C++ DataExtractor::CopyByteOrderedData方法代码示例

Error
RegisterValue::SetValueFromData (const RegisterInfo *reg_info, DataExtractor &src, lldb::offset_t src_offset, bool partial_data_ok)
{
    Error error;
    
    if (src.GetByteSize() == 0)
    {
        error.SetErrorString ("empty data.");
        return error;
    }

    if (reg_info->byte_size == 0)
    {
        error.SetErrorString ("invalid register info.");
        return error;
    }

    uint32_t src_len = src.GetByteSize() - src_offset;
    
    if (!partial_data_ok && (src_len < reg_info->byte_size))
    {
        error.SetErrorString ("not enough data.");
        return error;
    }
        
    // Cap the data length if there is more than enough bytes for this register
    // value
    if (src_len > reg_info->byte_size)
        src_len = reg_info->byte_size;

    // Zero out the value in case we get partial data...
    memset (m_data.buffer.bytes, 0, sizeof (m_data.buffer.bytes));
    
    switch (SetType (reg_info))
    {
        case eTypeInvalid:
            error.SetErrorString("");
            break;
        case eTypeUInt8:    SetUInt8  (src.GetMaxU32 (&src_offset, src_len)); break;
        case eTypeUInt16:   SetUInt16 (src.GetMaxU32 (&src_offset, src_len)); break;
        case eTypeUInt32:   SetUInt32 (src.GetMaxU32 (&src_offset, src_len)); break;
        case eTypeUInt64:   SetUInt64 (src.GetMaxU64 (&src_offset, src_len)); break;
#if defined (ENABLE_128_BIT_SUPPORT)
        case eTypeUInt128:
            {
                __uint128_t data1 = src.GetU64 (&src_offset);
                __uint128_t data2 = src.GetU64 (&src_offset);
                if (src.GetByteSize() == eByteOrderBig)
                    SetUInt128 (data1 << 64 + data2);
                else
                    SetUInt128 (data2 << 64 + data1);
            }
            break;
#endif
        case eTypeFloat:        SetFloat (src.GetFloat (&src_offset));      break;
        case eTypeDouble:       SetDouble(src.GetDouble (&src_offset));     break;
        case eTypeLongDouble:   SetFloat (src.GetLongDouble (&src_offset)); break;
        case eTypeBytes:
        {
            m_data.buffer.length = reg_info->byte_size;
            m_data.buffer.byte_order = src.GetByteOrder();
            assert (m_data.buffer.length <= kMaxRegisterByteSize);
            if (m_data.buffer.length > kMaxRegisterByteSize)
                m_data.buffer.length = kMaxRegisterByteSize;
            if (src.CopyByteOrderedData (src_offset,                    // offset within "src" to start extracting data
                                         src_len,                       // src length
                                         m_data.buffer.bytes,           // dst buffer
                                         m_data.buffer.length,          // dst length
                                         m_data.buffer.byte_order) == 0)// dst byte order
            {
                error.SetErrorString ("data copy failed data.");
                return error;
            }
        }
    }
    
    return error;
}

Status ABISysV_ppc64::SetReturnValueObject(lldb::StackFrameSP &frame_sp,
                                           lldb::ValueObjectSP &new_value_sp) {
  Status error;
  if (!new_value_sp) {
    error.SetErrorString("Empty value object for return value.");
    return error;
  }

  CompilerType compiler_type = new_value_sp->GetCompilerType();
  if (!compiler_type) {
    error.SetErrorString("Null clang type for return value.");
    return error;
  }

  Thread *thread = frame_sp->GetThread().get();

  bool is_signed;
  uint32_t count;
  bool is_complex;

  RegisterContext *reg_ctx = thread->GetRegisterContext().get();

  bool set_it_simple = false;
  if (compiler_type.IsIntegerOrEnumerationType(is_signed) ||
      compiler_type.IsPointerType()) {
    const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName("r3", 0);

    DataExtractor data;
    Status data_error;
    size_t num_bytes = new_value_sp->GetData(data, data_error);
    if (data_error.Fail()) {
      error.SetErrorStringWithFormat(
          "Couldn't convert return value to raw data: %s",
          data_error.AsCString());
      return error;
    }
    lldb::offset_t offset = 0;
    if (num_bytes <= 8) {
      uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);

      if (reg_ctx->WriteRegisterFromUnsigned(reg_info, raw_value))
        set_it_simple = true;
    } else {
      error.SetErrorString("We don't support returning longer than 64 bit "
                           "integer values at present.");
    }
  } else if (compiler_type.IsFloatingPointType(count, is_complex)) {
    if (is_complex)
      error.SetErrorString(
          "We don't support returning complex values at present");
    else {
      size_t bit_width = compiler_type.GetBitSize(frame_sp.get());
      if (bit_width <= 64) {
        DataExtractor data;
        Status data_error;
        size_t num_bytes = new_value_sp->GetData(data, data_error);
        if (data_error.Fail()) {
          error.SetErrorStringWithFormat(
              "Couldn't convert return value to raw data: %s",
              data_error.AsCString());
          return error;
        }

        unsigned char buffer[16];
        ByteOrder byte_order = data.GetByteOrder();

        data.CopyByteOrderedData(0, num_bytes, buffer, 16, byte_order);
        set_it_simple = true;
      } else {
        // FIXME - don't know how to do 80 bit long doubles yet.
        error.SetErrorString(
            "We don't support returning float values > 64 bits at present");
      }
    }
  }

  if (!set_it_simple) {
    // Okay we've got a structure or something that doesn't fit in a simple
    // register.
    // We should figure out where it really goes, but we don't support this yet.
    error.SetErrorString("We only support setting simple integer and float "
                         "return types at present.");
  }

  return error;
}

Error RegisterValue::SetValueFromData(const RegisterInfo *reg_info,
                                      DataExtractor &src,
                                      lldb::offset_t src_offset,
                                      bool partial_data_ok) {
  Error error;

  if (src.GetByteSize() == 0) {
    error.SetErrorString("empty data.");
    return error;
  }

  if (reg_info->byte_size == 0) {
    error.SetErrorString("invalid register info.");
    return error;
  }

  uint32_t src_len = src.GetByteSize() - src_offset;

  if (!partial_data_ok && (src_len < reg_info->byte_size)) {
    error.SetErrorString("not enough data.");
    return error;
  }

  // Cap the data length if there is more than enough bytes for this register
  // value
  if (src_len > reg_info->byte_size)
    src_len = reg_info->byte_size;

  // Zero out the value in case we get partial data...
  memset(buffer.bytes, 0, sizeof(buffer.bytes));

  type128 int128;

  m_type = eTypeInvalid;
  switch (reg_info->encoding) {
  case eEncodingInvalid:
    break;
  case eEncodingUint:
  case eEncodingSint:
    if (reg_info->byte_size == 1)
      SetUInt8(src.GetMaxU32(&src_offset, src_len));
    else if (reg_info->byte_size <= 2)
      SetUInt16(src.GetMaxU32(&src_offset, src_len));
    else if (reg_info->byte_size <= 4)
      SetUInt32(src.GetMaxU32(&src_offset, src_len));
    else if (reg_info->byte_size <= 8)
      SetUInt64(src.GetMaxU64(&src_offset, src_len));
    else if (reg_info->byte_size <= 16) {
      uint64_t data1 = src.GetU64(&src_offset);
      uint64_t data2 = src.GetU64(&src_offset);
      if (src.GetByteSize() == eByteOrderBig) {
        int128.x[0] = data1;
        int128.x[1] = data2;
      } else {
        int128.x[0] = data2;
        int128.x[1] = data1;
      }
      SetUInt128(llvm::APInt(128, 2, int128.x));
    }
    break;
  case eEncodingIEEE754:
    if (reg_info->byte_size == sizeof(float))
      SetFloat(src.GetFloat(&src_offset));
    else if (reg_info->byte_size == sizeof(double))
      SetDouble(src.GetDouble(&src_offset));
    else if (reg_info->byte_size == sizeof(long double))
      SetLongDouble(src.GetLongDouble(&src_offset));
    break;
  case eEncodingVector: {
    m_type = eTypeBytes;
    buffer.length = reg_info->byte_size;
    buffer.byte_order = src.GetByteOrder();
    assert(buffer.length <= kMaxRegisterByteSize);
    if (buffer.length > kMaxRegisterByteSize)
      buffer.length = kMaxRegisterByteSize;
    if (src.CopyByteOrderedData(
            src_offset,    // offset within "src" to start extracting data
            src_len,       // src length
            buffer.bytes,  // dst buffer
            buffer.length, // dst length
            buffer.byte_order) == 0) // dst byte order
    {
      error.SetErrorStringWithFormat(
          "failed to copy data for register write of %s", reg_info->name);
      return error;
    }
  }
  }

  if (m_type == eTypeInvalid)
    error.SetErrorStringWithFormat(
        "invalid register value type for register %s", reg_info->name);
  return error;
}