C++ DataExtractor::Clear方法代码示例

uint32_t Opcode::GetData(DataExtractor &data) const {
  uint32_t byte_size = GetByteSize();
  uint8_t swap_buf[8];
  const void *buf = nullptr;

  if (byte_size > 0) {
    if (!GetEndianSwap()) {
      if (m_type == Opcode::eType16_2) {
        // 32 bit thumb instruction, we need to sizzle this a bit
        swap_buf[0] = m_data.inst.bytes[2];
        swap_buf[1] = m_data.inst.bytes[3];
        swap_buf[2] = m_data.inst.bytes[0];
        swap_buf[3] = m_data.inst.bytes[1];
        buf = swap_buf;
      } else {
        buf = GetOpcodeDataBytes();
      }
    } else {
      switch (m_type) {
      case Opcode::eTypeInvalid:
        break;
      case Opcode::eType8:
        buf = GetOpcodeDataBytes();
        break;
      case Opcode::eType16:
        *(uint16_t *)swap_buf = llvm::ByteSwap_16(m_data.inst16);
        buf = swap_buf;
        break;
      case Opcode::eType16_2:
        swap_buf[0] = m_data.inst.bytes[1];
        swap_buf[1] = m_data.inst.bytes[0];
        swap_buf[2] = m_data.inst.bytes[3];
        swap_buf[3] = m_data.inst.bytes[2];
        buf = swap_buf;
        break;
      case Opcode::eType32:
        *(uint32_t *)swap_buf = llvm::ByteSwap_32(m_data.inst32);
        buf = swap_buf;
        break;
      case Opcode::eType64:
        *(uint32_t *)swap_buf = llvm::ByteSwap_64(m_data.inst64);
        buf = swap_buf;
        break;
      case Opcode::eTypeBytes:
        buf = GetOpcodeDataBytes();
        break;
      }
    }
  }
  if (buf != nullptr) {
    DataBufferSP buffer_sp;

    buffer_sp.reset(new DataBufferHeap(buf, byte_size));
    data.SetByteOrder(GetDataByteOrder());
    data.SetData(buffer_sp);
    return byte_size;
  }
  data.Clear();
  return 0;
}

size_t CommunicationKDP::WaitForPacketWithTimeoutMicroSecondsNoLock(
    DataExtractor &packet, uint32_t timeout_usec) {
  uint8_t buffer[8192];
  Status error;

  Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PACKETS));

  // Check for a packet from our cache first without trying any reading...
  if (CheckForPacket(NULL, 0, packet))
    return packet.GetByteSize();

  bool timed_out = false;
  while (IsConnected() && !timed_out) {
    lldb::ConnectionStatus status = eConnectionStatusNoConnection;
    size_t bytes_read = Read(buffer, sizeof(buffer),
                             timeout_usec == UINT32_MAX
                                 ? Timeout<std::micro>(llvm::None)
                                 : std::chrono::microseconds(timeout_usec),
                             status, &error);

    LLDB_LOGV(log, 
      "Read (buffer, sizeof(buffer), timeout_usec = 0x{0:x}, "
                  "status = {1}, error = {2}) => bytes_read = {4}",
                  timeout_usec,
                  Communication::ConnectionStatusAsCString(status),
                  error, bytes_read);

    if (bytes_read > 0) {
      if (CheckForPacket(buffer, bytes_read, packet))
        return packet.GetByteSize();
    } else {
      switch (status) {
      case eConnectionStatusInterrupted:
      case eConnectionStatusTimedOut:
        timed_out = true;
        break;
      case eConnectionStatusSuccess:
        // printf ("status = success but error = %s\n",
        // error.AsCString("<invalid>"));
        break;

      case eConnectionStatusEndOfFile:
      case eConnectionStatusNoConnection:
      case eConnectionStatusLostConnection:
      case eConnectionStatusError:
        Disconnect();
        break;
      }
    }
  }
  packet.Clear();
  return 0;
}

uint32_t
Opcode::GetData (DataExtractor &data, lldb::AddressClass address_class) const
{
    uint32_t byte_size = GetByteSize ();
    
    DataBufferSP buffer_sp;
    if (byte_size > 0)
    {
        switch (m_type)
        {
            case Opcode::eTypeInvalid:
                break;
                
            case Opcode::eType8:    buffer_sp.reset (new DataBufferHeap (&m_data.inst8,  byte_size)); break;
            case Opcode::eType16:   buffer_sp.reset (new DataBufferHeap (&m_data.inst16, byte_size)); break;
            case Opcode::eType32:
                {
                    // The only thing that uses eAddressClassCodeAlternateISA currently
                    // is Thumb. If this ever changes, we will need to pass in more
                    // information like an additional "const ArchSpec &arch". For now
                    // this will do
                    if (address_class == eAddressClassCodeAlternateISA)
                    {
                        // 32 bit thumb instruction, we need to sizzle this a bit
                        uint8_t buf[4];
                        buf[0] = m_data.inst.bytes[2];
                        buf[1] = m_data.inst.bytes[3];
                        buf[2] = m_data.inst.bytes[0];
                        buf[3] = m_data.inst.bytes[1];
                        buffer_sp.reset (new DataBufferHeap (buf, byte_size));
                        break;
                    }
                    buffer_sp.reset (new DataBufferHeap (&m_data.inst32, byte_size));
                }
                break;

            case Opcode::eType64:   buffer_sp.reset (new DataBufferHeap (&m_data.inst64, byte_size)); break;
            case Opcode::eTypeBytes:buffer_sp.reset (new DataBufferHeap (GetOpcodeBytes(), byte_size)); break;
                break;
        }
    }
    
    if (buffer_sp)
    {
        data.SetByteOrder(GetDataByteOrder());
        data.SetData (buffer_sp);
        return byte_size;
    }
    data.Clear();
    return 0;
}

Error
Value::GetValueAsData (ExecutionContext *exe_ctx,
                       DataExtractor &data,
                       uint32_t data_offset,
                       Module *module)
{
    data.Clear();

    Error error;
    lldb::addr_t address = LLDB_INVALID_ADDRESS;
    AddressType address_type = eAddressTypeFile;
    Address file_so_addr;
    const CompilerType &ast_type = GetCompilerType();
    switch (m_value_type)
    {
    case eValueTypeVector:
        if (ast_type.IsValid())
            data.SetAddressByteSize (ast_type.GetPointerByteSize());
        else
            data.SetAddressByteSize(sizeof(void *));
        data.SetData(m_vector.bytes, m_vector.length, m_vector.byte_order);
        break;

    case eValueTypeScalar:
        {
            data.SetByteOrder (endian::InlHostByteOrder());
            if (ast_type.IsValid())
                data.SetAddressByteSize (ast_type.GetPointerByteSize());
            else
                data.SetAddressByteSize(sizeof(void *));

            uint32_t limit_byte_size = UINT32_MAX;
            
            if (ast_type.IsValid() && ast_type.IsScalarType())
            {
                uint64_t type_encoding_count = 0;
                lldb::Encoding type_encoding = ast_type.GetEncoding(type_encoding_count);
                
                if (type_encoding == eEncodingUint || type_encoding == eEncodingSint)
                    limit_byte_size = ast_type.GetByteSize(exe_ctx ? exe_ctx->GetBestExecutionContextScope() : nullptr);
            }
            
            if (m_value.GetData (data, limit_byte_size))
                return error;   // Success;
            
            error.SetErrorStringWithFormat("extracting data from value failed");
            break;
        }
    case eValueTypeLoadAddress:
        if (exe_ctx == NULL)
        {
            error.SetErrorString ("can't read load address (no execution context)");
        }
        else 
        {
            Process *process = exe_ctx->GetProcessPtr();
            if (process == NULL || !process->IsAlive())
            {
                Target *target = exe_ctx->GetTargetPtr();
                if (target)
                {
                    // Allow expressions to run and evaluate things when the target
                    // has memory sections loaded. This allows you to use "target modules load"
                    // to load your executable and any shared libraries, then execute
                    // commands where you can look at types in data sections.
                    const SectionLoadList &target_sections = target->GetSectionLoadList();
                    if (!target_sections.IsEmpty())
                    {
                        address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
                        if (target_sections.ResolveLoadAddress(address, file_so_addr))
                        {
                            address_type = eAddressTypeLoad;
                            data.SetByteOrder(target->GetArchitecture().GetByteOrder());
                            data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
                        }
                        else
                            address = LLDB_INVALID_ADDRESS;
                    }
//                    else
//                    {
//                        ModuleSP exe_module_sp (target->GetExecutableModule());
//                        if (exe_module_sp)
//                        {
//                            address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
//                            if (address != LLDB_INVALID_ADDRESS)
//                            {
//                                if (exe_module_sp->ResolveFileAddress(address, file_so_addr))
//                                {
//                                    data.SetByteOrder(target->GetArchitecture().GetByteOrder());
//                                    data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
//                                    address_type = eAddressTypeFile;
//                                }
//                                else
//                                {
//                                    address = LLDB_INVALID_ADDRESS;
//                                }
//                            }
//                        }
//                    }
                }
//.........这里部分代码省略.........

bool CommunicationKDP::SendRequestAndGetReply(
    const CommandType command, const PacketStreamType &request_packet,
    DataExtractor &reply_packet) {
  if (IsRunning()) {
    Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PACKETS));
    if (log) {
      PacketStreamType log_strm;
      DumpPacket(log_strm, request_packet.GetData(), request_packet.GetSize());
      log->Printf("error: kdp running, not sending packet: %.*s",
                  (uint32_t)log_strm.GetSize(), log_strm.GetData());
    }
    return false;
  }

  std::lock_guard<std::recursive_mutex> guard(m_sequence_mutex);
#ifdef LLDB_CONFIGURATION_DEBUG
  // NOTE: this only works for packets that are in native endian byte order
  assert(request_packet.GetSize() ==
         *((const uint16_t *)(request_packet.GetData() + 2)));
#endif
  lldb::offset_t offset = 1;
  const uint32_t num_retries = 3;
  for (uint32_t i = 0; i < num_retries; ++i) {
    if (SendRequestPacketNoLock(request_packet)) {
      const uint8_t request_sequence_id = (uint8_t)request_packet.GetData()[1];
      while (1) {
        if (WaitForPacketWithTimeoutMicroSecondsNoLock(
                reply_packet,
                std::chrono::microseconds(GetPacketTimeout()).count())) {
          offset = 0;
          const uint8_t reply_command = reply_packet.GetU8(&offset);
          const uint8_t reply_sequence_id = reply_packet.GetU8(&offset);
          if (request_sequence_id == reply_sequence_id) {
            // The sequent ID was correct, now verify we got the response we
            // were looking for
            if ((reply_command & eCommandTypeMask) == command) {
              // Success
              if (command == KDP_RESUMECPUS)
                m_is_running.SetValue(true, eBroadcastAlways);
              return true;
            } else {
              // Failed to get the correct response, bail
              reply_packet.Clear();
              return false;
            }
          } else if (reply_sequence_id > request_sequence_id) {
            // Sequence ID was greater than the sequence ID of the packet we
            // sent, something is really wrong...
            reply_packet.Clear();
            return false;
          } else {
            // The reply sequence ID was less than our current packet's
            // sequence ID so we should keep trying to get a response because
            // this was a response for a previous packet that we must have
            // retried.
          }
        } else {
          // Break and retry sending the packet as we didn't get a response due
          // to timeout
          break;
        }
      }
    }
  }
  reply_packet.Clear();
  return false;
}

//.........这里部分代码省略.........
  std::lock_guard<std::recursive_mutex> guard(m_bytes_mutex);

  Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PACKETS));

  if (src && src_len > 0) {
    if (log && log->GetVerbose()) {
      PacketStreamType log_strm;
      DumpHexBytes(&log_strm, src, src_len, UINT32_MAX, LLDB_INVALID_ADDRESS);
      log->Printf("CommunicationKDP::%s adding %u bytes: %s", __FUNCTION__,
                  (uint32_t)src_len, log_strm.GetData());
    }
    m_bytes.append((const char *)src, src_len);
  }

  // Make sure we at least have enough bytes for a packet header
  const size_t bytes_available = m_bytes.size();
  if (bytes_available >= 8) {
    packet.SetData(&m_bytes[0], bytes_available, m_byte_order);
    lldb::offset_t offset = 0;
    uint8_t reply_command = packet.GetU8(&offset);
    switch (reply_command) {
    case ePacketTypeRequest | KDP_EXCEPTION:
    case ePacketTypeRequest | KDP_TERMINATION:
      // We got an exception request, so be sure to send an ACK
      {
        PacketStreamType request_ack_packet(Stream::eBinary, m_addr_byte_size,
                                            m_byte_order);
        // Set the reply but and make the ACK packet
        request_ack_packet.PutHex8(reply_command | ePacketTypeReply);
        request_ack_packet.PutHex8(packet.GetU8(&offset));
        request_ack_packet.PutHex16(packet.GetU16(&offset));
        request_ack_packet.PutHex32(packet.GetU32(&offset));
        m_is_running.SetValue(false, eBroadcastAlways);
        // Ack to the exception or termination
        SendRequestPacketNoLock(request_ack_packet);
      }
      // Fall through to case below to get packet contents
      LLVM_FALLTHROUGH;
    case ePacketTypeReply | KDP_CONNECT:
    case ePacketTypeReply | KDP_DISCONNECT:
    case ePacketTypeReply | KDP_HOSTINFO:
    case ePacketTypeReply | KDP_VERSION:
    case ePacketTypeReply | KDP_MAXBYTES:
    case ePacketTypeReply | KDP_READMEM:
    case ePacketTypeReply | KDP_WRITEMEM:
    case ePacketTypeReply | KDP_READREGS:
    case ePacketTypeReply | KDP_WRITEREGS:
    case ePacketTypeReply | KDP_LOAD:
    case ePacketTypeReply | KDP_IMAGEPATH:
    case ePacketTypeReply | KDP_SUSPEND:
    case ePacketTypeReply | KDP_RESUMECPUS:
    case ePacketTypeReply | KDP_BREAKPOINT_SET:
    case ePacketTypeReply | KDP_BREAKPOINT_REMOVE:
    case ePacketTypeReply | KDP_REGIONS:
    case ePacketTypeReply | KDP_REATTACH:
    case ePacketTypeReply | KDP_HOSTREBOOT:
    case ePacketTypeReply | KDP_READMEM64:
    case ePacketTypeReply | KDP_WRITEMEM64:
    case ePacketTypeReply | KDP_BREAKPOINT_SET64:
    case ePacketTypeReply | KDP_BREAKPOINT_REMOVE64:
    case ePacketTypeReply | KDP_KERNELVERSION:
    case ePacketTypeReply | KDP_READPHYSMEM64:
    case ePacketTypeReply | KDP_WRITEPHYSMEM64:
    case ePacketTypeReply | KDP_READIOPORT:
    case ePacketTypeReply | KDP_WRITEIOPORT:
    case ePacketTypeReply | KDP_READMSR64:
    case ePacketTypeReply | KDP_WRITEMSR64:
    case ePacketTypeReply | KDP_DUMPINFO: {
      offset = 2;
      const uint16_t length = packet.GetU16(&offset);
      if (length <= bytes_available) {
        // We have an entire packet ready, we need to copy the data bytes into
        // a buffer that will be owned by the packet and erase the bytes from
        // our communcation buffer "m_bytes"
        packet.SetData(DataBufferSP(new DataBufferHeap(&m_bytes[0], length)));
        m_bytes.erase(0, length);

        if (log) {
          PacketStreamType log_strm;
          DumpPacket(log_strm, packet);

          log->Printf("%.*s", (uint32_t)log_strm.GetSize(), log_strm.GetData());
        }
        return true;
      }
    } break;

    default:
      // Unrecognized reply command byte, erase this byte and try to get back
      // on track
      if (log)
        log->Printf("CommunicationKDP::%s: tossing junk byte: 0x%2.2x",
                    __FUNCTION__, (uint8_t)m_bytes[0]);
      m_bytes.erase(0, 1);
      break;
    }
  }
  packet.Clear();
  return false;
}

Error
Value::GetValueAsData (ExecutionContext *exe_ctx, 
                       clang::ASTContext *ast_context, 
                       DataExtractor &data, 
                       uint32_t data_offset,
                       Module *module)
{
    data.Clear();

    Error error;
    lldb::addr_t address = LLDB_INVALID_ADDRESS;
    AddressType address_type = eAddressTypeFile;
    Address file_so_addr;
    switch (m_value_type)
    {
    default:
        error.SetErrorStringWithFormat("invalid value type %i", m_value_type);
        break;

    case eValueTypeScalar:
        data.SetByteOrder (lldb::endian::InlHostByteOrder());
        if (m_context_type == eContextTypeClangType && ast_context)
        {
            uint32_t ptr_bit_width = ClangASTType::GetClangTypeBitWidth (ast_context, 
                                                                     ClangASTContext::GetVoidPtrType(ast_context, false));
            uint32_t ptr_byte_size = (ptr_bit_width + 7) / 8;
            data.SetAddressByteSize (ptr_byte_size);
        }
        else
            data.SetAddressByteSize(sizeof(void *));
        if (m_value.GetData (data))
            return error;   // Success;
        error.SetErrorStringWithFormat("extracting data from value failed");
        break;

    case eValueTypeLoadAddress:
        if (exe_ctx == NULL)
        {
            error.SetErrorString ("can't read load address (no execution context)");
        }
        else 
        {
            Process *process = exe_ctx->GetProcessPtr();
            if (process == NULL)
            {
                error.SetErrorString ("can't read load address (invalid process)");
            }
            else
            {
                address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
                address_type = eAddressTypeLoad;
                data.SetByteOrder(process->GetTarget().GetArchitecture().GetByteOrder());
                data.SetAddressByteSize(process->GetTarget().GetArchitecture().GetAddressByteSize());
            }
        }
        break;

    case eValueTypeFileAddress:
        if (exe_ctx == NULL)
        {
            error.SetErrorString ("can't read file address (no execution context)");
        }
        else if (exe_ctx->GetTargetPtr() == NULL)
        {
            error.SetErrorString ("can't read file address (invalid target)");
        }
        else
        {
            address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
            if (address == LLDB_INVALID_ADDRESS)
            {
                error.SetErrorString ("invalid file address");
            }
            else
            {
                if (module == NULL)
                {
                    // The only thing we can currently lock down to a module so that
                    // we can resolve a file address, is a variable.
                    Variable *variable = GetVariable();
                    if (variable)
                    {
                        SymbolContext var_sc;
                        variable->CalculateSymbolContext(&var_sc);
                        module = var_sc.module_sp.get();
                    }
                }
                
                if (module)
                {
                    bool resolved = false;
                    ObjectFile *objfile = module->GetObjectFile();
                    if (objfile)
                    {
                        Address so_addr(address, objfile->GetSectionList());
                        addr_t load_address = so_addr.GetLoadAddress (exe_ctx->GetTargetPtr());
                        bool process_launched_and_stopped = exe_ctx->GetProcessPtr()
                            ? StateIsStoppedState(exe_ctx->GetProcessPtr()->GetState(), true /* must_exist */)
                            : false;
                        // Don't use the load address if the process has exited.
//.........这里部分代码省略.........