Add support for the DWP debug info format

[tberghammer]

Summary

The DWP (DWARF package) format is used to pack multiple dwo files
generated by split-dwarf into a single ELF file to make distributing
them easier. It is part of the DWARFv5 spec and can be generated by
dwp or llvm-dwp from a set of dwo files.

Caviats:

• Only the new version of the dwp format is supported (v2 in GNU numbering schema and v5 in the DWARF spec). The old version (v1) is already deprecated but binutils 2.24 still generates that one.
• Combining DWP files with module debugging is not yet supported.

[tberghammer]

Improve error handling

[tberghammer]

Note about testing: I haven't manage to come up with any good approach so far for testing because only fairly new version of dwp or llvm-dwp can generate the format I am expecting here so adding a new config for the existing test suite seems a bit infeasible and also it would increase the testing time by a non negligible time.

[tberghammer]

Hi Jason,

Can you take a look?

Thanks,
Tamas

[jasonmolenda]

I apologize for taking so long to look at this Tamas, I was in the middle of end-of-release stuff when the patch first came in, and I lost track of it. :/ This all looks fine to me, there was one little question about a DataExtractor ctor call.

source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwp.cpp

68 ↗

(On Diff #108834)

Shouldn't this be passing in an lldb::ByteOrder enum value? Maybe I'm looking at the wrong DataExtractor ctor.

[tberghammer]

source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwp.cpp

68 ↗

(On Diff #108834)

I am creating an llvm::DataExtractor (https://github.com/llvm-mirror/llvm/blob/master/include/llvm/Support/DataExtractor.h#L51) to be able to pass it to llvm::DWARFUnitIndex what is taking it as a bool.

lldb/trunk/include/lldb/lldb-enumerations.h

enum SectionType {
   eSectionTypeDataPointers,
   eSectionTypeDebug,
   eSectionTypeZeroFill,
   eSectionTypeDataObjCMessageRefs, // Pointer to function pointer + selector
   eSectionTypeDataObjCCFStrings, // Objective C const CFString/NSString objects
   eSectionTypeDWARFDebugAbbrev,
   eSectionTypeDWARFDebugAddr,
   eSectionTypeDWARFDebugAranges,
+  eSectionTypeDWARFDebugCuIndex,
   eSectionTypeDWARFDebugFrame,
   eSectionTypeDWARFDebugInfo,
   eSectionTypeDWARFDebugLine,
   eSectionTypeDWARFDebugLoc,
   eSectionTypeDWARFDebugMacInfo,
   eSectionTypeDWARFDebugMacro,
   eSectionTypeDWARFDebugPubNames,
   eSectionTypeDWARFDebugPubTypes,

lldb/trunk/source/Core/Section.cpp

static const char *GetSectionTypeAsCString(lldb::SectionType sect_type) {
   case eSectionTypeDataObjCCFStrings:
     return "objc-cfstrings";
   case eSectionTypeDWARFDebugAbbrev:
     return "dwarf-abbrev";
   case eSectionTypeDWARFDebugAddr:
     return "dwarf-addr";
   case eSectionTypeDWARFDebugAranges:
     return "dwarf-aranges";
+  case eSectionTypeDWARFDebugCuIndex:
+    return "dwarf-cu-index";
   case eSectionTypeDWARFDebugFrame:
     return "dwarf-frame";
   case eSectionTypeDWARFDebugInfo:
     return "dwarf-info";
   case eSectionTypeDWARFDebugLine:
     return "dwarf-line";
   case eSectionTypeDWARFDebugLoc:
     return "dwarf-loc";

lldb/trunk/source/Expression/IRExecutionUnit.cpp

if (record.m_process_address != LLDB_INVALID_ADDRESS) {
     return true;
   }
 
   switch (record.m_sect_type) {
   case lldb::eSectionTypeInvalid:
   case lldb::eSectionTypeDWARFDebugAbbrev:
   case lldb::eSectionTypeDWARFDebugAddr:
   case lldb::eSectionTypeDWARFDebugAranges:
+  case lldb::eSectionTypeDWARFDebugCuIndex:
   case lldb::eSectionTypeDWARFDebugFrame:
   case lldb::eSectionTypeDWARFDebugInfo:
   case lldb::eSectionTypeDWARFDebugLine:
   case lldb::eSectionTypeDWARFDebugLoc:
   case lldb::eSectionTypeDWARFDebugMacInfo:
   case lldb::eSectionTypeDWARFDebugPubNames:
   case lldb::eSectionTypeDWARFDebugPubTypes:
   case lldb::eSectionTypeDWARFDebugRanges:

lldb/trunk/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp

for (SectionHeaderCollIter I = m_section_headers.begin();
       static ConstString g_sect_name_text(".text");
       static ConstString g_sect_name_data(".data");
       static ConstString g_sect_name_bss(".bss");
       static ConstString g_sect_name_tdata(".tdata");
       static ConstString g_sect_name_tbss(".tbss");
       static ConstString g_sect_name_dwarf_debug_abbrev(".debug_abbrev");
       static ConstString g_sect_name_dwarf_debug_addr(".debug_addr");
       static ConstString g_sect_name_dwarf_debug_aranges(".debug_aranges");
+      static ConstString g_sect_name_dwarf_debug_cu_index(".debug_cu_index");
       static ConstString g_sect_name_dwarf_debug_frame(".debug_frame");
       static ConstString g_sect_name_dwarf_debug_info(".debug_info");
       static ConstString g_sect_name_dwarf_debug_line(".debug_line");
       static ConstString g_sect_name_dwarf_debug_loc(".debug_loc");
       static ConstString g_sect_name_dwarf_debug_macinfo(".debug_macinfo");
       static ConstString g_sect_name_dwarf_debug_macro(".debug_macro");
       static ConstString g_sect_name_dwarf_debug_pubnames(".debug_pubnames");
       static ConstString g_sect_name_dwarf_debug_pubtypes(".debug_pubtypes");
for (SectionHeaderCollIter I = m_section_headers.begin();
       // MISSING? .debug_types - Type descriptions from DWARF 4? See
       // http://gcc.gnu.org/wiki/DwarfSeparateTypeInfo
       else if (name == g_sect_name_dwarf_debug_abbrev)
         sect_type = eSectionTypeDWARFDebugAbbrev;
       else if (name == g_sect_name_dwarf_debug_addr)
         sect_type = eSectionTypeDWARFDebugAddr;
       else if (name == g_sect_name_dwarf_debug_aranges)
         sect_type = eSectionTypeDWARFDebugAranges;
+      else if (name == g_sect_name_dwarf_debug_cu_index)
+        sect_type = eSectionTypeDWARFDebugCuIndex;
       else if (name == g_sect_name_dwarf_debug_frame)
         sect_type = eSectionTypeDWARFDebugFrame;
       else if (name == g_sect_name_dwarf_debug_info)
         sect_type = eSectionTypeDWARFDebugInfo;
       else if (name == g_sect_name_dwarf_debug_line)
         sect_type = eSectionTypeDWARFDebugLine;
       else if (name == g_sect_name_dwarf_debug_loc)
         sect_type = eSectionTypeDWARFDebugLoc;
for (SectionHeaderCollIter I = m_section_headers.begin();
         section_sp->SetIsThreadSpecific(is_thread_specific);
       m_sections_ap->AddSection(section_sp);
     }
   }
 
   if (m_sections_ap.get()) {
     if (GetType() == eTypeDebugInfo) {
       static const SectionType g_sections[] = {
-          eSectionTypeDWARFDebugAbbrev,     eSectionTypeDWARFDebugAddr,
-          eSectionTypeDWARFDebugAranges,    eSectionTypeDWARFDebugFrame,
-          eSectionTypeDWARFDebugInfo,       eSectionTypeDWARFDebugLine,
-          eSectionTypeDWARFDebugLoc,        eSectionTypeDWARFDebugMacInfo,
-          eSectionTypeDWARFDebugPubNames,   eSectionTypeDWARFDebugPubTypes,
-          eSectionTypeDWARFDebugRanges,     eSectionTypeDWARFDebugStr,
-          eSectionTypeDWARFDebugStrOffsets, eSectionTypeELFSymbolTable,
+          eSectionTypeDWARFDebugAbbrev,   eSectionTypeDWARFDebugAddr,
+          eSectionTypeDWARFDebugAranges,  eSectionTypeDWARFDebugCuIndex,
+          eSectionTypeDWARFDebugFrame,    eSectionTypeDWARFDebugInfo,
+          eSectionTypeDWARFDebugLine,     eSectionTypeDWARFDebugLoc,
+          eSectionTypeDWARFDebugMacInfo,  eSectionTypeDWARFDebugPubNames,
+          eSectionTypeDWARFDebugPubTypes, eSectionTypeDWARFDebugRanges,
+          eSectionTypeDWARFDebugStr,      eSectionTypeDWARFDebugStrOffsets,
+          eSectionTypeELFSymbolTable,
       };
       SectionList *elf_section_list = m_sections_ap.get();
       for (size_t idx = 0; idx < sizeof(g_sections) / sizeof(g_sections[0]);
            ++idx) {
         SectionType section_type = g_sections[idx];
         SectionSP section_sp(
             elf_section_list->FindSectionByType(section_type, true));
         if (section_sp) {

lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp

if (symbol) {
           case eSectionTypeDataObjCCFStrings:
           case eSectionTypeGoSymtab:
             return eAddressClassData;
 
           case eSectionTypeDebug:
           case eSectionTypeDWARFDebugAbbrev:
           case eSectionTypeDWARFDebugAddr:
           case eSectionTypeDWARFDebugAranges:
+          case eSectionTypeDWARFDebugCuIndex:
           case eSectionTypeDWARFDebugFrame:
           case eSectionTypeDWARFDebugInfo:
           case eSectionTypeDWARFDebugLine:
           case eSectionTypeDWARFDebugLoc:
           case eSectionTypeDWARFDebugMacInfo:
           case eSectionTypeDWARFDebugMacro:
           case eSectionTypeDWARFDebugPubNames:
           case eSectionTypeDWARFDebugPubTypes:

lldb/trunk/source/Plugins/SymbolFile/DWARF/CMakeLists.txt

add_lldb_library(lldbPluginSymbolFileDWARF PLUGIN
   DWARFDIE.cpp
   DWARFDIECollection.cpp
   DWARFFormValue.cpp
   HashedNameToDIE.cpp
   LogChannelDWARF.cpp
   NameToDIE.cpp
   SymbolFileDWARF.cpp
   SymbolFileDWARFDwo.cpp
+  SymbolFileDWARFDwoDwp.cpp
+  SymbolFileDWARFDwp.cpp
   SymbolFileDWARFDebugMap.cpp
   UniqueDWARFASTType.cpp
 
   LINK_LIBS
     clangAST
     clangBasic
     lldbCore
     lldbExpression
     lldbHost
     lldbInterpreter
     lldbSymbol
     lldbTarget
     lldbUtility
     lldbPluginObjCLanguage
     lldbPluginCPlusPlusLanguage
     lldbPluginExpressionParserClang
   LINK_COMPONENTS
+    DebugInfoDWARF
     Support
   )

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h

 class DWARFDebugLine;
 class DWARFDebugPubnames;
 class DWARFDebugRanges;
 class DWARFDeclContext;
 class DWARFDIECollection;
 class DWARFFormValue;
 class SymbolFileDWARFDebugMap;
 class SymbolFileDWARFDwo;
+class SymbolFileDWARFDwp;
 
 #define DIE_IS_BEING_PARSED ((lldb_private::Type *)1)
 
 class SymbolFileDWARF : public lldb_private::SymbolFile,
                         public lldb_private::UserID {
 public:
   friend class SymbolFileDWARFDebugMap;
   friend class SymbolFileDWARFDwo;
protected:
   virtual DIEToClangType &GetForwardDeclDieToClangType() {
     return m_forward_decl_die_to_clang_type;
   }
 
   virtual ClangTypeToDIE &GetForwardDeclClangTypeToDie() {
     return m_forward_decl_clang_type_to_die;
   }
 
+  SymbolFileDWARFDwp *GetDwpSymbolFile();
+
   lldb::ModuleWP m_debug_map_module_wp;
   SymbolFileDWARFDebugMap *m_debug_map_symfile;
+
+  llvm::once_flag m_dwp_symfile_once_flag;
+  std::unique_ptr<SymbolFileDWARFDwp> m_dwp_symfile;
+
   lldb_private::DWARFDataExtractor m_dwarf_data;
 
   DWARFDataSegment m_data_debug_abbrev;
   DWARFDataSegment m_data_debug_addr;
   DWARFDataSegment m_data_debug_aranges;
   DWARFDataSegment m_data_debug_frame;
   DWARFDataSegment m_data_debug_info;
   DWARFDataSegment m_data_debug_line;

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp

 #include "DWARFDebugMacro.h"
 #include "DWARFDebugPubnames.h"
 #include "DWARFDebugRanges.h"
 #include "DWARFDeclContext.h"
 #include "DWARFFormValue.h"
 #include "LogChannelDWARF.h"
 #include "SymbolFileDWARFDebugMap.h"
 #include "SymbolFileDWARFDwo.h"
+#include "SymbolFileDWARFDwp.h"
 
 #include "llvm/Support/FileSystem.h"
 
 #include <map>
 
 #include <ctype.h>
 #include <string.h>
 
SymbolFileDWARF::GetDwoSymbolFileForCompileUnit(
   if (GetDebugMapSymfile())
     return nullptr;
 
   const char *dwo_name = cu_die.GetAttributeValueAsString(
       this, &dwarf_cu, DW_AT_GNU_dwo_name, nullptr);
   if (!dwo_name)
     return nullptr;
 
+  SymbolFileDWARFDwp *dwp_symfile = GetDwpSymbolFile();
+  if (dwp_symfile) {
+    uint64_t dwo_id = cu_die.GetAttributeValueAsUnsigned(this, &dwarf_cu,
+                                                         DW_AT_GNU_dwo_id, 0);
+    std::unique_ptr<SymbolFileDWARFDwo> dwo_symfile =
+        dwp_symfile->GetSymbolFileForDwoId(&dwarf_cu, dwo_id);
+    if (dwo_symfile)
+      return dwo_symfile;
+  }
+
   FileSpec dwo_file(dwo_name, true);
   if (dwo_file.IsRelative()) {
     const char *comp_dir = cu_die.GetAttributeValueAsString(
         this, &dwarf_cu, DW_AT_comp_dir, nullptr);
     if (!comp_dir)
       return nullptr;
 
     dwo_file.SetFile(comp_dir, true);
SymbolFileDWARFDebugMap *SymbolFileDWARF::GetDebugMapSymfile() {
   }
   return m_debug_map_symfile;
 }
 
 DWARFExpression::LocationListFormat
 SymbolFileDWARF::GetLocationListFormat() const {
   return DWARFExpression::RegularLocationList;
 }
+
+SymbolFileDWARFDwp *SymbolFileDWARF::GetDwpSymbolFile() {
+  llvm::call_once(m_dwp_symfile_once_flag, [this]() {
+    FileSpec dwp_filespec(m_obj_file->GetFileSpec().GetPath() + ".dwp", false);
+    if (dwp_filespec.Exists()) {
+      m_dwp_symfile = SymbolFileDWARFDwp::Create(GetObjectFile()->GetModule(),
+                                                 dwp_filespec);
+    }
+  });
+  return m_dwp_symfile.get();
+}

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwoDwp.h

+//===-- SymbolFileDWARFDwoDwp.h ---------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SymbolFileDWARFDwoDwp_SymbolFileDWARFDwoDwp_h_
+#define SymbolFileDWARFDwoDwp_SymbolFileDWARFDwoDwp_h_
+
+// C Includes
+// C++ Includes
+// Other libraries and framework includes
+// Project includes
+#include "SymbolFileDWARFDwo.h"
+#include "SymbolFileDWARFDwp.h"
+
+class SymbolFileDWARFDwoDwp : public SymbolFileDWARFDwo {
+public:
+  SymbolFileDWARFDwoDwp(SymbolFileDWARFDwp *dwp_symfile,
+                        lldb::ObjectFileSP objfile, DWARFCompileUnit *dwarf_cu,
+                        uint64_t dwo_id);
+
+protected:
+  void LoadSectionData(lldb::SectionType sect_type,
+                       lldb_private::DWARFDataExtractor &data) override;
+
+  SymbolFileDWARFDwp *m_dwp_symfile;
+  uint64_t m_dwo_id;
+};
+
+#endif // SymbolFileDWARFDwoDwp_SymbolFileDWARFDwoDwp_h_

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwoDwp.cpp

+//===-- SymbolFileDWARFDwoDwp.cpp -------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SymbolFileDWARFDwoDwp.h"
+
+#include "lldb/Core/Section.h"
+#include "lldb/Expression/DWARFExpression.h"
+#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Utility/LLDBAssert.h"
+
+#include "DWARFCompileUnit.h"
+#include "DWARFDebugInfo.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+SymbolFileDWARFDwoDwp::SymbolFileDWARFDwoDwp(SymbolFileDWARFDwp *dwp_symfile,
+                                             ObjectFileSP objfile,
+                                             DWARFCompileUnit *dwarf_cu,
+                                             uint64_t dwo_id)
+    : SymbolFileDWARFDwo(objfile, dwarf_cu), m_dwp_symfile(dwp_symfile),
+      m_dwo_id(dwo_id) {}
+
+void SymbolFileDWARFDwoDwp::LoadSectionData(lldb::SectionType sect_type,
+                                            DWARFDataExtractor &data) {
+  if (m_dwp_symfile->LoadSectionData(m_dwo_id, sect_type, data))
+    return;
+
+  SymbolFileDWARF::LoadSectionData(sect_type, data);
+}

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwp.h

+//===-- SymbolFileDWARFDwp.h ------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SymbolFileDWARFDwp_SymbolFileDWARFDwp_h_
+#define SymbolFileDWARFDwp_SymbolFileDWARFDwp_h_
+
+// C Includes
+// C++ Includes
+#include <memory>
+
+// Other libraries and framework includes
+#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
+
+// Project includes
+#include "lldb/Core/Module.h"
+
+#include "DWARFDataExtractor.h"
+#include "SymbolFileDWARFDwo.h"
+
+class SymbolFileDWARFDwp {
+public:
+  static std::unique_ptr<SymbolFileDWARFDwp>
+  Create(lldb::ModuleSP module_sp, const lldb_private::FileSpec &file_spec);
+
+  std::unique_ptr<SymbolFileDWARFDwo>
+  GetSymbolFileForDwoId(DWARFCompileUnit *dwarf_cu, uint64_t dwo_id);
+
+  bool LoadSectionData(uint64_t dwo_id, lldb::SectionType sect_type,
+                       lldb_private::DWARFDataExtractor &data);
+
+private:
+  explicit SymbolFileDWARFDwp(lldb::ModuleSP module_sp,
+                              lldb::ObjectFileSP obj_file);
+
+  bool LoadRawSectionData(lldb::SectionType sect_type,
+                          lldb_private::DWARFDataExtractor &data);
+
+  lldb::ObjectFileSP m_obj_file;
+
+  std::mutex m_sections_mutex;
+  std::map<lldb::SectionType, lldb_private::DWARFDataExtractor> m_sections;
+
+  llvm::DWARFUnitIndex m_debug_cu_index;
+  std::map<uint64_t, const llvm::DWARFUnitIndex::Entry *> m_debug_cu_index_map;
+};
+
+#endif // SymbolFileDWARFDwp_SymbolFileDWARFDwp_h_

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwp.cpp

+//===-- SymbolFileDWARFDwp.cpp ----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SymbolFileDWARFDwp.h"
+
+// C Includes
+// C++ Includes
+// Other libraries and framework includes
+// Project includes
+#include "lldb/Core/Section.h"
+#include "lldb/Symbol/ObjectFile.h"
+
+#include "SymbolFileDWARFDwoDwp.h"
+
+static llvm::DWARFSectionKind
+lldbSectTypeToLlvmSectionKind(lldb::SectionType type) {
+  switch (type) {
+  case lldb::eSectionTypeDWARFDebugInfo:
+    return llvm::DW_SECT_INFO;
+  // case lldb::eSectionTypeDWARFDebugTypes:
+  //   return llvm::DW_SECT_TYPES;
+  case lldb::eSectionTypeDWARFDebugAbbrev:
+    return llvm::DW_SECT_ABBREV;
+  case lldb::eSectionTypeDWARFDebugLine:
+    return llvm::DW_SECT_LINE;
+  case lldb::eSectionTypeDWARFDebugLoc:
+    return llvm::DW_SECT_LOC;
+  case lldb::eSectionTypeDWARFDebugStrOffsets:
+    return llvm::DW_SECT_STR_OFFSETS;
+  // case lldb::eSectionTypeDWARFDebugMacinfo:
+  //   return llvm::DW_SECT_MACINFO;
+  case lldb::eSectionTypeDWARFDebugMacro:
+    return llvm::DW_SECT_MACRO;
+  default:
+    // Note: 0 is an invalid dwarf section kind.
+    return llvm::DWARFSectionKind(0);
+  }
+}
+
+std::unique_ptr<SymbolFileDWARFDwp>
+SymbolFileDWARFDwp::Create(lldb::ModuleSP module_sp,
+                           const lldb_private::FileSpec &file_spec) {
+  const lldb::offset_t file_offset = 0;
+  lldb::DataBufferSP file_data_sp;
+  lldb::offset_t file_data_offset = 0;
+  lldb::ObjectFileSP obj_file = lldb_private::ObjectFile::FindPlugin(
+      module_sp, &file_spec, file_offset, file_spec.GetByteSize(), file_data_sp,
+      file_data_offset);
+  if (obj_file == nullptr)
+    return nullptr;
+
+  std::unique_ptr<SymbolFileDWARFDwp> dwp_symfile(
+      new SymbolFileDWARFDwp(module_sp, obj_file));
+
+  lldb_private::DWARFDataExtractor debug_cu_index;
+  if (!dwp_symfile->LoadRawSectionData(lldb::eSectionTypeDWARFDebugCuIndex,
+                                       debug_cu_index))
+    return nullptr;
+
+  llvm::DataExtractor llvm_debug_cu_index(
+      llvm::StringRef(debug_cu_index.PeekCStr(0), debug_cu_index.GetByteSize()),
+      debug_cu_index.GetByteOrder() == lldb::eByteOrderLittle,
+      debug_cu_index.GetAddressByteSize());
+  if (!dwp_symfile->m_debug_cu_index.parse(llvm_debug_cu_index))
+    return nullptr;
+  return dwp_symfile;
+}
+
+SymbolFileDWARFDwp::SymbolFileDWARFDwp(lldb::ModuleSP module_sp,
+                                       lldb::ObjectFileSP obj_file)
+    : m_obj_file(std::move(obj_file)), m_debug_cu_index(llvm::DW_SECT_INFO) {
+  for (const auto &entry : m_debug_cu_index.getRows()) {
+    m_debug_cu_index_map.emplace(entry.getSignature(), &entry);
+  }
+}
+
+std::unique_ptr<SymbolFileDWARFDwo>
+SymbolFileDWARFDwp::GetSymbolFileForDwoId(DWARFCompileUnit *dwarf_cu,
+                                          uint64_t dwo_id) {
+  return std::unique_ptr<SymbolFileDWARFDwo>(
+      new SymbolFileDWARFDwoDwp(this, m_obj_file, dwarf_cu, dwo_id));
+}
+
+bool SymbolFileDWARFDwp::LoadSectionData(
+    uint64_t dwo_id, lldb::SectionType sect_type,
+    lldb_private::DWARFDataExtractor &data) {
+  lldb_private::DWARFDataExtractor section_data;
+  if (!LoadRawSectionData(sect_type, section_data))
+    return false;
+
+  auto it = m_debug_cu_index_map.find(dwo_id);
+  if (it == m_debug_cu_index_map.end())
+    return false;
+
+  auto *offsets =
+      it->second->getOffset(lldbSectTypeToLlvmSectionKind(sect_type));
+  if (offsets) {
+    data.SetData(section_data, offsets->Offset, offsets->Length);
+  } else {
+    data.SetData(section_data, 0, section_data.GetByteSize());
+  }
+  return true;
+}
+
+bool SymbolFileDWARFDwp::LoadRawSectionData(
+    lldb::SectionType sect_type, lldb_private::DWARFDataExtractor &data) {
+  std::lock_guard<std::mutex> lock(m_sections_mutex);
+
+  auto it = m_sections.find(sect_type);
+  if (it != m_sections.end()) {
+    if (it->second.GetByteSize() == 0)
+      return false;
+
+    data = it->second;
+    return true;
+  }
+
+  const lldb_private::SectionList *section_list =
+      m_obj_file->GetSectionList(false /* update_module_section_list */);
+  if (section_list) {
+    lldb::SectionSP section_sp(
+        section_list->FindSectionByType(sect_type, true));
+    if (section_sp) {
+      if (m_obj_file->ReadSectionData(section_sp.get(), data) != 0) {
+        m_sections[sect_type] = data;
+        return true;
+      }
+    }
+  }
+  m_sections[sect_type].Clear();
+  return false;
+}

lldb/trunk/source/Plugins/SymbolVendor/ELF/SymbolVendorELF.cpp

if (dsym_fspec) {
         SymbolVendorELF *symbol_vendor = new SymbolVendorELF(module_sp);
         if (symbol_vendor) {
           // Get the module unified section list and add our debug sections to
           // that.
           SectionList *module_section_list = module_sp->GetSectionList();
           SectionList *objfile_section_list = dsym_objfile_sp->GetSectionList();
 
           static const SectionType g_sections[] = {
-              eSectionTypeDWARFDebugAbbrev,     eSectionTypeDWARFDebugAddr,
-              eSectionTypeDWARFDebugAranges,    eSectionTypeDWARFDebugFrame,
-              eSectionTypeDWARFDebugInfo,       eSectionTypeDWARFDebugLine,
-              eSectionTypeDWARFDebugLoc,        eSectionTypeDWARFDebugMacInfo,
-              eSectionTypeDWARFDebugPubNames,   eSectionTypeDWARFDebugPubTypes,
-              eSectionTypeDWARFDebugRanges,     eSectionTypeDWARFDebugStr,
-              eSectionTypeDWARFDebugStrOffsets, eSectionTypeELFSymbolTable,
+              eSectionTypeDWARFDebugAbbrev,   eSectionTypeDWARFDebugAddr,
+              eSectionTypeDWARFDebugAranges,  eSectionTypeDWARFDebugCuIndex,
+              eSectionTypeDWARFDebugFrame,    eSectionTypeDWARFDebugInfo,
+              eSectionTypeDWARFDebugLine,     eSectionTypeDWARFDebugLoc,
+              eSectionTypeDWARFDebugMacInfo,  eSectionTypeDWARFDebugPubNames,
+              eSectionTypeDWARFDebugPubTypes, eSectionTypeDWARFDebugRanges,
+              eSectionTypeDWARFDebugStr,      eSectionTypeDWARFDebugStrOffsets,
+              eSectionTypeELFSymbolTable,
           };
           for (size_t idx = 0; idx < sizeof(g_sections) / sizeof(g_sections[0]);
                ++idx) {
             SectionType section_type = g_sections[idx];
             SectionSP section_sp(
                 objfile_section_list->FindSectionByType(section_type, true));
             if (section_sp) {
               SectionSP module_section_sp(

lldb/trunk/source/Symbol/ObjectFile.cpp

if (symbol) {
           case eSectionTypeDataObjCMessageRefs:
           case eSectionTypeDataObjCCFStrings:
           case eSectionTypeGoSymtab:
             return eAddressClassData;
           case eSectionTypeDebug:
           case eSectionTypeDWARFDebugAbbrev:
           case eSectionTypeDWARFDebugAddr:
           case eSectionTypeDWARFDebugAranges:
+          case eSectionTypeDWARFDebugCuIndex:
           case eSectionTypeDWARFDebugFrame:
           case eSectionTypeDWARFDebugInfo:
           case eSectionTypeDWARFDebugLine:
           case eSectionTypeDWARFDebugLoc:
           case eSectionTypeDWARFDebugMacInfo:
           case eSectionTypeDWARFDebugMacro:
           case eSectionTypeDWARFDebugPubNames:
           case eSectionTypeDWARFDebugPubTypes: