text: //===-- DWARFUnit.cpp -------------------------------------------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #include "DWARFUnit.h"
  
  #include "lldb/Core/Module.h"
  #include "lldb/Host/StringConvert.h"
  #include "lldb/Symbol/CompileUnit.h"
  #include "lldb/Symbol/LineTable.h"
  #include "lldb/Symbol/ObjectFile.h"
  #include "lldb/Utility/LLDBAssert.h"
  #include "lldb/Utility/StreamString.h"
  #include "lldb/Utility/Timer.h"
  
  #include "DWARFDIECollection.h"
  #include "DWARFDebugAranges.h"
  #include "DWARFDebugInfo.h"
  #include "LogChannelDWARF.h"
  #include "SymbolFileDWARFDebugMap.h"
  #include "SymbolFileDWARFDwo.h"
  
  using namespace lldb;
  using namespace lldb_private;
  using namespace std;
  
  extern int g_verbose;
  
  DWARFUnit::DWARFUnit(SymbolFileDWARF *dwarf)
      : m_dwarf(dwarf), m_cancel_scopes(false) {}
  
  DWARFUnit::~DWARFUnit() {}
  
  //----------------------------------------------------------------------
  // Parses first DIE of a compile unit.
  //----------------------------------------------------------------------
  void DWARFUnit::ExtractUnitDIEIfNeeded() {
    {
      llvm::sys::ScopedReader lock(m_first_die_mutex);
      if (m_first_die)
        return; // Already parsed
    }
    llvm::sys::ScopedWriter lock(m_first_die_mutex);
    if (m_first_die)
      return; // Already parsed
  
    static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
    Timer scoped_timer(
        func_cat, "%8.8x: DWARFUnit::ExtractUnitDIEIfNeeded()", m_offset);
  
    // Set the offset to that of the first DIE and calculate the start of the
    // next compilation unit header.
    lldb::offset_t offset = GetFirstDIEOffset();
  
    // We are in our compile unit, parse starting at the offset we were told to
    // parse
    const DWARFDataExtractor &data = GetData();
    DWARFFormValue::FixedFormSizes fixed_form_sizes =
        DWARFFormValue::GetFixedFormSizesForAddressSize(GetAddressByteSize(),
                                                        IsDWARF64());
    if (offset < GetNextCompileUnitOffset() &&
        m_first_die.FastExtract(data, this, fixed_form_sizes, &offset)) {
      AddUnitDIE(m_first_die);
      return;
    }
  
    ExtractDIEsEndCheck(offset);
  }
  
  //----------------------------------------------------------------------
  // Parses a compile unit and indexes its DIEs if it hasn't already been done.
  // It will leave this compile unit extracted forever.
  //----------------------------------------------------------------------
  void DWARFUnit::ExtractDIEsIfNeeded() {
    m_cancel_scopes = true;
  
    {
      llvm::sys::ScopedReader lock(m_die_array_mutex);
      if (!m_die_array.empty())
        return; // Already parsed
    }
    llvm::sys::ScopedWriter lock(m_die_array_mutex);
    if (!m_die_array.empty())
      return; // Already parsed
  
    ExtractDIEsRWLocked();
  }
  
  //----------------------------------------------------------------------
  // Parses a compile unit and indexes its DIEs if it hasn't already been done.
  // It will clear this compile unit after returned instance gets out of scope,
  // no other ScopedExtractDIEs instance is running for this compile unit
  // and no ExtractDIEsIfNeeded() has been executed during this ScopedExtractDIEs
  // lifetime.
  //----------------------------------------------------------------------
  DWARFUnit::ScopedExtractDIEs DWARFUnit::ExtractDIEsScoped() {
    ScopedExtractDIEs scoped(this);
  
    {
      llvm::sys::ScopedReader lock(m_die_array_mutex);
      if (!m_die_array.empty())
        return scoped; // Already parsed
    }
    llvm::sys::ScopedWriter lock(m_die_array_mutex);
    if (!m_die_array.empty())
      return scoped; // Already parsed
  
    // Otherwise m_die_array would be already populated.
    lldbassert(!m_cancel_scopes);
  
    ExtractDIEsRWLocked();
    scoped.m_clear_dies = true;
    return scoped;
  }
  
  DWARFUnit::ScopedExtractDIEs::ScopedExtractDIEs(DWARFUnit *cu) : m_cu(cu) {
    lldbassert(m_cu);
    m_cu->m_die_array_scoped_mutex.lock_shared();
  }
  
  DWARFUnit::ScopedExtractDIEs::~ScopedExtractDIEs() {
    if (!m_cu)
      return;
    m_cu->m_die_array_scoped_mutex.unlock_shared();
    if (!m_clear_dies || m_cu->m_cancel_scopes)
      return;
    // Be sure no other ScopedExtractDIEs is running anymore.
    llvm::sys::ScopedWriter lock_scoped(m_cu->m_die_array_scoped_mutex);
    llvm::sys::ScopedWriter lock(m_cu->m_die_array_mutex);
    if (m_cu->m_cancel_scopes)
      return;
    m_cu->ClearDIEsRWLocked();
  }
  
  DWARFUnit::ScopedExtractDIEs::ScopedExtractDIEs(ScopedExtractDIEs &&rhs)
      : m_cu(rhs.m_cu), m_clear_dies(rhs.m_clear_dies) {
    rhs.m_cu = nullptr;
  }
  
  DWARFUnit::ScopedExtractDIEs &DWARFUnit::ScopedExtractDIEs::operator=(
      DWARFUnit::ScopedExtractDIEs &&rhs) {
    m_cu = rhs.m_cu;
    rhs.m_cu = nullptr;
    m_clear_dies = rhs.m_clear_dies;
    return *this;
  }
  
  //----------------------------------------------------------------------
  // Parses a compile unit and indexes its DIEs, m_die_array_mutex must be
  // held R/W and m_die_array must be empty.
  //----------------------------------------------------------------------
  void DWARFUnit::ExtractDIEsRWLocked() {
    llvm::sys::ScopedWriter first_die_lock(m_first_die_mutex);
  
    static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
    Timer scoped_timer(
        func_cat, "%8.8x: DWARFUnit::ExtractDIEsIfNeeded()", m_offset);
  
    // Set the offset to that of the first DIE and calculate the start of the
    // next compilation unit header.
    lldb::offset_t offset = GetFirstDIEOffset();
    lldb::offset_t next_cu_offset = GetNextCompileUnitOffset();
  
    DWARFDebugInfoEntry die;
    // Keep a flat array of the DIE for binary lookup by DIE offset
    Log *log(
        LogChannelDWARF::GetLogIfAny(DWARF_LOG_DEBUG_INFO | DWARF_LOG_LOOKUPS));
    if (log) {
      m_dwarf->GetObjectFile()->GetModule()->LogMessageVerboseBacktrace(
          log,
          "DWARFUnit::ExtractDIEsIfNeeded () for compile unit at "
          ".debug_info[0x%8.8x]",
          GetOffset());
    }
  
    uint32_t depth = 0;
    // We are in our compile unit, parse starting at the offset we were told to
    // parse
    const DWARFDataExtractor &data = GetData();
    std::vector<uint32_t> die_index_stack;
    die_index_stack.reserve(32);
    die_index_stack.push_back(0);
    bool prev_die_had_children = false;
    DWARFFormValue::FixedFormSizes fixed_form_sizes =
        DWARFFormValue::GetFixedFormSizesForAddressSize(GetAddressByteSize(),
                                                        IsDWARF64());
    while (offset < next_cu_offset &&
           die.FastExtract(data, this, fixed_form_sizes, &offset)) {
      //        if (log)
      //            log->Printf("0x%8.8x: %*.*s%s%s",
      //                        die.GetOffset(),
      //                        depth * 2, depth * 2, "",
      //                        DW_TAG_value_to_name (die.Tag()),
      //                        die.HasChildren() ? " *" : "");
  
      const bool null_die = die.IsNULL();
      if (depth == 0) {
        assert(m_die_array.empty() && "Compile unit DIE already added");
  
        // The average bytes per DIE entry has been seen to be around 14-20 so
        // lets pre-reserve half of that since we are now stripping the NULL
        // tags.
  
        // Only reserve the memory if we are adding children of the main
        // compile unit DIE. The compile unit DIE is always the first entry, so
        // if our size is 1, then we are adding the first compile unit child
        // DIE and should reserve the memory.
        m_die_array.reserve(GetDebugInfoSize() / 24);
        m_die_array.push_back(die);
  
        if (!m_first_die)
          AddUnitDIE(m_die_array.front());
      } else {
        if (null_die) {
          if (prev_die_had_children) {
            // This will only happen if a DIE says is has children but all it
            // contains is a NULL tag. Since we are removing the NULL DIEs from
            // the list (saves up to 25% in C++ code), we need a way to let the
            // DIE know that it actually doesn't have children.
            if (!m_die_array.empty())
              m_die_array.back().SetEmptyChildren(true);
          }
        } else {
          die.SetParentIndex(m_die_array.size() - die_index_stack[depth - 1]);
  
          if (die_index_stack.back())
            m_die_array[die_index_stack.back()].SetSiblingIndex(
                m_die_array.size() - die_index_stack.back());
  
          // Only push the DIE if it isn't a NULL DIE
          m_die_array.push_back(die);
        }
      }
  
      if (null_die) {
        // NULL DIE.
        if (!die_index_stack.empty())
          die_index_stack.pop_back();
  
        if (depth > 0)
          --depth;
        if (depth == 0)
          break; // We are done with this compile unit!
  
        prev_die_had_children = false;
      } else {
        die_index_stack.back() = m_die_array.size() - 1;
        // Normal DIE
        const bool die_has_children = die.HasChildren();
        if (die_has_children) {
          die_index_stack.push_back(0);
          ++depth;
        }
        prev_die_had_children = die_has_children;
      }
    }
  
    if (!m_die_array.empty()) {
      if (m_first_die) {
        // Only needed for the assertion.
        m_first_die.SetEmptyChildren(m_die_array.front().GetEmptyChildren());
        lldbassert(m_first_die == m_die_array.front());
      }
      m_first_die = m_die_array.front();
    }
  
    m_die_array.shrink_to_fit();
  
    ExtractDIEsEndCheck(offset);
  
    if (m_dwo_symbol_file) {
      DWARFUnit *dwo_cu = m_dwo_symbol_file->GetCompileUnit();
      dwo_cu->ExtractDIEsIfNeeded();
    }
  }
  
  //--------------------------------------------------------------------------
  // Final checks for both ExtractUnitDIEIfNeeded() and ExtractDIEsIfNeeded().
  //--------------------------------------------------------------------------
  void DWARFUnit::ExtractDIEsEndCheck(lldb::offset_t offset) const {
    // Give a little bit of info if we encounter corrupt DWARF (our offset should
    // always terminate at or before the start of the next compilation unit
    // header).
    if (offset > GetNextCompileUnitOffset()) {
      m_dwarf->GetObjectFile()->GetModule()->ReportWarning(
          "DWARF compile unit extends beyond its bounds cu 0x%8.8x at "
          "0x%8.8" PRIx64 "\n",
          GetOffset(), offset);
    }
  
    Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO));
    if (log && log->GetVerbose()) {
      StreamString strm;
      Dump(&strm);
      if (m_die_array.empty())
        strm.Printf("error: no DIE for compile unit");
      else
        m_die_array[0].Dump(m_dwarf, this, strm, UINT32_MAX);
      log->PutString(strm.GetString());
    }
  }
  
  // m_die_array_mutex must be already held as read/write.
  void DWARFUnit::AddUnitDIE(const DWARFDebugInfoEntry &cu_die) {
    uint64_t base_addr = cu_die.GetAttributeValueAsAddress(
        m_dwarf, this, DW_AT_low_pc, LLDB_INVALID_ADDRESS);
    if (base_addr == LLDB_INVALID_ADDRESS)
      base_addr = cu_die.GetAttributeValueAsAddress(
          m_dwarf, this, DW_AT_entry_pc, 0);
    SetBaseAddress(base_addr);
  
    std::unique_ptr<SymbolFileDWARFDwo> dwo_symbol_file =
        m_dwarf->GetDwoSymbolFileForCompileUnit(*this, cu_die);
    if (!dwo_symbol_file)
      return;
  
    DWARFUnit *dwo_cu = dwo_symbol_file->GetCompileUnit();
    if (!dwo_cu)
      return; // Can't fetch the compile unit from the dwo file.
  
    DWARFBaseDIE dwo_cu_die = dwo_cu->GetUnitDIEOnly();
    if (!dwo_cu_die.IsValid())
      return; // Can't fetch the compile unit DIE from the dwo file.
  
    uint64_t main_dwo_id =
        cu_die.GetAttributeValueAsUnsigned(m_dwarf, this, DW_AT_GNU_dwo_id, 0);
    uint64_t sub_dwo_id =
        dwo_cu_die.GetAttributeValueAsUnsigned(DW_AT_GNU_dwo_id, 0);
    if (main_dwo_id != sub_dwo_id)
      return; // The 2 dwo ID isn't match. Don't use the dwo file as it belongs to
    // a differectn compilation.
  
    m_dwo_symbol_file = std::move(dwo_symbol_file);
  
    dw_addr_t addr_base =
        cu_die.GetAttributeValueAsUnsigned(m_dwarf, this, DW_AT_GNU_addr_base, 0);
    dw_addr_t ranges_base = cu_die.GetAttributeValueAsUnsigned(
        m_dwarf, this, DW_AT_GNU_ranges_base, 0);
    dwo_cu->SetAddrBase(addr_base, ranges_base, m_offset);
  }
  
  DWARFDIE DWARFUnit::LookupAddress(const dw_addr_t address) {
    if (DIE()) {
      const DWARFDebugAranges &func_aranges = GetFunctionAranges();
  
      // Re-check the aranges auto pointer contents in case it was created above
      if (!func_aranges.IsEmpty())
        return GetDIE(func_aranges.FindAddress(address));
    }
    return DWARFDIE();
  }
  
  size_t DWARFUnit::AppendDIEsWithTag(const dw_tag_t tag,
  				    DWARFDIECollection &dies,
  				    uint32_t depth) const {
    size_t old_size = dies.Size();
    {
      llvm::sys::ScopedReader lock(m_die_array_mutex);
      DWARFDebugInfoEntry::const_iterator pos;
      DWARFDebugInfoEntry::const_iterator end = m_die_array.end();
      for (pos = m_die_array.begin(); pos != end; ++pos) {
        if (pos->Tag() == tag)
          dies.Append(DWARFDIE(this, &(*pos)));
      }
    }
  
    // Return the number of DIEs added to the collection
    return dies.Size() - old_size;
  }
  
  
  lldb::user_id_t DWARFUnit::GetID() const {
    dw_offset_t local_id =
        m_base_obj_offset != DW_INVALID_OFFSET ? m_base_obj_offset : m_offset;
    if (m_dwarf)
      return DIERef(local_id, local_id).GetUID(m_dwarf);
    else
      return local_id;
  }
  
  dw_offset_t DWARFUnit::GetNextCompileUnitOffset() const {
    return m_offset + GetLengthByteSize() + GetLength();
  }
  
  size_t DWARFUnit::GetDebugInfoSize() const {
    return GetLengthByteSize() + GetLength() - GetHeaderByteSize();
  }
  
  const DWARFAbbreviationDeclarationSet *DWARFUnit::GetAbbreviations() const {
    return m_abbrevs;
  }
  
  dw_offset_t DWARFUnit::GetAbbrevOffset() const {
    return m_abbrevs ? m_abbrevs->GetOffset() : DW_INVALID_OFFSET;
  }
  
  void DWARFUnit::SetAddrBase(dw_addr_t addr_base,
                              dw_addr_t ranges_base,
                              dw_offset_t base_obj_offset) {
    m_addr_base = addr_base;
    m_ranges_base = ranges_base;
    m_base_obj_offset = base_obj_offset;
  }
  
  // It may be called only with m_die_array_mutex held R/W.
  void DWARFUnit::ClearDIEsRWLocked() {
    m_die_array.clear();
    m_die_array.shrink_to_fit();
  
    if (m_dwo_symbol_file)
      m_dwo_symbol_file->GetCompileUnit()->ClearDIEsRWLocked();
  }
  
  void DWARFUnit::BuildAddressRangeTable(SymbolFileDWARF *dwarf,
                                         DWARFDebugAranges *debug_aranges) {
    // This function is usually called if there in no .debug_aranges section in
    // order to produce a compile unit level set of address ranges that is
    // accurate.
  
    size_t num_debug_aranges = debug_aranges->GetNumRanges();
  
    // First get the compile unit DIE only and check if it has a DW_AT_ranges
    const DWARFDebugInfoEntry *die = GetUnitDIEPtrOnly();
  
    const dw_offset_t cu_offset = GetOffset();
    if (die) {
      DWARFRangeList ranges;
      const size_t num_ranges =
          die->GetAttributeAddressRanges(dwarf, this, ranges, false);
      if (num_ranges > 0) {
        // This compile unit has DW_AT_ranges, assume this is correct if it is
        // present since clang no longer makes .debug_aranges by default and it
        // emits DW_AT_ranges for DW_TAG_compile_units. GCC also does this with
        // recent GCC builds.
        for (size_t i = 0; i < num_ranges; ++i) {
          const DWARFRangeList::Entry &range = ranges.GetEntryRef(i);
          debug_aranges->AppendRange(cu_offset, range.GetRangeBase(),
                                     range.GetRangeEnd());
        }
  
        return; // We got all of our ranges from the DW_AT_ranges attribute
      }
    }
    // We don't have a DW_AT_ranges attribute, so we need to parse the DWARF
  
    // If the DIEs weren't parsed, then we don't want all dies for all compile
    // units to stay loaded when they weren't needed. So we can end up parsing
    // the DWARF and then throwing them all away to keep memory usage down.
    ScopedExtractDIEs clear_dies(ExtractDIEsScoped());
  
    die = DIEPtr();
    if (die)
      die->BuildAddressRangeTable(dwarf, this, debug_aranges);
  
    if (debug_aranges->GetNumRanges() == num_debug_aranges) {
      // We got nothing from the functions, maybe we have a line tables only
      // situation. Check the line tables and build the arange table from this.
      SymbolContext sc;
      sc.comp_unit = dwarf->GetCompUnitForDWARFCompUnit(this);
      if (sc.comp_unit) {
        SymbolFileDWARFDebugMap *debug_map_sym_file =
            m_dwarf->GetDebugMapSymfile();
        if (debug_map_sym_file == NULL) {
          LineTable *line_table = sc.comp_unit->GetLineTable();
  
          if (line_table) {
            LineTable::FileAddressRanges file_ranges;
            const bool append = true;
            const size_t num_ranges =
                line_table->GetContiguousFileAddressRanges(file_ranges, append);
            for (uint32_t idx = 0; idx < num_ranges; ++idx) {
              const LineTable::FileAddressRanges::Entry &range =
                  file_ranges.GetEntryRef(idx);
              debug_aranges->AppendRange(cu_offset, range.GetRangeBase(),
                                         range.GetRangeEnd());
            }
          }
        } else
          debug_map_sym_file->AddOSOARanges(dwarf, debug_aranges);
      }
    }
  
    if (debug_aranges->GetNumRanges() == num_debug_aranges) {
      // We got nothing from the functions, maybe we have a line tables only
      // situation. Check the line tables and build the arange table from this.
      SymbolContext sc;
      sc.comp_unit = dwarf->GetCompUnitForDWARFCompUnit(this);
      if (sc.comp_unit) {
        LineTable *line_table = sc.comp_unit->GetLineTable();
  
        if (line_table) {
          LineTable::FileAddressRanges file_ranges;
          const bool append = true;
          const size_t num_ranges =
              line_table->GetContiguousFileAddressRanges(file_ranges, append);
          for (uint32_t idx = 0; idx < num_ranges; ++idx) {
            const LineTable::FileAddressRanges::Entry &range =
                file_ranges.GetEntryRef(idx);
            debug_aranges->AppendRange(GetOffset(), range.GetRangeBase(),
                                       range.GetRangeEnd());
          }
        }
      }
    }
  }
  
  lldb::ByteOrder DWARFUnit::GetByteOrder() const {
    return m_dwarf->GetObjectFile()->GetByteOrder();
  }
  
  TypeSystem *DWARFUnit::GetTypeSystem() {
    if (m_dwarf)
      return m_dwarf->GetTypeSystemForLanguage(GetLanguageType());
    else
      return nullptr;
  }
  
  DWARFFormValue::FixedFormSizes DWARFUnit::GetFixedFormSizes() {
    return DWARFFormValue::GetFixedFormSizesForAddressSize(GetAddressByteSize(),
                                                           IsDWARF64());
  }
  
  void DWARFUnit::SetBaseAddress(dw_addr_t base_addr) { m_base_addr = base_addr; }
  
  //----------------------------------------------------------------------
  // Compare function DWARFDebugAranges::Range structures
  //----------------------------------------------------------------------
  static bool CompareDIEOffset(const DWARFDebugInfoEntry &die,
                               const dw_offset_t die_offset) {
    return die.GetOffset() < die_offset;
  }
  
  //----------------------------------------------------------------------
  // GetDIE()
  //
  // Get the DIE (Debug Information Entry) with the specified offset by first
  // checking if the DIE is contained within this compile unit and grabbing the
  // DIE from this compile unit. Otherwise we grab the DIE from the DWARF file.
  //----------------------------------------------------------------------
  DWARFDIE
  DWARFUnit::GetDIE(dw_offset_t die_offset) {
    if (die_offset != DW_INVALID_OFFSET) {
      if (GetDwoSymbolFile())
        return GetDwoSymbolFile()->GetCompileUnit()->GetDIE(die_offset);
  
      if (ContainsDIEOffset(die_offset)) {
        ExtractDIEsIfNeeded();
        DWARFDebugInfoEntry::const_iterator end = m_die_array.cend();
        DWARFDebugInfoEntry::const_iterator pos =
            lower_bound(m_die_array.cbegin(), end, die_offset, CompareDIEOffset);
        if (pos != end) {
          if (die_offset == (*pos).GetOffset())
            return DWARFDIE(this, &(*pos));
        }
      } else {
        // Don't specify the compile unit offset as we don't know it because the
        // DIE belongs to
        // a different compile unit in the same symbol file.
        return m_dwarf->DebugInfo()->GetDIEForDIEOffset(die_offset);
      }
    }
    return DWARFDIE(); // Not found
  }
  
  uint8_t DWARFUnit::GetAddressByteSize(const DWARFUnit *cu) {
    if (cu)
      return cu->GetAddressByteSize();
    return DWARFUnit::GetDefaultAddressSize();
  }
  
  bool DWARFUnit::IsDWARF64(const DWARFUnit *cu) {
    if (cu)
      return cu->IsDWARF64();
    return false;
  }
  
  uint8_t DWARFUnit::GetDefaultAddressSize() { return 4; }
  
  void *DWARFUnit::GetUserData() const { return m_user_data; }
  
  void DWARFUnit::SetUserData(void *d) {
    m_user_data = d;
    if (m_dwo_symbol_file)
      m_dwo_symbol_file->GetCompileUnit()->SetUserData(d);
  }
  
  bool DWARFUnit::Supports_DW_AT_APPLE_objc_complete_type() {
    if (GetProducer() == eProducerLLVMGCC)
      return false;
    return true;
  }
  
  bool DWARFUnit::DW_AT_decl_file_attributes_are_invalid() {
    // llvm-gcc makes completely invalid decl file attributes and won't ever be
    // fixed, so we need to know to ignore these.
    return GetProducer() == eProducerLLVMGCC;
  }
  
  bool DWARFUnit::Supports_unnamed_objc_bitfields() {
    if (GetProducer() == eProducerClang) {
      const uint32_t major_version = GetProducerVersionMajor();
      if (major_version > 425 ||
          (major_version == 425 && GetProducerVersionUpdate() >= 13))
        return true;
      else
        return false;
    }
    return true; // Assume all other compilers didn't have incorrect ObjC bitfield
                 // info
  }
  
  SymbolFileDWARF *DWARFUnit::GetSymbolFileDWARF() const { return m_dwarf; }
  
  void DWARFUnit::ParseProducerInfo() {
    m_producer_version_major = UINT32_MAX;
    m_producer_version_minor = UINT32_MAX;
    m_producer_version_update = UINT32_MAX;
  
    const DWARFDebugInfoEntry *die = GetUnitDIEPtrOnly();
    if (die) {
  
      const char *producer_cstr =
          die->GetAttributeValueAsString(m_dwarf, this, DW_AT_producer, NULL);
      if (producer_cstr) {
        RegularExpression llvm_gcc_regex(
            llvm::StringRef("^4\\.[012]\\.[01] \\(Based on Apple "
                            "Inc\\. build [0-9]+\\) \\(LLVM build "
                            "[\\.0-9]+\\)$"));
        if (llvm_gcc_regex.Execute(llvm::StringRef(producer_cstr))) {
          m_producer = eProducerLLVMGCC;
        } else if (strstr(producer_cstr, "clang")) {
          static RegularExpression g_clang_version_regex(
              llvm::StringRef("clang-([0-9]+)\\.([0-9]+)\\.([0-9]+)"));
          RegularExpression::Match regex_match(3);
          if (g_clang_version_regex.Execute(llvm::StringRef(producer_cstr),
                                            &regex_match)) {
            std::string str;
            if (regex_match.GetMatchAtIndex(producer_cstr, 1, str))
              m_producer_version_major =
                  StringConvert::ToUInt32(str.c_str(), UINT32_MAX, 10);
            if (regex_match.GetMatchAtIndex(producer_cstr, 2, str))
              m_producer_version_minor =
                  StringConvert::ToUInt32(str.c_str(), UINT32_MAX, 10);
            if (regex_match.GetMatchAtIndex(producer_cstr, 3, str))
              m_producer_version_update =
                  StringConvert::ToUInt32(str.c_str(), UINT32_MAX, 10);
          }
          m_producer = eProducerClang;
        } else if (strstr(producer_cstr, "GNU"))
          m_producer = eProducerGCC;
      }
    }
    if (m_producer == eProducerInvalid)
      m_producer = eProcucerOther;
  }
  
  DWARFProducer DWARFUnit::GetProducer() {
    if (m_producer == eProducerInvalid)
      ParseProducerInfo();
    return m_producer;
  }
  
  uint32_t DWARFUnit::GetProducerVersionMajor() {
    if (m_producer_version_major == 0)
      ParseProducerInfo();
    return m_producer_version_major;
  }
  
  uint32_t DWARFUnit::GetProducerVersionMinor() {
    if (m_producer_version_minor == 0)
      ParseProducerInfo();
    return m_producer_version_minor;
  }
  
  uint32_t DWARFUnit::GetProducerVersionUpdate() {
    if (m_producer_version_update == 0)
      ParseProducerInfo();
    return m_producer_version_update;
  }
  LanguageType DWARFUnit::LanguageTypeFromDWARF(uint64_t val) {
    // Note: user languages between lo_user and hi_user must be handled
    // explicitly here.
    switch (val) {
    case DW_LANG_Mips_Assembler:
      return eLanguageTypeMipsAssembler;
    case DW_LANG_GOOGLE_RenderScript:
      return eLanguageTypeExtRenderScript;
    default:
      return static_cast<LanguageType>(val);
    }
  }
  
  LanguageType DWARFUnit::GetLanguageType() {
    if (m_language_type != eLanguageTypeUnknown)
      return m_language_type;
  
    const DWARFDebugInfoEntry *die = GetUnitDIEPtrOnly();
    if (die)
      m_language_type = LanguageTypeFromDWARF(
          die->GetAttributeValueAsUnsigned(m_dwarf, this, DW_AT_language, 0));
    return m_language_type;
  }
  
  bool DWARFUnit::GetIsOptimized() {
    if (m_is_optimized == eLazyBoolCalculate) {
      const DWARFDebugInfoEntry *die = GetUnitDIEPtrOnly();
      if (die) {
        m_is_optimized = eLazyBoolNo;
        if (die->GetAttributeValueAsUnsigned(m_dwarf, this, DW_AT_APPLE_optimized,
                                             0) == 1) {
          m_is_optimized = eLazyBoolYes;
        }
      }
    }
    return m_is_optimized == eLazyBoolYes;
  }
  
  SymbolFileDWARFDwo *DWARFUnit::GetDwoSymbolFile() const {
    return m_dwo_symbol_file.get();
  }
  
  dw_offset_t DWARFUnit::GetBaseObjOffset() const { return m_base_obj_offset; }
  
  const DWARFDebugAranges &DWARFUnit::GetFunctionAranges() {
    if (m_func_aranges_ap.get() == NULL) {
      m_func_aranges_ap.reset(new DWARFDebugAranges());
      Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_ARANGES));
  
      if (log) {
        m_dwarf->GetObjectFile()->GetModule()->LogMessage(
            log,
            "DWARFUnit::GetFunctionAranges() for compile unit at "
            ".debug_info[0x%8.8x]",
            GetOffset());
      }
      const DWARFDebugInfoEntry *die = DIEPtr();
      if (die)
        die->BuildFunctionAddressRangeTable(m_dwarf, this,
                                            m_func_aranges_ap.get());
  
      if (m_dwo_symbol_file) {
        DWARFUnit *dwo_cu = m_dwo_symbol_file->GetCompileUnit();
        const DWARFDebugInfoEntry *dwo_die = dwo_cu->DIEPtr();
        if (dwo_die)
          dwo_die->BuildFunctionAddressRangeTable(m_dwo_symbol_file.get(), dwo_cu,
                                                  m_func_aranges_ap.get());
      }
  
      const bool minimize = false;
      m_func_aranges_ap->Sort(minimize);
    }
    return *m_func_aranges_ap.get();
  }
  
  