C++ DWARFDebugInfoEntry类代码示例

void DWARFUnit::extractDIEsToVector(
    bool AppendCUDie, bool AppendNonCUDies,
    std::vector<DWARFDebugInfoEntry> &Dies) const {
  if (!AppendCUDie && !AppendNonCUDies)
    return;

  // Set the offset to that of the first DIE and calculate the start of the
  // next compilation unit header.
  uint32_t DIEOffset = getOffset() + getHeaderSize();
  uint32_t NextCUOffset = getNextUnitOffset();
  DWARFDebugInfoEntry DIE;
  DWARFDataExtractor DebugInfoData = getDebugInfoExtractor();
  uint32_t Depth = 0;
  bool IsCUDie = true;

  while (DIE.extractFast(*this, &DIEOffset, DebugInfoData, NextCUOffset,
                         Depth)) {
    if (IsCUDie) {
      if (AppendCUDie)
        Dies.push_back(DIE);
      if (!AppendNonCUDies)
        break;
      // The average bytes per DIE entry has been seen to be
      // around 14-20 so let's pre-reserve the needed memory for
      // our DIE entries accordingly.
      Dies.reserve(Dies.size() + getDebugInfoSize() / 14);
      IsCUDie = false;
    } else {
      Dies.push_back(DIE);
    }

    if (const DWARFAbbreviationDeclaration *AbbrDecl =
            DIE.getAbbreviationDeclarationPtr()) {
      // Normal DIE
      if (AbbrDecl->hasChildren())
        ++Depth;
    } else {
      // NULL DIE.
      if (Depth > 0)
        --Depth;
      if (Depth == 0)
        break;  // We are done with this compile unit!
    }
  }

  // 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 (DIEOffset > NextCUOffset)
    WithColor::warning() << format("DWARF compile unit extends beyond its "
                                   "bounds cu 0x%8.8x at 0x%8.8x\n",
                                   getOffset(), DIEOffset);
}

//----------------------------------------------------------------------
// Parse
//
// Parses the .debug_info section and uses the .debug_abbrev section
// and various other sections in the SymbolFileDWARF class and calls the
// supplied callback function each time a compile unit header, or debug
// information entry is successfully parsed. This function can be used
// for different tasks such as parsing the file contents into a
// structured data, dumping, verifying and much more.
//----------------------------------------------------------------------
void DWARFDebugInfo::Parse(SymbolFileDWARF *dwarf2Data, Callback callback,
                           void *userData) {
  if (dwarf2Data) {
    lldb::offset_t offset = 0;
    uint32_t depth = 0;
    DWARFDebugInfoEntry die;

    DWARFCompileUnitSP cu;
    while ((cu = DWARFCompileUnit::Extract(dwarf2Data, &offset))) {
      const dw_offset_t next_cu_offset = cu->GetNextCompileUnitOffset();

      depth = 0;
      // Call the callback function with no DIE pointer for the compile unit
      // and get the offset that we are to continue to parse from
      offset = callback(dwarf2Data, cu.get(), NULL, offset, depth, userData);

      // Make sure we are within our compile unit
      if (offset < next_cu_offset) {
        // We are in our compile unit, parse starting at the offset
        // we were told to parse
        bool done = false;
        while (!done && die.Extract(dwarf2Data, cu.get(), &offset)) {
          // Call the callback function with DIE pointer that falls within the
          // compile unit
          offset =
              callback(dwarf2Data, cu.get(), &die, offset, depth, userData);

          if (die.IsNULL()) {
            if (depth)
              --depth;
            else
              done = true; // We are done with this compile unit!
          } else if (die.HasChildren())
            ++depth;
        }
      }

      // Make sure the offset returned is valid, and if not stop parsing.
      // Returning DW_INVALID_OFFSET from this callback is a good way to end
      // all parsing
      if (!dwarf2Data->get_debug_info_data().ValidOffset(offset))
        break;

      // Make sure we start on a proper
      offset = next_cu_offset;
    }
  }
}

bool
DWARFCompileUnit::LookupAddress
(
    const dw_addr_t address,
    DWARFDebugInfoEntry** function_die_handle,
    DWARFDebugInfoEntry** block_die_handle
)
{
    bool success = false;

    if (function_die_handle != NULL && DIE())
    {

        const DWARFDebugAranges &func_aranges = GetFunctionAranges ();

        // Re-check the aranges auto pointer contents in case it was created above
        if (!func_aranges.IsEmpty())
        {
            *function_die_handle = GetDIEPtr(func_aranges.FindAddress(address));
            if (*function_die_handle != NULL)
            {
                success = true;
                if (block_die_handle != NULL)
                {
                    DWARFDebugInfoEntry* child = (*function_die_handle)->GetFirstChild();
                    while (child)
                    {
                        if (child->LookupAddress(address, m_dwarf2Data, this, NULL, block_die_handle))
                            break;
                        child = child->GetSibling();
                    }
                }
            }
        }
    }
    return success;
}

//----------------------------------------------------------------------
// Compare function DWARFDebugAranges::Range structures
//----------------------------------------------------------------------
static bool CompareDIEOffset (const DWARFDebugInfoEntry& die, const dw_offset_t die_offset)
{
    return die.GetOffset() < die_offset;
}

//----------------------------------------------------------------------
// 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.........

//----------------------------------------------------------------------
// Parse
//
// Parses the .debug_info section and uses the .debug_abbrev section
// and various other sections in the SymbolFileDWARF class and calls the
// supplied callback function each time a compile unit header, or debug
// information entry is successfully parsed. This function can be used
// for different tasks such as parsing the file contents into a
// structured data, dumping, verifying and much more.
//----------------------------------------------------------------------
void
DWARFDebugInfo::Parse(SymbolFileDWARF* dwarf2Data, Callback callback, void* userData)
{
    if (dwarf2Data)
    {
        lldb::offset_t offset = 0;
        uint32_t depth = 0;
        DWARFCompileUnitSP cu(new DWARFCompileUnit(dwarf2Data));
        if (cu.get() == NULL)
            return;
        DWARFDebugInfoEntry die;

        while (cu->Extract(dwarf2Data->get_debug_info_data(), &offset))
        {
            const dw_offset_t next_cu_offset = cu->GetNextCompileUnitOffset();

            depth = 0;
            // Call the callback function with no DIE pointer for the compile unit
            // and get the offset that we are to continue to parse from
            offset = callback(dwarf2Data, cu.get(), NULL, offset, depth, userData);

            // Make sure we are within our compile unit
            if (offset < next_cu_offset)
            {
                // We are in our compile unit, parse starting at the offset
                // we were told to parse
                bool done = false;
                while (!done && die.Extract(dwarf2Data, cu.get(), &offset))
                {
                    // Call the callback function with DIE pointer that falls within the compile unit
                    offset = callback(dwarf2Data, cu.get(), &die, offset, depth, userData);

                    if (die.IsNULL())
                    {
                        if (depth)
                            --depth;
                        else
                            done = true;    // We are done with this compile unit!
                    }
                    else if (die.HasChildren())
                        ++depth;
                }
            }

            // Make sure the offset returned is valid, and if not stop parsing.
            // Returning DW_INVALID_OFFSET from this callback is a good way to end
            // all parsing
            if (!dwarf2Data->get_debug_info_data().ValidOffset(offset))
                break;

            // See if during the callback anyone retained a copy of the compile
            // unit other than ourselves and if so, let whomever did own the object
            // and create a new one for our own use!
            if (!cu.unique())
                cu.reset(new DWARFCompileUnit(dwarf2Data));


            // Make sure we start on a proper
            offset = next_cu_offset;
        }
    }
}

//----------------------------------------------------------------------
// Compare function DWARFDebugAranges::Range structures
//----------------------------------------------------------------------
static bool CompareDIEOffset (const DWARFDebugInfoEntry& die1, const DWARFDebugInfoEntry& die2)
{
    return die1.GetOffset() < die2.GetOffset();
}

// 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);
}

// 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;

  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());
  while (offset < next_cu_offset &&
         die.FastExtract(data, this, fixed_form_sizes, &offset)) {
    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().SetHasChildren(false);
        }
      } 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;
      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 (depth == 0)
      break; // We are done with this compile unit!
  }

  if (!m_die_array.empty()) {
    if (m_first_die) {
      // Only needed for the assertion.
      m_first_die.SetHasChildren(m_die_array.front().HasChildren());
      lldbassert(m_first_die == m_die_array.front());
    }
    m_first_die = m_die_array.front();
  }

  m_die_array.shrink_to_fit();
//.........这里部分代码省略.........