::GetSymbolFileByCompUnitInfo(
      CompileUnitInfo *comp_unit_info) {
    if (Module *oso_module = GetModuleByCompUnitInfo(comp_unit_info))
      return GetSymbolFileAsSymbolFileDWARF(oso_module->GetSymbolFile());
    return nullptr;
  }
  
  uint32_t SymbolFileDWARFDebugMap::CalculateAbilities() {
    // In order to get the abilities of this plug-in, we look at the list of
    // N_OSO entries (object files) from the symbol table and make sure that
    // these files exist and also contain valid DWARF. If we get any of that then
    // we return the abilities of the first N_OSO's DWARF.
  
    const uint32_t oso_index_count = GetNumCompileUnits();
    if (oso_index_count > 0) {
      InitOSO();
      if (!m_compile_unit_infos.empty()) {
        return SymbolFile::CompileUnits | SymbolFile::Functions |
               SymbolFile::Blocks | SymbolFile::GlobalVariables |
               SymbolFile::LocalVariables | SymbolFile::VariableTypes |
               SymbolFile::LineTables;
      }
    }
    return 0;
  }
  
  uint32_t SymbolFileDWARFDebugMap::CalculateNumCompileUnits() {
    InitOSO();
    return m_compile_unit_infos.size();
  }
  
  CompUnitSP SymbolFileDWARFDebugMap::ParseCompileUnitAtIndex(uint32_t cu_idx) {
    CompUnitSP comp_unit_sp;
    const uint32_t cu_count = GetNumCompileUnits();
  
    if (cu_idx < cu_count) {
      Module *oso_module = GetModuleByCompUnitInfo(&m_compile_unit_infos[cu_idx]);
      if (oso_module) {
        FileSpec so_file_spec;
        if (GetFileSpecForSO(cu_idx, so_file_spec)) {
          // User zero as the ID to match the compile unit at offset zero in each
          // .o file since each .o file can only have one compile unit for now.
          lldb::user_id_t cu_id = 0;
          m_compile_unit_infos[cu_idx].compile_unit_sp =
              std::make_shared<CompileUnit>(
                  m_objfile_sp->GetModule(), nullptr, so_file_spec, cu_id,
                  eLanguageTypeUnknown, eLazyBoolCalculate);
  
          if (m_compile_unit_infos[cu_idx].compile_unit_sp) {
            SetCompileUnitAtIndex(cu_idx,
                                  m_compile_unit_infos[cu_idx].compile_unit_sp);
          }
        }
      }
      comp_unit_sp = m_compile_unit_infos[cu_idx].compile_unit_sp;
    }
  
    return comp_unit_sp;
  }
  
  SymbolFileDWARFDebugMap::CompileUnitInfo *
  SymbolFileDWARFDebugMap::GetCompUnitInfo(const SymbolContext &sc) {
    return GetCompUnitInfo(*sc.comp_unit);
  }
  
  SymbolFileDWARFDebugMap::CompileUnitInfo *
  SymbolFileDWARFDebugMap::GetCompUnitInfo(const CompileUnit &comp_unit) {
    const uint32_t cu_count = GetNumCompileUnits();
    for (uint32_t i = 0; i < cu_count; ++i) {
      if (&comp_unit == m_compile_unit_infos[i].compile_unit_sp.get())
        return &m_compile_unit_infos[i];
    }
    return nullptr;
  }
  
  size_t SymbolFileDWARFDebugMap::GetCompUnitInfosForModule(
      const lldb_private::Module *module,
      std::vector<CompileUnitInfo *> &cu_infos) {
    const uint32_t cu_count = GetNumCompileUnits();
    for (uint32_t i = 0; i < cu_count; ++i) {
      if (module == GetModuleByCompUnitInfo(&m_compile_unit_infos[i]))
        cu_infos.push_back(&m_compile_unit_infos[i]);
    }
    return cu_infos.size();
  }
  
  llvm::VersionTuple
  SymbolFileDWARFDebugMap::GetProducerVersion(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->GetProducerVersion(comp_unit);
    return {};
  }
  
  lldb::LanguageType
  SymbolFileDWARFDebugMap::ParseLanguage(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseLanguage(comp_unit);
    return eLanguageTypeUnknown;
  }
  
  XcodeSDK SymbolFileDWARFDebugMap::ParseXcodeSDK(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseXcodeSDK(comp_unit);
    return {};
  }
  
  size_t SymbolFileDWARFDebugMap::ParseFunctions(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseFunctions(comp_unit);
    return 0;
  }
  
  bool SymbolFileDWARFDebugMap::ParseLineTable(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseLineTable(comp_unit);
    return false;
  }
  
  bool SymbolFileDWARFDebugMap::ParseDebugMacros(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseDebugMacros(comp_unit);
    return false;
  }
  
  bool SymbolFileDWARFDebugMap::ForEachExternalModule(
      CompileUnit &comp_unit,
      llvm::DenseSet<lldb_private::SymbolFile *> &visited_symbol_files,
      llvm::function_ref<bool(Module &)> f) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ForEachExternalModule(comp_unit, visited_symbol_files, f);
    return false;
  }
  
  bool SymbolFileDWARFDebugMap::ParseSupportFiles(CompileUnit &comp_unit,
                                                  FileSpecList &support_files) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseSupportFiles(comp_unit, support_files);
    return false;
  }
  
  bool SymbolFileDWARFDebugMap::ParseIsOptimized(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseIsOptimized(comp_unit);
    return false;
  }
  
  bool SymbolFileDWARFDebugMap::ParseImportedModules(
      const SymbolContext &sc, std::vector<SourceModule> &imported_modules) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(sc);
    if (oso_dwarf)
      return oso_dwarf->ParseImportedModules(sc, imported_modules);
    return false;
  }
  
  size_t SymbolFileDWARFDebugMap::ParseBlocksRecursive(Function &func) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    CompileUnit *comp_unit = func.GetCompileUnit();
    if (!comp_unit)
      return 0;
  
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(*comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseBlocksRecursive(func);
    return 0;
  }
  
  size_t SymbolFileDWARFDebugMap::ParseTypes(CompileUnit &comp_unit) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
    if (oso_dwarf)
      return oso_dwarf->ParseTypes(comp_unit);
    return 0;
  }
  
  size_t
  SymbolFileDWARFDebugMap::ParseVariablesForContext(const SymbolContext &sc) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    SymbolFileDWARF *oso_dwarf = GetSymbolFile(sc);
    if (oso_dwarf)
      return oso_dwarf->ParseVariablesForContext(sc);
    return 0;
  }
  
  Type *SymbolFileDWARFDebugMap::ResolveTypeUID(lldb::user_id_t type_uid) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    const uint64_t oso_idx = GetOSOIndexFromUserID(type_uid);
    SymbolFileDWARF *oso_dwarf = GetSymbolFileByOSOIndex(oso_idx);
    if (oso_dwarf)
      return oso_dwarf->ResolveTypeUID(type_uid);
    return nullptr;
  }
  
  llvm::Optional<SymbolFile::ArrayInfo>
  SymbolFileDWARFDebugMap::GetDynamicArrayInfoForUID(
      lldb::user_id_t type_uid, const lldb_private::ExecutionContext *exe_ctx) {
    const uint64_t oso_idx = GetOSOIndexFromUserID(type_uid);
    SymbolFileDWARF *oso_dwarf = GetSymbolFileByOSOIndex(oso_idx);
    if (oso_dwarf)
      return oso_dwarf->GetDynamicArrayInfoForUID(type_uid, exe_ctx);
    return llvm::None;
  }
  
  bool SymbolFileDWARFDebugMap::CompleteType(CompilerType &compiler_type) {
    bool success = false;
    if (compiler_type) {
      ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
        if (oso_dwarf->HasForwardDeclForClangType(compiler_type)) {
          oso_dwarf->CompleteType(compiler_type);
          success = true;
          return true;
        }
        return false;
      });
    }
    return success;
  }
  
  uint32_t
  SymbolFileDWARFDebugMap::ResolveSymbolContext(const Address &exe_so_addr,
                                                SymbolContextItem resolve_scope,
                                                SymbolContext &sc) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    uint32_t resolved_flags = 0;
    Symtab *symtab = m_objfile_sp->GetSymtab();
    if (symtab) {
      const addr_t exe_file_addr = exe_so_addr.GetFileAddress();
  
      const DebugMap::Entry *debug_map_entry =
          m_debug_map.FindEntryThatContains(exe_file_addr);
      if (debug_map_entry) {
  
        sc.symbol =
            symtab->SymbolAtIndex(debug_map_entry->data.GetExeSymbolIndex());
  
        if (sc.symbol != nullptr) {
          resolved_flags |= eSymbolContextSymbol;
  
          uint32_t oso_idx = 0;
          CompileUnitInfo *comp_unit_info =
              GetCompileUnitInfoForSymbolWithID(sc.symbol->GetID(), &oso_idx);
          if (comp_unit_info) {
            comp_unit_info->GetFileRangeMap(this);
            Module *oso_module = GetModuleByCompUnitInfo(comp_unit_info);
            if (oso_module) {
              lldb::addr_t oso_file_addr =
                  exe_file_addr - debug_map_entry->GetRangeBase() +
                  debug_map_entry->data.GetOSOFileAddress();
              Address oso_so_addr;
              if (oso_module->ResolveFileAddress(oso_file_addr, oso_so_addr)) {
                resolved_flags |=
                    oso_module->GetSymbolFile()->ResolveSymbolContext(
                        oso_so_addr, resolve_scope, sc);
              }
            }
          }
        }
      }
    }
    return resolved_flags;
  }
  
  uint32_t SymbolFileDWARFDebugMap::ResolveSymbolContext(
      const SourceLocationSpec &src_location_spec,
      SymbolContextItem resolve_scope, SymbolContextList &sc_list) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    const uint32_t initial = sc_list.GetSize();
    const uint32_t cu_count = GetNumCompileUnits();
  
    for (uint32_t i = 0; i < cu_count; ++i) {
      // If we are checking for inlines, then we need to look through all compile
      // units no matter if "file_spec" matches.
      bool resolve = src_location_spec.GetCheckInlines();
  
      if (!resolve) {
        FileSpec so_file_spec;
        if (GetFileSpecForSO(i, so_file_spec))
          resolve =
              FileSpec::Match(src_location_spec.GetFileSpec(), so_file_spec);
      }
      if (resolve) {
        SymbolFileDWARF *oso_dwarf = GetSymbolFileByOSOIndex(i);
        if (oso_dwarf)
          oso_dwarf->ResolveSymbolContext(src_location_spec, resolve_scope,
                                          sc_list);
      }
    }
    return sc_list.GetSize() - initial;
  }
  
  void SymbolFileDWARFDebugMap::PrivateFindGlobalVariables(
      ConstString name, const CompilerDeclContext &parent_decl_ctx,
      const std::vector<uint32_t>
          &indexes, // Indexes into the symbol table that match "name"
      uint32_t max_matches, VariableList &variables) {
    const size_t match_count = indexes.size();
    for (size_t i = 0; i < match_count; ++i) {
      uint32_t oso_idx;
      CompileUnitInfo *comp_unit_info =
          GetCompileUnitInfoForSymbolWithIndex(indexes[i], &oso_idx);
      if (comp_unit_info) {
        SymbolFileDWARF *oso_dwarf = GetSymbolFileByOSOIndex(oso_idx);
        if (oso_dwarf) {
          oso_dwarf->FindGlobalVariables(name, parent_decl_ctx, max_matches,
                                         variables);
          if (variables.GetSize() > max_matches)
            break;
        }
      }
    }
  }
  
  void SymbolFileDWARFDebugMap::FindGlobalVariables(
      ConstString name, const CompilerDeclContext &parent_decl_ctx,
      uint32_t max_matches, VariableList &variables) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    uint32_t total_matches = 0;
  
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      const uint32_t old_size = variables.GetSize();
      oso_dwarf->FindGlobalVariables(name, parent_decl_ctx, max_matches,
                                     variables);
      const uint32_t oso_matches = variables.GetSize() - old_size;
      if (oso_matches > 0) {
        total_matches += oso_matches;
  
        // Are we getting all matches?
        if (max_matches == UINT32_MAX)
          return false; // Yep, continue getting everything
  
        // If we have found enough matches, lets get out
        if (max_matches >= total_matches)
          return true;
  
        // Update the max matches for any subsequent calls to find globals in any
        // other object files with DWARF
        max_matches -= oso_matches;
      }
  
      return false;
    });
  }
  
  void SymbolFileDWARFDebugMap::FindGlobalVariables(
      const RegularExpression &regex, uint32_t max_matches,
      VariableList &variables) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    uint32_t total_matches = 0;
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      const uint32_t old_size = variables.GetSize();
      oso_dwarf->FindGlobalVariables(regex, max_matches, variables);
  
      const uint32_t oso_matches = variables.GetSize() - old_size;
      if (oso_matches > 0) {
        total_matches += oso_matches;
  
        // Are we getting all matches?
        if (max_matches == UINT32_MAX)
          return false; // Yep, continue getting everything
  
        // If we have found enough matches, lets get out
        if (max_matches >= total_matches)
          return true;
  
        // Update the max matches for any subsequent calls to find globals in any
        // other object files with DWARF
        max_matches -= oso_matches;
      }
  
      return false;
    });
  }
  
  int SymbolFileDWARFDebugMap::SymbolContainsSymbolWithIndex(
      uint32_t *symbol_idx_ptr, const CompileUnitInfo *comp_unit_info) {
    const uint32_t symbol_idx = *symbol_idx_ptr;
  
    if (symbol_idx < comp_unit_info->first_symbol_index)
      return -1;
  
    if (symbol_idx <= comp_unit_info->last_symbol_index)
      return 0;
  
    return 1;
  }
  
  int SymbolFileDWARFDebugMap::SymbolContainsSymbolWithID(
      user_id_t *symbol_idx_ptr, const CompileUnitInfo *comp_unit_info) {
    const user_id_t symbol_id = *symbol_idx_ptr;
  
    if (symbol_id < comp_unit_info->first_symbol_id)
      return -1;
  
    if (symbol_id <= comp_unit_info->last_symbol_id)
      return 0;
  
    return 1;
  }
  
  SymbolFileDWARFDebugMap::CompileUnitInfo *
  SymbolFileDWARFDebugMap::GetCompileUnitInfoForSymbolWithIndex(
      uint32_t symbol_idx, uint32_t *oso_idx_ptr) {
    const uint32_t oso_index_count = m_compile_unit_infos.size();
    CompileUnitInfo *comp_unit_info = nullptr;
    if (oso_index_count) {
      comp_unit_info = (CompileUnitInfo *)bsearch(
          &symbol_idx, &m_compile_unit_infos[0], m_compile_unit_infos.size(),
          sizeof(CompileUnitInfo),
          (ComparisonFunction)SymbolContainsSymbolWithIndex);
    }
  
    if (oso_idx_ptr) {
      if (comp_unit_info != nullptr)
        *oso_idx_ptr = comp_unit_info - &m_compile_unit_infos[0];
      else
        *oso_idx_ptr = UINT32_MAX;
    }
    return comp_unit_info;
  }
  
  SymbolFileDWARFDebugMap::CompileUnitInfo *
  SymbolFileDWARFDebugMap::GetCompileUnitInfoForSymbolWithID(
      user_id_t symbol_id, uint32_t *oso_idx_ptr) {
    const uint32_t oso_index_count = m_compile_unit_infos.size();
    CompileUnitInfo *comp_unit_info = nullptr;
    if (oso_index_count) {
      comp_unit_info = (CompileUnitInfo *)::bsearch(
          &symbol_id, &m_compile_unit_infos[0], m_compile_unit_infos.size(),
          sizeof(CompileUnitInfo),
          (ComparisonFunction)SymbolContainsSymbolWithID);
    }
  
    if (oso_idx_ptr) {
      if (comp_unit_info != nullptr)
        *oso_idx_ptr = comp_unit_info - &m_compile_unit_infos[0];
      else
        *oso_idx_ptr = UINT32_MAX;
    }
    return comp_unit_info;
  }
  
  static void RemoveFunctionsWithModuleNotEqualTo(const ModuleSP &module_sp,
                                                  SymbolContextList &sc_list,
                                                  uint32_t start_idx) {
    // We found functions in .o files. Not all functions in the .o files will
    // have made it into the final output file. The ones that did make it into
    // the final output file will have a section whose module matches the module
    // from the ObjectFile for this SymbolFile. When the modules don't match,
    // then we have something that was in a .o file, but doesn't map to anything
    // in the final executable.
    uint32_t i = start_idx;
    while (i < sc_list.GetSize()) {
      SymbolContext sc;
      sc_list.GetContextAtIndex(i, sc);
      if (sc.function) {
        const SectionSP section_sp(
            sc.function->GetAddressRange().GetBaseAddress().GetSection());
        if (section_sp->GetModule() != module_sp) {
          sc_list.RemoveContextAtIndex(i);
          continue;
        }
      }
      ++i;
    }
  }
  
  void SymbolFileDWARFDebugMap::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());
    LLDB_SCOPED_TIMERF("SymbolFileDWARFDebugMap::FindFunctions (name = %s)",
                       name.GetCString());
  
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      uint32_t sc_idx = sc_list.GetSize();
      oso_dwarf->FindFunctions(name, parent_decl_ctx, name_type_mask,
                               include_inlines, sc_list);
      if (!sc_list.IsEmpty()) {
        RemoveFunctionsWithModuleNotEqualTo(m_objfile_sp->GetModule(), sc_list,
                                            sc_idx);
      }
      return false;
    });
  }
  
  void SymbolFileDWARFDebugMap::FindFunctions(const RegularExpression &regex,
                                              bool include_inlines,
                                              SymbolContextList &sc_list) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    LLDB_SCOPED_TIMERF("SymbolFileDWARFDebugMap::FindFunctions (regex = '%s')",
                       regex.GetText().str().c_str());
  
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      uint32_t sc_idx = sc_list.GetSize();
  
      oso_dwarf->FindFunctions(regex, include_inlines, sc_list);
      if (!sc_list.IsEmpty()) {
        RemoveFunctionsWithModuleNotEqualTo(m_objfile_sp->GetModule(), sc_list,
                                            sc_idx);
      }
      return false;
    });
  }
  
  void SymbolFileDWARFDebugMap::GetTypes(SymbolContextScope *sc_scope,
                                         lldb::TypeClass type_mask,
                                         TypeList &type_list) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    LLDB_SCOPED_TIMERF("SymbolFileDWARFDebugMap::GetTypes (type_mask = 0x%8.8x)",
                       type_mask);
  
    SymbolFileDWARF *oso_dwarf = nullptr;
    if (sc_scope) {
      SymbolContext sc;
      sc_scope->CalculateSymbolContext(&sc);
  
      CompileUnitInfo *cu_info = GetCompUnitInfo(sc);
      if (cu_info) {
        oso_dwarf = GetSymbolFileByCompUnitInfo(cu_info);
        if (oso_dwarf)
          oso_dwarf->GetTypes(sc_scope, type_mask, type_list);
      }
    } else {
      ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
        oso_dwarf->GetTypes(sc_scope, type_mask, type_list);
        return false;
      });
    }
  }
  
  std::vector<std::unique_ptr<lldb_private::CallEdge>>
  SymbolFileDWARFDebugMap::ParseCallEdgesInFunction(UserID func_id) {
    uint32_t oso_idx = GetOSOIndexFromUserID(func_id.GetID());
    SymbolFileDWARF *oso_dwarf = GetSymbolFileByOSOIndex(oso_idx);
    if (oso_dwarf)
      return oso_dwarf->ParseCallEdgesInFunction(func_id);
    return {};
  }
  
  TypeSP SymbolFileDWARFDebugMap::FindDefinitionTypeForDWARFDeclContext(
      const DWARFDeclContext &die_decl_ctx) {
    TypeSP type_sp;
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      type_sp = oso_dwarf->FindDefinitionTypeForDWARFDeclContext(die_decl_ctx);
      return ((bool)type_sp);
    });
    return type_sp;
  }
  
  bool SymbolFileDWARFDebugMap::Supports_DW_AT_APPLE_objc_complete_type(
      SymbolFileDWARF *skip_dwarf_oso) {
    if (m_supports_DW_AT_APPLE_objc_complete_type == eLazyBoolCalculate) {
      m_supports_DW_AT_APPLE_objc_complete_type = eLazyBoolNo;
      ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
        if (skip_dwarf_oso != oso_dwarf &&
            oso_dwarf->Supports_DW_AT_APPLE_objc_complete_type(nullptr)) {
          m_supports_DW_AT_APPLE_objc_complete_type = eLazyBoolYes;
          return true;
        }
        return false;
      });
    }
    return m_supports_DW_AT_APPLE_objc_complete_type == eLazyBoolYes;
  }
  
  TypeSP SymbolFileDWARFDebugMap::FindCompleteObjCDefinitionTypeForDIE(
      const DWARFDIE &die, ConstString type_name,
      bool must_be_implementation) {
    // If we have a debug map, we will have an Objective-C symbol whose name is
    // the type name and whose type is eSymbolTypeObjCClass. If we can find that
    // symbol and find its containing parent, we can locate the .o file that will
    // contain the implementation definition since it will be scoped inside the
    // N_SO and we can then locate the SymbolFileDWARF that corresponds to that
    // N_SO.
    SymbolFileDWARF *oso_dwarf = nullptr;
    TypeSP type_sp;
    ObjectFile *module_objfile = m_objfile_sp->GetModule()->GetObjectFile();
    if (module_objfile) {
      Symtab *symtab = module_objfile->GetSymtab();
      if (symtab) {
        Symbol *objc_class_symbol = symtab->FindFirstSymbolWithNameAndType(
            type_name, eSymbolTypeObjCClass, Symtab::eDebugAny,
            Symtab::eVisibilityAny);
        if (objc_class_symbol) {
          // Get the N_SO symbol that contains the objective C class symbol as
          // this should be the .o file that contains the real definition...
          const Symbol *source_file_symbol = symtab->GetParent(objc_class_symbol);
  
          if (source_file_symbol &&
              source_file_symbol->GetType() == eSymbolTypeSourceFile) {
            const uint32_t source_file_symbol_idx =
                symtab->GetIndexForSymbol(source_file_symbol);
            if (source_file_symbol_idx != UINT32_MAX) {
              CompileUnitInfo *compile_unit_info =
                  GetCompileUnitInfoForSymbolWithIndex(source_file_symbol_idx,
                                                       nullptr);
              if (compile_unit_info) {
                oso_dwarf = GetSymbolFileByCompUnitInfo(compile_unit_info);
                if (oso_dwarf) {
                  TypeSP type_sp(oso_dwarf->FindCompleteObjCDefinitionTypeForDIE(
                      die, type_name, must_be_implementation));
                  if (type_sp) {
                    return type_sp;
                  }
                }
              }
            }
          }
        }
      }
    }
  
    // Only search all .o files for the definition if we don't need the
    // implementation because otherwise, with a valid debug map we should have
    // the ObjC class symbol and the code above should have found it.
    if (!must_be_implementation) {
      TypeSP type_sp;
  
      ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
        type_sp = oso_dwarf->FindCompleteObjCDefinitionTypeForDIE(
            die, type_name, must_be_implementation);
        return (bool)type_sp;
      });
  
      return type_sp;
    }
    return TypeSP();
  }
  
  void SymbolFileDWARFDebugMap::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());
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      oso_dwarf->FindTypes(name, parent_decl_ctx, max_matches,
                           searched_symbol_files, types);
      return types.GetSize() >= max_matches;
    });
  }
  
  void SymbolFileDWARFDebugMap::FindTypes(
      llvm::ArrayRef<CompilerContext> context, LanguageSet languages,
      llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
      TypeMap &types) {
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      oso_dwarf->FindTypes(context, languages, searched_symbol_files, types);
      return false;
    });
  }
  
  //
  // uint32_t
  // SymbolFileDWARFDebugMap::FindTypes (const SymbolContext& sc, const
  // RegularExpression& regex, bool append, uint32_t max_matches, Type::Encoding
  // encoding, lldb::user_id_t udt_uid, TypeList& types)
  //{
  //  SymbolFileDWARF *oso_dwarf = GetSymbolFile (sc);
  //  if (oso_dwarf)
  //      return oso_dwarf->FindTypes (sc, regex, append, max_matches, encoding,
  //      udt_uid, types);
  //  return 0;
  //}
  
  CompilerDeclContext SymbolFileDWARFDebugMap::FindNamespace(
      lldb_private::ConstString name,
      const CompilerDeclContext &parent_decl_ctx) {
    std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
    CompilerDeclContext matching_namespace;
  
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      matching_namespace = oso_dwarf->FindNamespace(name, parent_decl_ctx);
  
      return (bool)matching_namespace;
    });
  
    return matching_namespace;
  }
  
  bool SymbolFileDWARFDebugMap::GetCompileOption(const char *option,
                                                 std::string &value,
                                                 CompileUnit *cu) {
    bool success = false;
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      success |= oso_dwarf->GetCompileOption(option, value, cu);
      return success;
    });
    return success;
  }
  
  void SymbolFileDWARFDebugMap::DumpClangAST(Stream &s) {
    ForEachSymbolFile([&s](SymbolFileDWARF *oso_dwarf) -> bool {
      oso_dwarf->DumpClangAST(s);
      // The underlying assumption is that DumpClangAST(...) will obtain the
      // AST from the underlying TypeSystem and therefore we only need to do
      // this once and can stop after the first iteration hence we return true.
      return true;
    });
  }
  
  lldb::CompUnitSP
  SymbolFileDWARFDebugMap::GetCompileUnit(SymbolFileDWARF *oso_dwarf) {
    if (oso_dwarf) {
      const uint32_t cu_count = GetNumCompileUnits();
      for (uint32_t cu_idx = 0; cu_idx < cu_count; ++cu_idx) {
        SymbolFileDWARF *oso_symfile =
            GetSymbolFileByCompUnitInfo(&m_compile_unit_infos[cu_idx]);
        if (oso_symfile == oso_dwarf) {
          if (!m_compile_unit_infos[cu_idx].compile_unit_sp)
            m_compile_unit_infos[cu_idx].compile_unit_sp =
                ParseCompileUnitAtIndex(cu_idx);
  
          return m_compile_unit_infos[cu_idx].compile_unit_sp;
        }
      }
    }
    llvm_unreachable("this shouldn't happen");
  }
  
  SymbolFileDWARFDebugMap::CompileUnitInfo *
  SymbolFileDWARFDebugMap::GetCompileUnitInfo(SymbolFileDWARF *oso_dwarf) {
    if (oso_dwarf) {
      const uint32_t cu_count = GetNumCompileUnits();
      for (uint32_t cu_idx = 0; cu_idx < cu_count; ++cu_idx) {
        SymbolFileDWARF *oso_symfile =
            GetSymbolFileByCompUnitInfo(&m_compile_unit_infos[cu_idx]);
        if (oso_symfile == oso_dwarf) {
          return &m_compile_unit_infos[cu_idx];
        }
      }
    }
    return nullptr;
  }
  
  void SymbolFileDWARFDebugMap::SetCompileUnit(SymbolFileDWARF *oso_dwarf,
                                               const CompUnitSP &cu_sp) {
    if (oso_dwarf) {
      const uint32_t cu_count = GetNumCompileUnits();
      for (uint32_t cu_idx = 0; cu_idx < cu_count; ++cu_idx) {
        SymbolFileDWARF *oso_symfile =
            GetSymbolFileByCompUnitInfo(&m_compile_unit_infos[cu_idx]);
        if (oso_symfile == oso_dwarf) {
          if (m_compile_unit_infos[cu_idx].compile_unit_sp) {
            assert(m_compile_unit_infos[cu_idx].compile_unit_sp.get() ==
                   cu_sp.get());
          } else {
            m_compile_unit_infos[cu_idx].compile_unit_sp = cu_sp;
            SetCompileUnitAtIndex(cu_idx, cu_sp);
          }
        }
      }
    }
  }
  
  CompilerDeclContext
  SymbolFileDWARFDebugMap::GetDeclContextForUID(lldb::user_id_t type_uid) {
    const uint64_t oso_idx = GetOSOIndexFromUserID(type_uid);
    SymbolFileDWARF *oso_dwarf = GetSymbolFileByOSOIndex(oso_idx);
    if (oso_dwarf)
      return oso_dwarf->GetDeclContextForUID(type_uid);
    return CompilerDeclContext();
  }
  
  CompilerDeclContext
  SymbolFileDWARFDebugMap::GetDeclContextContainingUID(lldb::user_id_t type_uid) {
    const uint64_t oso_idx = GetOSOIndexFromUserID(type_uid);
    SymbolFileDWARF *oso_dwarf = GetSymbolFileByOSOIndex(oso_idx);
    if (oso_dwarf)
      return oso_dwarf->GetDeclContextContainingUID(type_uid);
    return CompilerDeclContext();
  }
  
  void SymbolFileDWARFDebugMap::ParseDeclsForContext(
      lldb_private::CompilerDeclContext decl_ctx) {
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      oso_dwarf->ParseDeclsForContext(decl_ctx);
      return true; // Keep iterating
    });
  }
  
  bool SymbolFileDWARFDebugMap::AddOSOFileRange(CompileUnitInfo *cu_info,
                                                lldb::addr_t exe_file_addr,
                                                lldb::addr_t exe_byte_size,
                                                lldb::addr_t oso_file_addr,
                                                lldb::addr_t oso_byte_size) {
    const uint32_t debug_map_idx =
        m_debug_map.FindEntryIndexThatContains(exe_file_addr);
    if (debug_map_idx != UINT32_MAX) {
      DebugMap::Entry *debug_map_entry =
          m_debug_map.FindEntryThatContains(exe_file_addr);
      debug_map_entry->data.SetOSOFileAddress(oso_file_addr);
      addr_t range_size = std::min<addr_t>(exe_byte_size, oso_byte_size);
      if (range_size == 0) {
        range_size = std::max<addr_t>(exe_byte_size, oso_byte_size);
        if (range_size == 0)
          range_size = 1;
      }
      cu_info->file_range_map.Append(
          FileRangeMap::Entry(oso_file_addr, range_size, exe_file_addr));
      return true;
    }
    return false;
  }
  
  void SymbolFileDWARFDebugMap::FinalizeOSOFileRanges(CompileUnitInfo *cu_info) {
    cu_info->file_range_map.Sort();
  #if defined(DEBUG_OSO_DMAP)
    const FileRangeMap &oso_file_range_map = cu_info->GetFileRangeMap(this);
    const size_t n = oso_file_range_map.GetSize();
    printf("SymbolFileDWARFDebugMap::FinalizeOSOFileRanges (cu_info = %p) %s\n",
           cu_info, cu_info->oso_sp->module_sp->GetFileSpec().GetPath().c_str());
    for (size_t i = 0; i < n; ++i) {
      const FileRangeMap::Entry &entry = oso_file_range_map.GetEntryRef(i);
      printf("oso [0x%16.16" PRIx64 " - 0x%16.16" PRIx64
             ") ==> exe [0x%16.16" PRIx64 " - 0x%16.16" PRIx64 ")\n",
             entry.GetRangeBase(), entry.GetRangeEnd(), entry.data,
             entry.data + entry.GetByteSize());
    }
  #endif
  }
  
  lldb::addr_t
  SymbolFileDWARFDebugMap::LinkOSOFileAddress(SymbolFileDWARF *oso_symfile,
                                              lldb::addr_t oso_file_addr) {
    CompileUnitInfo *cu_info = GetCompileUnitInfo(oso_symfile);
    if (cu_info) {
      const FileRangeMap::Entry *oso_range_entry =
          cu_info->GetFileRangeMap(this).FindEntryThatContains(oso_file_addr);
      if (oso_range_entry) {
        const DebugMap::Entry *debug_map_entry =
            m_debug_map.FindEntryThatContains(oso_range_entry->data);
        if (debug_map_entry) {
          const lldb::addr_t offset =
              oso_file_addr - oso_range_entry->GetRangeBase();
          const lldb::addr_t exe_file_addr =
              debug_map_entry->GetRangeBase() + offset;
          return exe_file_addr;
        }
      }
    }
    return LLDB_INVALID_ADDRESS;
  }
  
  bool SymbolFileDWARFDebugMap::LinkOSOAddress(Address &addr) {
    // Make sure this address hasn't been fixed already
    Module *exe_module = GetObjectFile()->GetModule().get();
    Module *addr_module = addr.GetModule().get();
    if (addr_module == exe_module)
      return true; // Address is already in terms of the main executable module
  
    CompileUnitInfo *cu_info = GetCompileUnitInfo(
        GetSymbolFileAsSymbolFileDWARF(addr_module->GetSymbolFile()));
    if (cu_info) {
      const lldb::addr_t oso_file_addr = addr.GetFileAddress();
      const FileRangeMap::Entry *oso_range_entry =
          cu_info->GetFileRangeMap(this).FindEntryThatContains(oso_file_addr);
      if (oso_range_entry) {
        const DebugMap::Entry *debug_map_entry =
            m_debug_map.FindEntryThatContains(oso_range_entry->data);
        if (debug_map_entry) {
          const lldb::addr_t offset =
              oso_file_addr - oso_range_entry->GetRangeBase();
          const lldb::addr_t exe_file_addr =
              debug_map_entry->GetRangeBase() + offset;
          return exe_module->ResolveFileAddress(exe_file_addr, addr);
        }
      }
    }
    return true;
  }
  
  LineTable *SymbolFileDWARFDebugMap::LinkOSOLineTable(SymbolFileDWARF *oso_dwarf,
                                                       LineTable *line_table) {
    CompileUnitInfo *cu_info = GetCompileUnitInfo(oso_dwarf);
    if (cu_info)
      return line_table->LinkLineTable(cu_info->GetFileRangeMap(this));
    return nullptr;
  }
  
  size_t
  SymbolFileDWARFDebugMap::AddOSOARanges(SymbolFileDWARF *dwarf2Data,
                                         DWARFDebugAranges *debug_aranges) {
    size_t num_line_entries_added = 0;
    if (debug_aranges && dwarf2Data) {
      CompileUnitInfo *compile_unit_info = GetCompileUnitInfo(dwarf2Data);
      if (compile_unit_info) {
        const FileRangeMap &file_range_map =
            compile_unit_info->GetFileRangeMap(this);
        for (size_t idx = 0; idx < file_range_map.GetSize(); idx++) {
          const FileRangeMap::Entry *entry = file_range_map.GetEntryAtIndex(idx);
          if (entry) {
            debug_aranges->AppendRange(dwarf2Data->GetID(), entry->GetRangeBase(),
                                       entry->GetRangeEnd());
            num_line_entries_added++;
          }
        }
      }
    }
    return num_line_entries_added;
  }
  
  std::vector<DataBufferSP>
  SymbolFileDWARFDebugMap::GetASTData(lldb::LanguageType language) {
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_MAP));
  
    std::vector<DataBufferSP> ast_datas;
    if (language != eLanguageTypeSwift) {
      if (log)
        log->Printf("SymbolFileDWARFDebugMap::%s() - ignoring because not Swift",
                    __FUNCTION__);
      return ast_datas;
    }
  
    Symtab *symtab = m_objfile_sp->GetSymtab();
    if (!symtab) {
      if (log)
        log->Printf("SymbolFileDWARFDebugMap::%s() - ignoring because the obj "
                    "file has no symbol table",
                    __FUNCTION__);
      return ast_datas;
    }
  
    uint32_t next_idx = 0;
    bool done = false;
    do {
      Symbol *symbol =
          symtab->FindSymbolWithType(eSymbolTypeASTFile, Symtab::eDebugAny,
                                     Symtab::eVisibilityAny, next_idx);
      if (symbol == nullptr) {
        // We didn't find any more symbols of type eSymbolTypeASTFile.  We are
        // done looping for them.
        done = true;
      } else {
        // Try to load the specified file.
        FileSpec file_spec(symbol->GetName().GetCString());
        bool exists = FileSystem::Instance().Exists(file_spec);
        if (!exists)
          if (file_spec.GetDirectory().IsEmpty() && m_objfile_sp) {
            // For relative paths, search next to the binary.
            file_spec.GetDirectory() = m_objfile_sp->GetFileSpec().GetDirectory();
            exists = FileSystem::Instance().Exists(file_spec);
          }
        if (exists) {
          // We found the source data for the AST data blob.
          // Read it in and add it to our return vector.
          std::shared_ptr<DataBufferLLVM> data_buf_sp 
                  = FileSystem::Instance().CreateDataBuffer(file_spec.GetPath());
          if (data_buf_sp) {
            ast_datas.push_back(data_buf_sp);
            if (log)
              log->Printf("SymbolFileDWARFDebugMap::%s() - found and loaded AST "
                          "data from file %s",
                          __FUNCTION__, file_spec.GetPath().c_str());
          } else if (log) {
            if (log)
              log->Printf("SymbolFileDWARFDebugMap::%s() - got empty data buffer "
                          "SP from extant file %s",
                          __FUNCTION__, file_spec.GetPath().c_str());        
          }
        } else {
          if (log)
            log->Printf("SymbolFileDWARFDebugMap::%s() - found reference to AST "
                        "file %s, but could not find the file, ignoring",
                        __FUNCTION__, file_spec.GetPath().c_str());
        }
  
        // Regardless of whether we could find the specified file, start the next
        // symbol search at the index past the one we just found.
        ++next_idx;
      }
    } while (!done);
  
    // Return the vector of AST data blobs
    if (log)
      log->Printf("SymbolFileDWARFDebugMap::%s() - returning %d AST data blobs",
                  __FUNCTION__, (int)ast_datas.size());
  
    return ast_datas;
  }
  
  ModuleList SymbolFileDWARFDebugMap::GetDebugInfoModules() {
    ModuleList oso_modules;
    ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
      ObjectFile *oso_objfile = oso_dwarf->GetObjectFile();
      if (oso_objfile) {
        ModuleSP module_sp = oso_objfile->GetModule();
        if (module_sp)
          oso_modules.Append(module_sp);
      }
      return false; // Keep iterating
    });
    return oso_modules;
  }
  