lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h

//===-- GDBRemoteCommunicationServerLLGS.h ----------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATIONSERVERLLGS_H
#define LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATIONSERVERLLGS_H

#include <mutex>
#include <unordered_map>
#include <unordered_set>

#include "lldb/Core/Communication.h"
#include "lldb/Host/MainLoop.h"
#include "lldb/Host/common/NativeProcessProtocol.h"
#include "lldb/Utility/Locked.h"
#include "lldb/Utility/RegisterValue.h"
#include "lldb/lldb-private-forward.h"

#include "GDBRemoteCommunicationServerCommon.h"
#include "LLDBServerAcceleratorPlugin.h"

class StringExtractorGDBRemote;

namespace lldb_private {

namespace process_gdb_remote {

class ProcessGDBRemote;

class GDBRemoteCommunicationServerLLGS
    : public GDBRemoteCommunicationServerCommon,
      public NativeProcessProtocol::NativeDelegate {
public:
  // Constructors and Destructors
  GDBRemoteCommunicationServerLLGS(
      MainLoop &mainloop, NativeProcessProtocol::Manager &process_manager,
      llvm::StringRef name);

  void SetLaunchInfo(const ProcessLaunchInfo &info);

  /// Launch a process with the current launch settings.
  ///
  /// This method supports running an lldb-gdbserver or similar
  /// server in a situation where the startup code has been provided
  /// with all the information for a child process to be launched.
  ///
  /// \return
  ///     An Status object indicating the success or failure of the
  ///     launch.
  Status LaunchProcess() override;

  /// Attach to a process.
  ///
  /// This method supports attaching llgs to a process accessible via the
  /// configured Platform.
  ///
  /// \return
  ///     An Status object indicating the success or failure of the
  ///     attach operation.
  Status AttachToProcess(lldb::pid_t pid);

  /// Wait to attach to a process with a given name.
  ///
  /// This method supports waiting for the next instance of a process
  /// with a given name and attaching llgs to that via the configured
  /// Platform.
  ///
  /// \return
  ///     An Status object indicating the success or failure of the
  ///     attach operation.
  Status AttachWaitProcess(llvm::StringRef process_name, bool include_existing);

  void InstallPlugin(
      std::unique_ptr<lldb_server::LLDBServerAcceleratorPlugin> plugin_up);

  /// Associate this server with the accelerator plugin for this connection.
  /// The plugin must outlive this server.
  void SetConnectionAcceleratorPlugin(
      lldb_server::LLDBServerAcceleratorPlugin &plugin) {
    m_connection_accelerator_plugin = &plugin;
  }

  // NativeProcessProtocol::NativeDelegate overrides
  void InitializeDelegate(NativeProcessProtocol *process) override;

  void ProcessStateChanged(NativeProcessProtocol *process,
                           lldb::StateType state) override;

  void DidExec(NativeProcessProtocol *process) override;

  void
  NewSubprocess(NativeProcessProtocol *parent_process,
                std::unique_ptr<NativeProcessProtocol> child_process) override;

  /// Forward a chunk of inferior stdout/stderr produced by the platform's
  /// own reader. This is used on Windows.
  void NewProcessOutput(NativeProcessProtocol *process,
                        llvm::StringRef data) override;

  /// Drain m_pending_output_buffer and emit a `$O` packet if the debuggee
  /// is currently in a running state. No-op otherwise.
  void FlushPendingProcessOutput();

  Status InitializeConnection(std::unique_ptr<Connection> connection);

  GDBRemoteCommunication::PacketResult
  SendStructuredDataPacket(const llvm::json::Value &value);

  struct DebuggedProcess {
    enum class Flag {
      vkilled = (1u << 0),

      LLVM_MARK_AS_BITMASK_ENUM(vkilled)
    };

    std::unique_ptr<NativeProcessProtocol> process_up;
    Flag flags;
  };

protected:
  MainLoop &m_mainloop;
  MainLoop::ReadHandleUP m_network_handle_up;
  NativeProcessProtocol::Manager &m_process_manager;
  std::vector<std::unique_ptr<lldb_server::LLDBServerAcceleratorPlugin>>
      m_accelerator_plugins;
  /// The plugin that owns this accelerator connection. This is null for the
  /// native connection and does not own the plugin.
  lldb_server::LLDBServerAcceleratorPlugin *m_connection_accelerator_plugin =
      nullptr;
  lldb::tid_t m_current_tid = LLDB_INVALID_THREAD_ID;
  lldb::tid_t m_continue_tid = LLDB_INVALID_THREAD_ID;
  NativeProcessProtocol *m_current_process;
  NativeProcessProtocol *m_continue_process;
  std::recursive_mutex m_debugged_process_mutex;
  std::unordered_map<lldb::pid_t, DebuggedProcess> m_debugged_processes;

  Communication m_stdio_communication;
  MainLoop::ReadHandleUP m_stdio_handle_up;

  std::string m_pending_output_buffer;
  std::mutex m_pending_output_mutex;

  llvm::StringMap<std::unique_ptr<llvm::MemoryBuffer>> m_xfer_buffer_map;

  struct SavedRegisters {
    std::unordered_map<uint32_t, lldb::DataBufferSP> map;
    uint32_t next_id = 1;
  };
  Guarded<SavedRegisters, std::mutex> m_saved_registers;

  bool m_thread_suffix_supported = false;
  bool m_address_space_suffix_supported = false;
  bool m_list_threads_in_stop_reply = false;
  bool m_non_stop = false;
  bool m_disabling_non_stop = false;
  std::deque<std::string> m_stdio_notification_queue;
  std::deque<std::string> m_stop_notification_queue;

  NativeProcessProtocol::Extension m_extensions_supported = {};

  // Typically we would use a SmallVector for this data but in this context we
  // don't know how much data we're recieving so we would have to heap allocate
  // a lot, or have a very large stack frame. So it's a member instead.
  uint8_t m_reg_bytes[RegisterValue::kMaxRegisterByteSize];

  PacketResult SendONotification(const char *buffer, uint32_t len);

  PacketResult SendWResponse(NativeProcessProtocol *process);

  StreamString PrepareStopReplyPacketForThread(NativeThreadProtocol &thread);

  PacketResult SendStopReplyPacketForThread(NativeProcessProtocol &process,
                                            lldb::tid_t tid,
                                            bool force_synchronous);

  PacketResult SendStopReasonForState(NativeProcessProtocol &process,
                                      lldb::StateType process_state,
                                      bool force_synchronous);

  void EnqueueStopReplyPackets(lldb::tid_t thread_to_skip);

  PacketResult Handle_k(StringExtractorGDBRemote &packet);

  PacketResult Handle_vKill(StringExtractorGDBRemote &packet);

  PacketResult Handle_qProcessInfo(StringExtractorGDBRemote &packet);

  PacketResult Handle_qC(StringExtractorGDBRemote &packet);

  PacketResult Handle_QSetDisableASLR(StringExtractorGDBRemote &packet);

  PacketResult Handle_QSetWorkingDir(StringExtractorGDBRemote &packet);

  PacketResult Handle_qGetWorkingDir(StringExtractorGDBRemote &packet);

  PacketResult Handle_QThreadSuffixSupported(StringExtractorGDBRemote &packet);

  PacketResult Handle_QListThreadsInStopReply(StringExtractorGDBRemote &packet);

  PacketResult ResumeProcess(NativeProcessProtocol &process,
                             const ResumeActionList &actions);

  PacketResult Handle_C(StringExtractorGDBRemote &packet);

  PacketResult Handle_c(StringExtractorGDBRemote &packet);

  PacketResult Handle_vCont(StringExtractorGDBRemote &packet);

  PacketResult Handle_vCont_actions(StringExtractorGDBRemote &packet);

  PacketResult Handle_stop_reason(StringExtractorGDBRemote &packet);

  PacketResult Handle_qRegisterInfo(StringExtractorGDBRemote &packet);

  void AddProcessThreads(StreamGDBRemote &response,
                         NativeProcessProtocol &process, bool &had_any);

  PacketResult Handle_qfThreadInfo(StringExtractorGDBRemote &packet);

  PacketResult Handle_qsThreadInfo(StringExtractorGDBRemote &packet);

  PacketResult Handle_qStructuredDataPlugins(StringExtractorGDBRemote &packet);

  PacketResult Handle_p(StringExtractorGDBRemote &packet);

  PacketResult Handle_P(StringExtractorGDBRemote &packet);

  PacketResult Handle_H(StringExtractorGDBRemote &packet);

  PacketResult Handle_I(StringExtractorGDBRemote &packet);

  PacketResult Handle_interrupt(StringExtractorGDBRemote &packet);

  // Handles $m and $x packets.
  PacketResult Handle_memory_read(StringExtractorGDBRemote &packet);

  PacketResult Handle_M(StringExtractorGDBRemote &packet);
  PacketResult Handle__M(StringExtractorGDBRemote &packet);
  PacketResult Handle__m(StringExtractorGDBRemote &packet);

  PacketResult
  Handle_qMemoryRegionInfoSupported(StringExtractorGDBRemote &packet);

  PacketResult Handle_qMemoryRegionInfo(StringExtractorGDBRemote &packet);

  PacketResult Handle_Z(StringExtractorGDBRemote &packet);

  PacketResult Handle_z(StringExtractorGDBRemote &packet);

  PacketResult Handle_s(StringExtractorGDBRemote &packet);

  PacketResult Handle_qXfer(StringExtractorGDBRemote &packet);

  PacketResult Handle_QSaveRegisterState(StringExtractorGDBRemote &packet);

  PacketResult Handle_jLLDBTraceSupported(StringExtractorGDBRemote &packet);

  PacketResult Handle_jLLDBTraceStart(StringExtractorGDBRemote &packet);

  PacketResult Handle_jLLDBTraceStop(StringExtractorGDBRemote &packet);

  PacketResult Handle_jLLDBTraceGetState(StringExtractorGDBRemote &packet);

  PacketResult Handle_jLLDBTraceGetBinaryData(StringExtractorGDBRemote &packet);

  PacketResult Handle_QRestoreRegisterState(StringExtractorGDBRemote &packet);

  PacketResult Handle_vAttach(StringExtractorGDBRemote &packet);

  PacketResult Handle_vAttachWait(StringExtractorGDBRemote &packet);

  PacketResult Handle_qVAttachOrWaitSupported(StringExtractorGDBRemote &packet);

  PacketResult Handle_vAttachOrWait(StringExtractorGDBRemote &packet);

  PacketResult Handle_vRun(StringExtractorGDBRemote &packet);

  PacketResult Handle_D(StringExtractorGDBRemote &packet);

  PacketResult Handle_qThreadStopInfo(StringExtractorGDBRemote &packet);

  PacketResult Handle_jThreadsInfo(StringExtractorGDBRemote &packet);

  PacketResult Handle_jAddressSpacesInfo(StringExtractorGDBRemote &packet);

  PacketResult Handle_qWatchpointSupportInfo(StringExtractorGDBRemote &packet);

  PacketResult Handle_qFileLoadAddress(StringExtractorGDBRemote &packet);

  PacketResult Handle_QPassSignals(StringExtractorGDBRemote &packet);

  PacketResult Handle_qSaveCore(StringExtractorGDBRemote &packet);

  PacketResult Handle_QNonStop(StringExtractorGDBRemote &packet);

  PacketResult HandleNotificationAck(std::deque<std::string> &queue);

  PacketResult Handle_vStdio(StringExtractorGDBRemote &packet);

  PacketResult Handle_vStopped(StringExtractorGDBRemote &packet);

  PacketResult Handle_vCtrlC(StringExtractorGDBRemote &packet);

  PacketResult Handle_g(StringExtractorGDBRemote &packet);

  PacketResult Handle_qMemTags(StringExtractorGDBRemote &packet);

  PacketResult Handle_QMemTags(StringExtractorGDBRemote &packet);

  PacketResult Handle_T(StringExtractorGDBRemote &packet);

  PacketResult Handle_jMultiBreakpoint(StringExtractorGDBRemote &packet);

  PacketResult Handle_jLLDBSettings(StringExtractorGDBRemote &packet);

  PacketResult
  Handle_jAcceleratorPluginInitialize(StringExtractorGDBRemote &packet);

  PacketResult
  Handle_jAcceleratorPluginBreakpointHit(StringExtractorGDBRemote &packet);

  PacketResult Handle_jAcceleratorPluginGetDynamicLoaderLibraryInfo(
      StringExtractorGDBRemote &packet);

  PacketResult Handle_jThreadExtendedInfo(StringExtractorGDBRemote &packet);

  void SetCurrentThreadID(lldb::tid_t tid);

  lldb::tid_t GetCurrentThreadID() const;

  void SetContinueThreadID(lldb::tid_t tid);

  lldb::tid_t GetContinueThreadID() const { return m_continue_tid; }

  Status SetSTDIOFileDescriptor(int fd);

  FileSpec FindModuleFile(const std::string &module_path,
                          const ArchSpec &arch) override;

  llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
  ReadXferObject(llvm::StringRef object, llvm::StringRef annex);

  static std::string XMLEncodeAttributeValue(llvm::StringRef value);

  std::vector<std::string> HandleFeatures(
      const llvm::ArrayRef<llvm::StringRef> client_features) override;

  // Provide a response for successful continue action, i.e. send "OK"
  // in non-stop mode, no response otherwise.
  PacketResult SendContinueSuccessResponse();

  void AppendThreadIDToResponse(Stream &response, lldb::pid_t pid,
                                lldb::tid_t tid);

private:
  llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>> BuildTargetXml();

  struct BreakpointOK {};
  struct BreakpointIllFormed {
    std::string message;
  };
  struct BreakpointError {
    uint8_t error_code;
  };

  using BreakpointResult =
      std::variant<BreakpointOK, BreakpointIllFormed, BreakpointError>;

  /// Core logic for a Z (set breakpoint/watchpoint) request.
  BreakpointResult ExecuteSetBreakpoint(llvm::StringRef packet_str);

  /// Core logic for a z (remove breakpoint/watchpoint) request.
  BreakpointResult ExecuteRemoveBreakpoint(llvm::StringRef packet_str);

  /// Convert a BreakpointResult into a PacketResult, sending the appropriate
  /// response.
  PacketResult SendBreakpointResponse(StringExtractorGDBRemote &packet,
                                      const BreakpointResult &result);

  void HandleInferiorState_Exited(NativeProcessProtocol *process);

  void HandleInferiorState_Stopped(NativeProcessProtocol *process);

  NativeThreadProtocol *GetThreadFromSuffix(StringExtractorGDBRemote &packet);

  uint32_t GetNextSavedRegistersID();

  void MaybeCloseInferiorTerminalConnection();

  void ClearProcessSpecificData();

  void RegisterPacketHandlers();

  void DataAvailableCallback();

  void SendProcessOutput();

  void StartSTDIOForwarding();

  void StopSTDIOForwarding();

  // Call SetEnabledExtensions() with appropriate flags on the process.
  void SetEnabledExtensions(NativeProcessProtocol &process);

  // For GDBRemoteCommunicationServerLLGS only
  GDBRemoteCommunicationServerLLGS(const GDBRemoteCommunicationServerLLGS &) =
      delete;
  const GDBRemoteCommunicationServerLLGS &
  operator=(const GDBRemoteCommunicationServerLLGS &) = delete;
};

std::string LLGSArgToURL(llvm::StringRef url_arg, bool reverse_connect);

} // namespace process_gdb_remote
} // namespace lldb_private

#endif // LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATIONSERVERLLGS_H