C++ DWARFDataExtractor::GetU8方法代码示例

void DWARFDebugMacroHeader::SkipOperandTable(
    const DWARFDataExtractor &debug_macro_data, lldb::offset_t *offset) {
  uint8_t entry_count = debug_macro_data.GetU8(offset);
  for (uint8_t i = 0; i < entry_count; i++) {
    // Skip over the opcode number.
    debug_macro_data.GetU8(offset);

    uint64_t operand_count = debug_macro_data.GetULEB128(offset);

    for (uint64_t j = 0; j < operand_count; j++) {
      // Skip over the operand form
      debug_macro_data.GetU8(offset);
    }
  }
}

bool
DWARFCompileUnit::Extract(const DWARFDataExtractor &debug_info, lldb::offset_t *offset_ptr)
{
    Clear();

    m_offset = *offset_ptr;

    if (debug_info.ValidOffset(*offset_ptr))
    {
        dw_offset_t abbr_offset;
        const DWARFDebugAbbrev *abbr = m_dwarf2Data->DebugAbbrev();
        m_length        = debug_info.GetDWARFInitialLength(offset_ptr);
        m_is_dwarf64    = debug_info.IsDWARF64();
        m_version       = debug_info.GetU16(offset_ptr);
        abbr_offset     = debug_info.GetDWARFOffset(offset_ptr);
        m_addr_size     = debug_info.GetU8 (offset_ptr);

        bool length_OK = debug_info.ValidOffset(GetNextCompileUnitOffset()-1);
        bool version_OK = SymbolFileDWARF::SupportedVersion(m_version);
        bool abbr_offset_OK = m_dwarf2Data->get_debug_abbrev_data().ValidOffset(abbr_offset);
        bool addr_size_OK = ((m_addr_size == 4) || (m_addr_size == 8));

        if (length_OK && version_OK && addr_size_OK && abbr_offset_OK && abbr != NULL)
        {
            m_abbrevs = abbr->GetAbbreviationDeclarationSet(abbr_offset);
            return true;
        }

        // reset the offset to where we tried to parse from if anything went wrong
        *offset_ptr = m_offset;
    }

    return false;
}

bool
DWARFAbbreviationDeclaration::Extract(const DWARFDataExtractor& data, lldb::offset_t *offset_ptr, dw_uleb128_t code)
{
    m_code = code;
    m_attributes.clear();
    if (m_code)
    {
        m_tag = data.GetULEB128(offset_ptr);
        m_has_children = data.GetU8(offset_ptr);

        while (data.ValidOffset(*offset_ptr))
        {
            dw_attr_t attr = data.GetULEB128(offset_ptr);
            dw_form_t form = data.GetULEB128(offset_ptr);

            if (attr && form)
                m_attributes.push_back(DWARFAttribute(attr, form));
            else
                break;
        }

        return m_tag != 0;
    }
    else
    {
        m_tag = 0;
        m_has_children = 0;
    }

    return false;
}

bool
DWARFFormValue::SkipValue(dw_form_t form, const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr, const DWARFCompileUnit* cu)
{
    uint8_t ref_addr_size;
    switch (form)
    {
    // Blocks if inlined data that have a length field and the data bytes
    // inlined in the .debug_info
    case DW_FORM_exprloc:
    case DW_FORM_block:  { dw_uleb128_t size = debug_info_data.GetULEB128(offset_ptr); *offset_ptr += size; } return true;
    case DW_FORM_block1: { dw_uleb128_t size = debug_info_data.GetU8(offset_ptr);      *offset_ptr += size; } return true;
    case DW_FORM_block2: { dw_uleb128_t size = debug_info_data.GetU16(offset_ptr);     *offset_ptr += size; } return true;
    case DW_FORM_block4: { dw_uleb128_t size = debug_info_data.GetU32(offset_ptr);     *offset_ptr += size; } return true;

    // Inlined NULL terminated C-strings
    case DW_FORM_string:
        debug_info_data.GetCStr(offset_ptr);
        return true;

    // Compile unit address sized values
    case DW_FORM_addr:
        *offset_ptr += DWARFCompileUnit::GetAddressByteSize(cu);
        return true;

    case DW_FORM_ref_addr:
        ref_addr_size = 4;
        if (cu) {
            if (cu->GetVersion() <= 2)
                ref_addr_size = cu->GetAddressByteSize();
            else
                ref_addr_size = cu->IsDWARF64() ? 8 : 4;
        }
        *offset_ptr += ref_addr_size;
        return true;

    // 0 bytes values (implied from DW_FORM)
    case DW_FORM_flag_present:
        return true;

    // 1 byte values
    case DW_FORM_data1:
    case DW_FORM_flag:
    case DW_FORM_ref1:
        *offset_ptr += 1;
        return true;

    // 2 byte values
    case DW_FORM_data2:
    case DW_FORM_ref2:
        *offset_ptr += 2;
        return true;

    // 32 bit for DWARF 32, 64 for DWARF 64
    case DW_FORM_sec_offset:
    case DW_FORM_strp:
        *offset_ptr += (cu->IsDWARF64() ? 8 : 4);
        return true;

    // 4 byte values
    case DW_FORM_data4:
    case DW_FORM_ref4:
        *offset_ptr += 4;
        return true;

    // 8 byte values
    case DW_FORM_data8:
    case DW_FORM_ref8:
    case DW_FORM_ref_sig8:
        *offset_ptr += 8;
        return true;

    // signed or unsigned LEB 128 values
    case DW_FORM_sdata:
    case DW_FORM_udata:
    case DW_FORM_ref_udata:
        debug_info_data.Skip_LEB128(offset_ptr);
        return true;

    case DW_FORM_indirect:
        {
            dw_form_t indirect_form = debug_info_data.GetULEB128(offset_ptr);
            return DWARFFormValue::SkipValue (indirect_form,
                                              debug_info_data,
                                              offset_ptr,
                                              cu);
        }

    default:
        break;
    }
    return false;
}

bool
DWARFFormValue::ExtractValue(const DWARFDataExtractor& data, lldb::offset_t* offset_ptr, const DWARFCompileUnit* cu)
{
    bool indirect = false;
    bool is_block = false;
    m_value.data = NULL;
    uint8_t ref_addr_size;
    // Read the value for the form into value and follow and DW_FORM_indirect instances we run into
    do
    {
        indirect = false;
        switch (m_form)
        {
        case DW_FORM_addr:      m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::GetAddressByteSize(cu));  break;
        case DW_FORM_block2:    m_value.value.uval = data.GetU16(offset_ptr); is_block = true;          break;
        case DW_FORM_block4:    m_value.value.uval = data.GetU32(offset_ptr); is_block = true;          break;
        case DW_FORM_data2:     m_value.value.uval = data.GetU16(offset_ptr);                           break;
        case DW_FORM_data4:     m_value.value.uval = data.GetU32(offset_ptr);                           break;
        case DW_FORM_data8:     m_value.value.uval = data.GetU64(offset_ptr);                           break;
        case DW_FORM_string:    m_value.value.cstr = data.GetCStr(offset_ptr);
                                // Set the string value to also be the data for inlined cstr form values only
                                // so we can tell the difference between DW_FORM_string and DW_FORM_strp form
                                // values;
                                m_value.data = (uint8_t*)m_value.value.cstr;                            break;
        case DW_FORM_exprloc:
        case DW_FORM_block:     m_value.value.uval = data.GetULEB128(offset_ptr); is_block = true;      break;
        case DW_FORM_block1:    m_value.value.uval = data.GetU8(offset_ptr); is_block = true;           break;
        case DW_FORM_data1:     m_value.value.uval = data.GetU8(offset_ptr);                            break;
        case DW_FORM_flag:      m_value.value.uval = data.GetU8(offset_ptr);                            break;
        case DW_FORM_sdata:     m_value.value.sval = data.GetSLEB128(offset_ptr);                       break;
        case DW_FORM_strp:      m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(cu) ? 8 : 4);  break;
    //  case DW_FORM_APPLE_db_str:
        case DW_FORM_udata:     m_value.value.uval = data.GetULEB128(offset_ptr);                       break;
        case DW_FORM_ref_addr:  ref_addr_size = 4;
                                if (cu) {
                                    if (cu->GetVersion() <= 2)
                                        ref_addr_size = cu->GetAddressByteSize();
                                    else
                                        ref_addr_size = cu->IsDWARF64() ? 8 : 4;
                                }
                                m_value.value.uval = data.GetMaxU64(offset_ptr, ref_addr_size);         break;
        case DW_FORM_ref1:      m_value.value.uval = data.GetU8(offset_ptr);                            break;
        case DW_FORM_ref2:      m_value.value.uval = data.GetU16(offset_ptr);                           break;
        case DW_FORM_ref4:      m_value.value.uval = data.GetU32(offset_ptr);                           break;
        case DW_FORM_ref8:      m_value.value.uval = data.GetU64(offset_ptr);                           break;
        case DW_FORM_ref_udata: m_value.value.uval = data.GetULEB128(offset_ptr);                       break;
        case DW_FORM_indirect:
            m_form = data.GetULEB128(offset_ptr);
            indirect = true;
            break;

        case DW_FORM_sec_offset:    m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(cu) ? 8 : 4);  break;
        case DW_FORM_flag_present:  m_value.value.uval = 1;                                             break;
        case DW_FORM_ref_sig8:      m_value.value.uval = data.GetU64(offset_ptr);                       break;
        default:
            return false;
            break;
        }
    } while (indirect);

    if (is_block)
    {
        m_value.data = data.PeekData(*offset_ptr, m_value.value.uval);
        if (m_value.data != NULL)
        {
            *offset_ptr += m_value.value.uval;
        }
    }

    return true;
}

void DWARFDebugMacroEntry::ReadMacroEntries(
    const DWARFDataExtractor &debug_macro_data,
    const DWARFDataExtractor &debug_str_data, const bool offset_is_64_bit,
    lldb::offset_t *offset, SymbolFileDWARF *sym_file_dwarf,
    DebugMacrosSP &debug_macros_sp) {
#if TODO_REQUIRES_LLVM_ORG_SYNC
  // This code can go back in once llvm.org macros support is in the relevant
  // GitHub llvm branch.
  llvm::dwarf::MacroEntryType type =
      static_cast<llvm::dwarf::MacroEntryType>(debug_macro_data.GetU8(offset));
  while (type != 0) {
    lldb::offset_t new_offset = 0, str_offset = 0;
    uint32_t line = 0;
    const char *macro_str = nullptr;
    uint32_t debug_line_file_idx = 0;

    switch (type) {
    case DW_MACRO_define:
    case DW_MACRO_undef:
      line = debug_macro_data.GetULEB128(offset);
      macro_str = debug_macro_data.GetCStr(offset);
      if (type == DW_MACRO_define)
        debug_macros_sp->AddMacroEntry(
            DebugMacroEntry::CreateDefineEntry(line, macro_str));
      else
        debug_macros_sp->AddMacroEntry(
            DebugMacroEntry::CreateUndefEntry(line, macro_str));
      break;
    case DW_MACRO_define_indirect:
    case DW_MACRO_undef_indirect:
      line = debug_macro_data.GetULEB128(offset);
      if (offset_is_64_bit)
        str_offset = debug_macro_data.GetU64(offset);
      else
        str_offset = debug_macro_data.GetU32(offset);
      macro_str = debug_str_data.GetCStr(&str_offset);
      if (type == DW_MACRO_define_indirect)
        debug_macros_sp->AddMacroEntry(
            DebugMacroEntry::CreateDefineEntry(line, macro_str));
      else
        debug_macros_sp->AddMacroEntry(
            DebugMacroEntry::CreateUndefEntry(line, macro_str));
      break;
    case DW_MACRO_start_file:
      line = debug_macro_data.GetULEB128(offset);
      debug_line_file_idx = debug_macro_data.GetULEB128(offset);
      debug_macros_sp->AddMacroEntry(
          DebugMacroEntry::CreateStartFileEntry(line, debug_line_file_idx));
      break;
    case DW_MACRO_end_file:
      // This operation has no operands.
      debug_macros_sp->AddMacroEntry(DebugMacroEntry::CreateEndFileEntry());
      break;
    case DW_MACRO_transparent_include:
      if (offset_is_64_bit)
        new_offset = debug_macro_data.GetU64(offset);
      else
        new_offset = debug_macro_data.GetU32(offset);
      debug_macros_sp->AddMacroEntry(DebugMacroEntry::CreateIndirectEntry(
          sym_file_dwarf->ParseDebugMacros(&new_offset)));
      break;
    default:
      // TODO: Add support for other standard operations.
      // TODO: Provide mechanism to hook handling of non-standard/extension
      // operands.
      return;
    }
    type = static_cast<llvm::dwarf::MacroEntryType>(
        debug_macro_data.GetU8(offset));
  }
#endif
}

bool DWARFFormValue::ExtractValue(const DWARFDataExtractor &data,
                                  lldb::offset_t *offset_ptr) {
  bool indirect = false;
  bool is_block = false;
  m_value.data = NULL;
  uint8_t ref_addr_size;
  // Read the value for the form into value and follow and DW_FORM_indirect
  // instances we run into
  do {
    indirect = false;
    switch (m_form) {
    case DW_FORM_addr:
      assert(m_cu);
      m_value.value.uval = data.GetMaxU64(
          offset_ptr, DWARFCompileUnit::GetAddressByteSize(m_cu));
      break;
    case DW_FORM_block2:
      m_value.value.uval = data.GetU16(offset_ptr);
      is_block = true;
      break;
    case DW_FORM_block4:
      m_value.value.uval = data.GetU32(offset_ptr);
      is_block = true;
      break;
    case DW_FORM_data2:
      m_value.value.uval = data.GetU16(offset_ptr);
      break;
    case DW_FORM_data4:
      m_value.value.uval = data.GetU32(offset_ptr);
      break;
    case DW_FORM_data8:
      m_value.value.uval = data.GetU64(offset_ptr);
      break;
    case DW_FORM_string:
      m_value.value.cstr = data.GetCStr(offset_ptr);
      break;
    case DW_FORM_exprloc:
    case DW_FORM_block:
      m_value.value.uval = data.GetULEB128(offset_ptr);
      is_block = true;
      break;
    case DW_FORM_block1:
      m_value.value.uval = data.GetU8(offset_ptr);
      is_block = true;
      break;
    case DW_FORM_data1:
      m_value.value.uval = data.GetU8(offset_ptr);
      break;
    case DW_FORM_flag:
      m_value.value.uval = data.GetU8(offset_ptr);
      break;
    case DW_FORM_sdata:
      m_value.value.sval = data.GetSLEB128(offset_ptr);
      break;
    case DW_FORM_strp:
      assert(m_cu);
      m_value.value.uval =
          data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4);
      break;
    //  case DW_FORM_APPLE_db_str:
    case DW_FORM_udata:
      m_value.value.uval = data.GetULEB128(offset_ptr);
      break;
    case DW_FORM_ref_addr:
      assert(m_cu);
      ref_addr_size = 4;
      if (m_cu->GetVersion() <= 2)
        ref_addr_size = m_cu->GetAddressByteSize();
      else
        ref_addr_size = m_cu->IsDWARF64() ? 8 : 4;
      m_value.value.uval = data.GetMaxU64(offset_ptr, ref_addr_size);
      break;
    case DW_FORM_ref1:
      m_value.value.uval = data.GetU8(offset_ptr);
      break;
    case DW_FORM_ref2:
      m_value.value.uval = data.GetU16(offset_ptr);
      break;
    case DW_FORM_ref4:
      m_value.value.uval = data.GetU32(offset_ptr);
      break;
    case DW_FORM_ref8:
      m_value.value.uval = data.GetU64(offset_ptr);
      break;
    case DW_FORM_ref_udata:
      m_value.value.uval = data.GetULEB128(offset_ptr);
      break;
    case DW_FORM_indirect:
      m_form = data.GetULEB128(offset_ptr);
      indirect = true;
      break;

    case DW_FORM_sec_offset:
      assert(m_cu);
      m_value.value.uval =
          data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4);
      break;
    case DW_FORM_flag_present:
      m_value.value.uval = 1;
      break;
//.........这里部分代码省略.........