Пример #1
0
//----------------------------------------------------------------------
// 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(
      LLVM_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) {
      if (initial_die_array_size == 0)
        AddCompileUnitDIE(die);
      uint64_t base_addr = die.GetAttributeValueAsAddress(
          m_dwarf2Data, this, DW_AT_low_pc, LLDB_INVALID_ADDRESS);
      if (base_addr == LLDB_INVALID_ADDRESS)
        base_addr = die.GetAttributeValueAsAddress(m_dwarf2Data, this,
                                                   DW_AT_entry_pc, 0);
      SetBaseAddress(base_addr);
      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();

      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;
    }
  }

  // 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 > next_cu_offset) {
    m_dwarf2Data->GetObjectFile()->GetModule()->ReportWarning(
        "DWARF compile unit extends beyond its bounds cu 0x%8.8x at "
        "0x%8.8" PRIx64 "\n",
        GetOffset(), offset);
  }

  // Since std::vector objects will double their size, we really need to
  // make a new array with the perfect size so we don't end up wasting
  // space. So here we copy and swap to make sure we don't have any extra
  // memory taken up.

  if (m_die_array.size() < m_die_array.capacity()) {
    DWARFDebugInfoEntry::collection exact_size_die_array(m_die_array.begin(),
                                                         m_die_array.end());
    exact_size_die_array.swap(m_die_array);
  }
  Log *verbose_log(
      LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO | DWARF_LOG_VERBOSE));
  if (verbose_log) {
    StreamString strm;
    Dump(&strm);
    if (m_die_array.empty())
      strm.Printf("error: no DIE for compile unit");
    else
      m_die_array[0].Dump(m_dwarf2Data, this, strm, UINT32_MAX);
    verbose_log->PutString(strm.GetString());
  }

  if (!m_dwo_symbol_file)
    return m_die_array.size();

  DWARFCompileUnit *dwo_cu = m_dwo_symbol_file->GetCompileUnit();
  size_t dwo_die_count = dwo_cu->ExtractDIEsIfNeeded(cu_die_only);
  return m_die_array.size() + dwo_die_count -
         1; // We have 2 CU die, but we want to count it only as one
}
Пример #2
0
// 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);
}