[LLDB] - Add basic support for .debug_rnglists section (DWARF5)

[grimar]

Summary

This adds a basic support of the .debug_rnglists section.
Only the DW_RLE_start_length and DW_RLE_end_of_list entries are supported.

[clayborg]

Just add a switch statement when handling the encodings and a lldbassert as mentioned in inlined comments and this will be good to go.

source/Plugins/SymbolFile/DWARF/DWARFDebugRanges.cpp

134–144 ↗

(On Diff #168642)

Use a switch statement here? We also want to use a lldbassert for any non supported encodings (in the default case of the switch statement) so we know if/when a compiler starts emitting an encoding we don't yet support when running the test suite with assertions enabled. That will let us know why things are failing.

[clayborg]

For space savings it seems like we would want to support the DW_RLE_base_address and DW_RLE_offset_pair pretty soon.

[grimar]

• Addressed review comments.

source/Plugins/SymbolFile/DWARF/DWARFDebugRanges.cpp

134–144 ↗

(On Diff #168642)

Thanks! I was wondering if I can use some kind of an assert here. Because I noticed that usually lldb just return false
when is unable to parse some debug section (like a case of unknown form or attribute) or tries to skip the unknown constructions.
Having an assert definitely can simplify the further support here.

[grimar]

In D52981#1257888, @clayborg wrote:

For space savings it seems like we would want to support the DW_RLE_base_address and DW_RLE_offset_pair pretty soon.

I am working on a follow-up patch to support those.

[xbolva00]

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

163

variable is not used anywhere

[grimar]

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

163

Removed in r345720, thanks!

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

enum SectionType {
   eSectionTypeGoSymtab,
   eSectionTypeAbsoluteAddress, // Dummy section for symbols with absolute
                                // address
   eSectionTypeDWARFGNUDebugAltLink,
   eSectionTypeDWARFDebugTypes, // DWARF .debug_types section
   eSectionTypeDWARFDebugNames, // DWARF v5 .debug_names
   eSectionTypeOther,
   eSectionTypeDWARFDebugLineStr, // DWARF v5 .debug_line_str
+  eSectionTypeDWARFDebugRngLists, // DWARF v5 .debug_rnglists
 };
 
 FLAGS_ENUM(EmulateInstructionOptions){
     eEmulateInstructionOptionNone = (0u),
     eEmulateInstructionOptionAutoAdvancePC = (1u << 0),
     eEmulateInstructionOptionIgnoreConditions = (1u << 1)};
 
 FLAGS_ENUM(FunctionNameType){

lldb/trunk/lit/Breakpoint/Inputs/debug_rnglist_basic.yaml

+--- !ELF
+FileHeader:      
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_EXEC
+  Machine:         EM_X86_64
+  Entry:           0x0000000000400440
+Sections:        
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Address:         0x0000000000400440
+    AddressAlign:    0x0000000000000010
+    Content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
+  - Name:            .debug_str_offsets
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000001
+    Content:         200000000500000000000000230000002C0000005D00000065000000690000006D000000
+  - Name:            .debug_str
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_MERGE, SHF_STRINGS ]
+    AddressAlign:    0x0000000000000001
+    Content:         636C616E672076657273696F6E20382E302E3020287472756E6B203334333438372900746573742E637070002F686F6D652F756D622F74657374735F323031382F313033726E676C697374732F6C6C64622F63726561746574657374005F5A337A656476007A656400696E74006D61696E00
+  - Name:            .debug_abbrev
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000001
+    Content:         011101252513050325721710171B251101551774170000022E001101120640186E2503253A0B3B0B49133F190000032E0011011206401803253A0B3B0B49133F19000004240003253E0B0B0B000000
+  - Name:            .debug_info
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000001
+    Content:         580000000500010800000000010004000108000000000000000200000000000000000C0000000C0000000220054000000000000B000000015603040101570000000330054000000000001A0000000156060105570000000405050400
+  - Name:            .debug_rnglists
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000001
+    Content:         1D00000005000800000000000720054000000000000B0730054000000000001A00
+  - Name:            .debug_macinfo
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000001
+    Content:         '00'
+  - Name:            .debug_line
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000001
+    Content:         82000000050008004C000000010101FB0E0D00010101010000000100000101011F010000000003011F020F051E023100000000F7B7492A97F18E69F7EC76B19E9024873100000000F7B7492A97F18E69F7EC76B19E90248700090220054000000000000105020A4B020700010100090230054000000000001605090AE5050206580206000101
+  - Name:            .debug_line_str
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_MERGE, SHF_STRINGS ]
+    AddressAlign:    0x0000000000000001
+    Content:         2F686F6D652F756D622F74657374735F323031382F313033726E676C697374732F6C6C64622F6372656174657465737400746573742E63707000
+Symbols:         
+...

lldb/trunk/lit/Breakpoint/debug_rnglist_basic.test

+# RUN: yaml2obj %p/Inputs/debug_rnglist_basic.yaml > %ttest
+# RUN: lldb-test breakpoints %ttest %s | FileCheck %s
+
+# The following code and invocation were used to produce yaml file,
+# which was manually reduced after that.
+# clang -O0 -gdwarf-5 test.cpp -o test -fuse-ld=lld -ffunction-sections
+#
+# //test.cpp:
+# int zed() { 
+#  return 1;
+# }
+#
+# int main() {
+#  return zed();
+# }
+#
+# clang and LLD versions were 8.0.0 (trunk 343487)
+#
+# Output file contains .debug_rnglists section with basic entries:
+# DW_RLE_start_length and DW_RLE_end_of_list.
+# If LLDB would not be able to parse the section and entries correctly,
+# then reported location would be incorrect.
+
+b main
+# CHECK-LABEL: b main
+# CHECK: Address: {{.*}}`main + 15 at test.cpp:6:9
+
+b zed
+# CHECK-LABEL: b zed
+# CHECK: Address: {{.*}}`zed() + 4 at test.cpp:2:2

lldb/trunk/source/Core/Section.cpp

const char *Section::GetTypeAsCString() const {
   case eSectionTypeDWARFDebugMacro:
     return "dwarf-macro";
   case eSectionTypeDWARFDebugPubNames:
     return "dwarf-pubnames";
   case eSectionTypeDWARFDebugPubTypes:
     return "dwarf-pubtypes";
   case eSectionTypeDWARFDebugRanges:
     return "dwarf-ranges";
+  case eSectionTypeDWARFDebugRngLists:
+    return "dwarf-rnglists";
   case eSectionTypeDWARFDebugStr:
     return "dwarf-str";
   case eSectionTypeDWARFDebugStrOffsets:
     return "dwarf-str-offsets";
   case eSectionTypeDWARFDebugTypes:
     return "dwarf-types";
   case eSectionTypeDWARFDebugNames:
     return "dwarf-names";

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

for (SectionHeaderCollIter I = m_section_headers.begin();
       static ConstString g_sect_name_dwarf_debug_line_str(".debug_line_str");
       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_names(".debug_names");
       static ConstString g_sect_name_dwarf_debug_pubnames(".debug_pubnames");
       static ConstString g_sect_name_dwarf_debug_pubtypes(".debug_pubtypes");
       static ConstString g_sect_name_dwarf_debug_ranges(".debug_ranges");
+      static ConstString g_sect_name_dwarf_debug_rnglists(".debug_rnglists");
       static ConstString g_sect_name_dwarf_debug_str(".debug_str");
       static ConstString g_sect_name_dwarf_debug_str_offsets(
           ".debug_str_offsets");
       static ConstString g_sect_name_dwarf_debug_abbrev_dwo(
           ".debug_abbrev.dwo");
       static ConstString g_sect_name_dwarf_debug_info_dwo(".debug_info.dwo");
       static ConstString g_sect_name_dwarf_debug_line_dwo(".debug_line.dwo");
       static ConstString g_sect_name_dwarf_debug_line_str_dwo(".debug_line_str.dwo");
for (SectionHeaderCollIter I = m_section_headers.begin();
       else if (name == g_sect_name_dwarf_debug_names)
         sect_type = eSectionTypeDWARFDebugNames;
       else if (name == g_sect_name_dwarf_debug_pubnames)
         sect_type = eSectionTypeDWARFDebugPubNames;
       else if (name == g_sect_name_dwarf_debug_pubtypes)
         sect_type = eSectionTypeDWARFDebugPubTypes;
       else if (name == g_sect_name_dwarf_debug_ranges)
         sect_type = eSectionTypeDWARFDebugRanges;
+      else if (name == g_sect_name_dwarf_debug_rnglists)
+        sect_type = eSectionTypeDWARFDebugRngLists;
       else if (name == g_sect_name_dwarf_debug_str)
         sect_type = eSectionTypeDWARFDebugStr;
       else if (name == g_sect_name_dwarf_debug_types)
         sect_type = eSectionTypeDWARFDebugTypes;
       else if (name == g_sect_name_dwarf_debug_str_offsets)
         sect_type = eSectionTypeDWARFDebugStrOffsets;
       else if (name == g_sect_name_dwarf_debug_abbrev_dwo)
         sect_type = eSectionTypeDWARFDebugAbbrev;

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

if (symbol) {
           case eSectionTypeDWARFDebugLineStr:
           case eSectionTypeDWARFDebugLoc:
           case eSectionTypeDWARFDebugMacInfo:
           case eSectionTypeDWARFDebugMacro:
           case eSectionTypeDWARFDebugNames:
           case eSectionTypeDWARFDebugPubNames:
           case eSectionTypeDWARFDebugPubTypes:
           case eSectionTypeDWARFDebugRanges:
+          case eSectionTypeDWARFDebugRngLists:
           case eSectionTypeDWARFDebugStr:
           case eSectionTypeDWARFDebugStrOffsets:
           case eSectionTypeDWARFDebugTypes:
           case eSectionTypeDWARFAppleNames:
           case eSectionTypeDWARFAppleTypes:
           case eSectionTypeDWARFAppleNamespaces:
           case eSectionTypeDWARFAppleObjC:
           case eSectionTypeDWARFGNUDebugAltLink:
if (section_name == g_sect_name_dwarf_debug_macinfo)
     return eSectionTypeDWARFDebugMacInfo;
   if (section_name == g_sect_name_dwarf_debug_names)
     return eSectionTypeDWARFDebugNames;
   if (section_name == g_sect_name_dwarf_debug_pubnames)
     return eSectionTypeDWARFDebugPubNames;
   if (section_name == g_sect_name_dwarf_debug_pubtypes)
     return eSectionTypeDWARFDebugPubTypes;
   if (section_name == g_sect_name_dwarf_debug_ranges)
-    return eSectionTypeDWARFDebugRanges;
+    return eSectionTypeDWARFDebugRanges; 
   if (section_name == g_sect_name_dwarf_debug_str)
     return eSectionTypeDWARFDebugStr;
   if (section_name == g_sect_name_dwarf_debug_types)
     return eSectionTypeDWARFDebugTypes;
   if (section_name == g_sect_name_dwarf_apple_names)
     return eSectionTypeDWARFAppleNames;
   if (section_name == g_sect_name_dwarf_apple_types)
     return eSectionTypeDWARFAppleTypes;

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

size_t DWARFDebugInfoEntry::GetAttributeAddressRanges(
     DWARFRangeList &ranges, bool check_hi_lo_pc,
     bool check_specification_or_abstract_origin) const {
   ranges.Clear();
 
   dw_offset_t debug_ranges_offset = GetAttributeValueAsUnsigned(
       dwarf2Data, cu, DW_AT_ranges, DW_INVALID_OFFSET,
       check_specification_or_abstract_origin);
   if (debug_ranges_offset != DW_INVALID_OFFSET) {
-    DWARFDebugRanges *debug_ranges = dwarf2Data->DebugRanges();
-
-    debug_ranges->FindRanges(cu->GetRangesBase(), debug_ranges_offset, ranges);
+    if (DWARFDebugRanges *debug_ranges = dwarf2Data->DebugRanges())
+      debug_ranges->FindRanges(cu->GetRangesBase(), debug_ranges_offset,
+                               ranges);
     ranges.Slide(cu->GetBaseAddress());
   } else if (check_hi_lo_pc) {
     dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
     dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
     if (GetAttributeAddressRange(dwarf2Data, cu, lo_pc, hi_pc,
                                  LLDB_INVALID_ADDRESS,
                                  check_specification_or_abstract_origin)) {
       if (lo_pc < hi_pc)

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

 #include "DWARFDIE.h"
 #include "SymbolFileDWARF.h"
 
 #include <map>
 
 class DWARFDebugRanges {
 public:
   DWARFDebugRanges();
-  ~DWARFDebugRanges();
-  void Extract(SymbolFileDWARF *dwarf2Data);
+  virtual ~DWARFDebugRanges();
+  virtual void Extract(SymbolFileDWARF *dwarf2Data);
+
   static void Dump(lldb_private::Stream &s,
                    const lldb_private::DWARFDataExtractor &debug_ranges_data,
                    lldb::offset_t *offset_ptr, dw_addr_t cu_base_addr);
   bool FindRanges(dw_addr_t debug_ranges_base,
                   dw_offset_t debug_ranges_offset,
                   DWARFRangeList &range_list) const;
 
 protected:
   bool Extract(SymbolFileDWARF *dwarf2Data, lldb::offset_t *offset_ptr,
                DWARFRangeList &range_list);
 
   typedef std::map<dw_offset_t, DWARFRangeList> range_map;
   typedef range_map::iterator range_map_iterator;
   typedef range_map::const_iterator range_map_const_iterator;
   range_map m_range_map;
 };
 
+// DWARF v5 .debug_rnglists section.
+class DWARFDebugRngLists : public DWARFDebugRanges {
+public:
+  void Extract(SymbolFileDWARF *dwarf2Data) override;
+
+protected:
+  bool ExtractRangeList(const lldb_private::DWARFDataExtractor &data,
+                        uint8_t addrSize, lldb::offset_t *offset_ptr,
+                        DWARFRangeList &list);
+
+  std::vector<uint64_t> Offsets;
+};
+
 #endif // SymbolFileDWARF_DWARFDebugRanges_h_

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

bool DWARFDebugRanges::FindRanges(dw_addr_t debug_ranges_base,
   dw_addr_t debug_ranges_address = debug_ranges_base + debug_ranges_offset;
   range_map_const_iterator pos = m_range_map.find(debug_ranges_address);
   if (pos != m_range_map.end()) {
     range_list = pos->second;
     return true;
   }
   return false;
 }
+
+bool DWARFDebugRngLists::ExtractRangeList(const DWARFDataExtractor &data,
+                                          uint8_t addrSize,
+                                          lldb::offset_t *offset_ptr,
+                                          DWARFRangeList &rangeList) {
+  rangeList.Clear();
+
+  bool error = false;
+  while (!error) {
+    switch (data.GetU8(offset_ptr)) {
+    case DW_RLE_end_of_list:
+      return true;
+
+    case DW_RLE_start_length: {
+      dw_addr_t begin = data.GetMaxU64(offset_ptr, addrSize);
+      dw_addr_t len = data.GetULEB128(offset_ptr);
+      rangeList.Append(DWARFRangeList::Entry(begin, len));
+      break;
+    }
+
+    default:
+      // Next encodings are not yet supported:
+      // DW_RLE_base_addressx, DW_RLE_startx_endx, DW_RLE_startx_length,
+      // DW_RLE_offset_pair, DW_RLE_base_address, DW_RLE_start_end
+      lldbassert(0 && "unknown range list entry encoding");
+      error = true;
+    }
+  }
+
+  return false;
+}
+
+void DWARFDebugRngLists::Extract(SymbolFileDWARF *dwarf2Data) {
+  const DWARFDataExtractor &data = dwarf2Data->get_debug_rnglists_data();
+  lldb::offset_t offset = 0;
+
+  uint64_t length = data.GetU32(&offset);
+  bool isDwarf64 = false;
+  if (length == 0xffffffff) {
+    length = data.GetU64(&offset);
+    isDwarf64 = true;
+  }
+  lldb::offset_t end = offset + length;
+
+  // Check version.
+  if (data.GetU16(&offset) < 5)
+    return;
+
+  uint8_t addrSize = data.GetU8(&offset);
+
+  // We do not support non-zero segment selector size.
+  if (data.GetU8(&offset) != 0) {
+    lldbassert(0 && "not implemented");
+    return;
+  }
+
+  uint32_t offsetsAmount = data.GetU32(&offset);
+  for (uint32_t i = 0; i < offsetsAmount; ++i)
+    Offsets.push_back(data.GetPointer(&offset));
+
+  lldb::offset_t listOffset = offset;
+  DWARFRangeList rangeList;
+  while (offset < end && ExtractRangeList(data, addrSize, &offset, rangeList)) {
+    rangeList.Sort();
+    m_range_map[listOffset] = rangeList;
+    listOffset = offset;
+  }
+}

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

 class DWARFAbbreviationDeclarationSet;
 class DWARFileUnit;
 class DWARFDebugAbbrev;
 class DWARFDebugAranges;
 class DWARFDebugInfo;
 class DWARFDebugInfoEntry;
 class DWARFDebugLine;
 class DWARFDebugRanges;
+class DWARFDebugRngLists;
 class DWARFDeclContext;
 class DWARFDIECollection;
 class DWARFFormValue;
 class SymbolFileDWARFDebugMap;
 class SymbolFileDWARFDwo;
 class SymbolFileDWARFDwp;
 
 #define DIE_IS_BEING_PARSED ((lldb_private::Type *)1)
public:
   const lldb_private::DWARFDataExtractor &get_debug_aranges_data();
   const lldb_private::DWARFDataExtractor &get_debug_frame_data();
   const lldb_private::DWARFDataExtractor &get_debug_info_data();
   const lldb_private::DWARFDataExtractor &get_debug_line_data();
   const lldb_private::DWARFDataExtractor &get_debug_line_str_data();
   const lldb_private::DWARFDataExtractor &get_debug_macro_data();
   const lldb_private::DWARFDataExtractor &get_debug_loc_data();
   const lldb_private::DWARFDataExtractor &get_debug_ranges_data();
+  const lldb_private::DWARFDataExtractor &get_debug_rnglists_data();
   const lldb_private::DWARFDataExtractor &get_debug_str_data();
   const lldb_private::DWARFDataExtractor &get_debug_str_offsets_data();
   const lldb_private::DWARFDataExtractor &get_debug_types_data();
   const lldb_private::DWARFDataExtractor &get_apple_names_data();
   const lldb_private::DWARFDataExtractor &get_apple_types_data();
   const lldb_private::DWARFDataExtractor &get_apple_namespaces_data();
   const lldb_private::DWARFDataExtractor &get_apple_objc_data();
   const lldb_private::DWARFDataExtractor &get_gnu_debugaltlink();
protected:
   DWARFDataSegment m_data_debug_aranges;
   DWARFDataSegment m_data_debug_frame;
   DWARFDataSegment m_data_debug_info;
   DWARFDataSegment m_data_debug_line;
   DWARFDataSegment m_data_debug_line_str;
   DWARFDataSegment m_data_debug_macro;
   DWARFDataSegment m_data_debug_loc;
   DWARFDataSegment m_data_debug_ranges;
+  DWARFDataSegment m_data_debug_rnglists;
   DWARFDataSegment m_data_debug_str;
   DWARFDataSegment m_data_debug_str_offsets;
   DWARFDataSegment m_data_debug_types;
   DWARFDataSegment m_data_apple_names;
   DWARFDataSegment m_data_apple_types;
   DWARFDataSegment m_data_apple_namespaces;
   DWARFDataSegment m_data_apple_objc;
   DWARFDataSegment m_data_gnu_debugaltlink;

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

 SymbolFileDWARF::SymbolFileDWARF(ObjectFile *objfile)
     : SymbolFile(objfile), UserID(uint64_t(DW_INVALID_OFFSET)
                                   << 32), // 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(NULL), m_data_debug_abbrev(),
       m_data_debug_aranges(), m_data_debug_frame(), m_data_debug_info(),
       m_data_debug_line(), m_data_debug_macro(), m_data_debug_loc(),
-      m_data_debug_ranges(), m_data_debug_str(), m_data_apple_names(),
-      m_data_apple_types(), m_data_apple_namespaces(), m_abbr(), m_info(),
-      m_line(), m_fetched_external_modules(false),
+      m_data_debug_ranges(), m_data_debug_rnglists(), m_data_debug_str(),
+      m_data_apple_names(), m_data_apple_types(), m_data_apple_namespaces(),
+      m_abbr(), m_info(), m_line(), m_fetched_external_modules(false),
       m_supports_DW_AT_APPLE_objc_complete_type(eLazyBoolCalculate), m_ranges(),
       m_unique_ast_type_map() {}
 
 SymbolFileDWARF::~SymbolFileDWARF() {}
 
 static const ConstString &GetDWARFMachOSegmentName() {
   static ConstString g_dwarf_section_name("__DWARF");
   return g_dwarf_section_name;
const DWARFDataExtractor &SymbolFileDWARF::get_debug_loc_data() {
   return GetCachedSectionData(eSectionTypeDWARFDebugLoc, m_data_debug_loc);
 }
 
 const DWARFDataExtractor &SymbolFileDWARF::get_debug_ranges_data() {
   return GetCachedSectionData(eSectionTypeDWARFDebugRanges,
                               m_data_debug_ranges);
 }
 
+const DWARFDataExtractor &SymbolFileDWARF::get_debug_rnglists_data() {
+  return GetCachedSectionData(eSectionTypeDWARFDebugRngLists,
+                              m_data_debug_rnglists);
+}
+
 const DWARFDataExtractor &SymbolFileDWARF::get_debug_str_data() {
   return GetCachedSectionData(eSectionTypeDWARFDebugStr, m_data_debug_str);
 }
 
 const DWARFDataExtractor &SymbolFileDWARF::get_debug_str_offsets_data() {
   return GetCachedSectionData(eSectionTypeDWARFDebugStrOffsets,
                               m_data_debug_str_offsets);
 }
SymbolFileDWARF::GetDWARFCompileUnit(lldb_private::CompileUnit *comp_unit) {
   return NULL;
 }
 
 DWARFDebugRanges *SymbolFileDWARF::DebugRanges() {
   if (m_ranges.get() == NULL) {
     static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
     Timer scoped_timer(func_cat, "%s this = %p", LLVM_PRETTY_FUNCTION,
                        static_cast<void *>(this));
-    if (get_debug_ranges_data().GetByteSize() > 0) {
+
+    if (get_debug_ranges_data().GetByteSize() > 0)
       m_ranges.reset(new DWARFDebugRanges());
-      if (m_ranges.get())
-        m_ranges->Extract(this);
-    }
-  }
+    else if (get_debug_rnglists_data().GetByteSize() > 0)
+      m_ranges.reset(new DWARFDebugRngLists());
+
   return m_ranges.get();
 }
 
 const DWARFDebugRanges *SymbolFileDWARF::DebugRanges() const {
   return m_ranges.get();
 }
 
 lldb::CompUnitSP SymbolFileDWARF::ParseCompileUnit(DWARFUnit *dwarf_cu,

lldb/trunk/source/Symbol/ObjectFile.cpp

if (symbol) {
           case eSectionTypeDWARFDebugLineStr:
           case eSectionTypeDWARFDebugLoc:
           case eSectionTypeDWARFDebugMacInfo:
           case eSectionTypeDWARFDebugMacro:
           case eSectionTypeDWARFDebugNames:
           case eSectionTypeDWARFDebugPubNames:
           case eSectionTypeDWARFDebugPubTypes:
           case eSectionTypeDWARFDebugRanges:
+          case eSectionTypeDWARFDebugRngLists:
           case eSectionTypeDWARFDebugStr:
           case eSectionTypeDWARFDebugStrOffsets:
           case eSectionTypeDWARFDebugTypes:
           case eSectionTypeDWARFAppleNames:
           case eSectionTypeDWARFAppleTypes:
           case eSectionTypeDWARFAppleNamespaces:
           case eSectionTypeDWARFAppleObjC:
           case eSectionTypeDWARFGNUDebugAltLink: