C++ DWARFDebugInfoEntry::GetAttributeValueAsUnsigned方法代码示例

//----------------------------------------------------------------------
// ParseCompileUnitDIEsIfNeeded
//
// Parses a compile unit and indexes its DIEs if it hasn't already been
// done.
//----------------------------------------------------------------------
size_t
DWARFCompileUnit::ExtractDIEsIfNeeded (bool cu_die_only)
{
    const size_t initial_die_array_size = m_die_array.size();
    if ((cu_die_only && initial_die_array_size > 0) || initial_die_array_size > 1)
        return 0; // Already parsed

    Timer scoped_timer (__PRETTY_FUNCTION__,
                        "%8.8x: DWARFCompileUnit::ExtractDIEsIfNeeded( cu_die_only = %i )",
                        m_offset,
                        cu_die_only);

    // 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
    if (!cu_die_only)
    {
        Log *log (LogChannelDWARF::GetLogIfAny(DWARF_LOG_DEBUG_INFO | DWARF_LOG_LOOKUPS));
        if (log)
        {
            m_dwarf2Data->GetObjectFile()->GetModule()->LogMessageVerboseBacktrace (log,
                    "DWARFCompileUnit::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& debug_info_data = m_dwarf2Data->get_debug_info_data();
    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(), m_is_dwarf64);
    while (offset < next_cu_offset &&
            die.FastExtract (debug_info_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)
        {
            uint64_t base_addr = die.GetAttributeValueAsUnsigned(m_dwarf2Data, this, DW_AT_low_pc, LLDB_INVALID_ADDRESS);
            if (base_addr == LLDB_INVALID_ADDRESS)
                base_addr = die.GetAttributeValueAsUnsigned(m_dwarf2Data, this, DW_AT_entry_pc, 0);
            SetBaseAddress (base_addr);
            if (initial_die_array_size == 0)
                AddDIE (die);
            if (cu_die_only)
                return 1;
        }
        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();
//.........这里部分代码省略.........

// m_die_array_mutex must be already held as read/write.
void DWARFUnit::AddUnitDIE(const DWARFDebugInfoEntry &cu_die) {
  dw_addr_t addr_base = cu_die.GetAttributeValueAsUnsigned(
      m_dwarf, this, DW_AT_addr_base, LLDB_INVALID_ADDRESS);
  if (addr_base != LLDB_INVALID_ADDRESS)
    SetAddrBase(addr_base);

  dw_addr_t ranges_base = cu_die.GetAttributeValueAsUnsigned(
      m_dwarf, this, DW_AT_rnglists_base, LLDB_INVALID_ADDRESS);
  if (ranges_base != LLDB_INVALID_ADDRESS)
    SetRangesBase(ranges_base);

  SetStrOffsetsBase(cu_die.GetAttributeValueAsUnsigned(
      m_dwarf, this, DW_AT_str_offsets_base, 0));

  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);

  // Here for DWO CU we want to use the address base set in the skeleton unit
  // (DW_AT_addr_base) if it is available and use the DW_AT_GNU_addr_base
  // otherwise. We do that because pre-DWARF v5 could use the DW_AT_GNU_*
  // attributes which were applicable to the DWO units. The corresponding
  // DW_AT_* attributes standardized in DWARF v5 are also applicable to the main
  // unit in contrast.
  if (addr_base == LLDB_INVALID_ADDRESS)
    addr_base = cu_die.GetAttributeValueAsUnsigned(m_dwarf, this,
                                                   DW_AT_GNU_addr_base, 0);
  dwo_cu->SetAddrBase(addr_base);

  if (ranges_base == LLDB_INVALID_ADDRESS)
    ranges_base = cu_die.GetAttributeValueAsUnsigned(m_dwarf, this,
                                                     DW_AT_GNU_ranges_base, 0);
  dwo_cu->SetRangesBase(ranges_base);

  dwo_cu->SetBaseObjOffset(m_offset);

  SetDwoStrOffsetsBase(dwo_cu);
}