//===-- NativeProcessProtocol.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_HOST_COMMON_NATIVEPROCESSPROTOCOL_H

#define LLDB_HOST_COMMON_NATIVEPROCESSPROTOCOL_H

#include "NativeBreakpointList.h"

#include "NativeThreadProtocol.h"

#include "NativeWatchpointList.h"

#include "lldb/Host/Host.h"

#include "lldb/Host/MainLoop.h"

#include "lldb/Utility/ArchSpec.h"

#include "lldb/Utility/Iterable.h"

#include "lldb/Utility/Status.h"

#include "lldb/Utility/TraceGDBRemotePackets.h"

#include "lldb/Utility/UnimplementedError.h"

#include "lldb/lldb-private-forward.h"

#include "lldb/lldb-types.h"

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/DenseSet.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/Error.h"

#include "llvm/Support/MemoryBuffer.h"

#include <mutex>

#include <unordered_map>

#include <vector>

namespace lldb_private {

LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();

class MemoryRegionInfo;

class ResumeActionList;

struct SVR4LibraryInfo {

  std::string name;

  lldb::addr_t link_map;

  lldb::addr_t base_addr;

  lldb::addr_t ld_addr;

  lldb::addr_t next;

};

// NativeProcessProtocol

class NativeProcessProtocol {

public:

  virtual ~NativeProcessProtocol() = default;

  typedef std::vector<std::unique_ptr<NativeThreadProtocol>> thread_collection;

  template <typename I>

  static NativeThreadProtocol &thread_list_adapter(I &iter) {

    assert(*iter);

    return **iter;

  }

  typedef LockingAdaptedIterable<thread_collection, NativeThreadProtocol &,

                                 thread_list_adapter, std::recursive_mutex>

      ThreadIterable;

  virtual Status Resume(const ResumeActionList &resume_actions) = 0;

  virtual Status Halt() = 0;

  virtual Status Detach() = 0;

  /// Sends a process a UNIX signal \a signal.

  ///

  /// \return

  ///     Returns an error object.

  virtual Status Signal(int signo) = 0;

  /// Tells a process to interrupt all operations as if by a Ctrl-C.

  ///

  /// The default implementation will send a local host's equivalent of

  /// a SIGSTOP to the process via the NativeProcessProtocol::Signal()

  /// operation.

  ///

  /// \return

  ///     Returns an error object.

  virtual Status Interrupt();

  virtual Status Kill() = 0;

  // Tells a process not to stop the inferior on given signals and just

  // reinject them back.

  virtual Status IgnoreSignals(llvm::ArrayRef<int> signals);

  // Memory and memory region functions

  virtual Status GetMemoryRegionInfo(lldb::addr_t load_addr,

                                     MemoryRegionInfo &range_info);

  virtual Status ReadMemory(lldb::addr_t addr, void *buf, size_t size,

                            size_t &bytes_read) = 0;

  Status ReadMemoryWithoutTrap(lldb::addr_t addr, void *buf, size_t size,

                               size_t &bytes_read);

  virtual Status ReadMemoryTags(int32_t type, lldb::addr_t addr, size_t len,

                                std::vector<uint8_t> &tags);

  virtual Status WriteMemoryTags(int32_t type, lldb::addr_t addr, size_t len,

                                 const std::vector<uint8_t> &tags);

  /// Reads a null terminated string from memory.

  ///

  /// Reads up to \p max_size bytes of memory until it finds a '\0'.

  /// If a '\0' is not found then it reads max_size-1 bytes as a string and a

  /// '\0' is added as the last character of the \p buffer.

  ///

  /// \param[in] addr

  ///     The address in memory to read from.

  ///

  /// \param[in] buffer

  ///     An allocated buffer with at least \p max_size size.

  ///

  /// \param[in] max_size

  ///     The maximum number of bytes to read from memory until it reads the

  ///     string.

  ///

  /// \param[out] total_bytes_read

  ///     The number of bytes read from memory into \p buffer.

  ///

  /// \return

  ///     Returns a StringRef backed up by the \p buffer passed in.

  llvm::Expected<llvm::StringRef>

  ReadCStringFromMemory(lldb::addr_t addr, char *buffer, size_t max_size,

                        size_t &total_bytes_read);

  virtual Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size,

                             size_t &bytes_written) = 0;

  virtual llvm::Expected<lldb::addr_t> AllocateMemory(size_t size,

                                                      uint32_t permissions) {

    return llvm::make_error<UnimplementedError>();

  }

  virtual llvm::Error DeallocateMemory(lldb::addr_t addr) {

    return llvm::make_error<UnimplementedError>();

  }

  virtual lldb::addr_t GetSharedLibraryInfoAddress() = 0;

  virtual llvm::Expected<std::vector<SVR4LibraryInfo>>

  GetLoadedSVR4Libraries() {

    return llvm::createStringError(llvm::inconvertibleErrorCode(),

                                   "Not implemented");

  }

  virtual bool IsAlive() const;

  virtual size_t UpdateThreads() = 0;

  virtual const ArchSpec &GetArchitecture() const = 0;

  // Breakpoint functions

  virtual Status SetBreakpoint(lldb::addr_t addr, uint32_t size,

                               bool hardware) = 0;

  virtual Status RemoveBreakpoint(lldb::addr_t addr, bool hardware = false);

  // Hardware Breakpoint functions

  virtual const HardwareBreakpointMap &GetHardwareBreakpointMap() const;

  virtual Status SetHardwareBreakpoint(lldb::addr_t addr, size_t size);

  virtual Status RemoveHardwareBreakpoint(lldb::addr_t addr);

  // Watchpoint functions

  virtual const NativeWatchpointList::WatchpointMap &GetWatchpointMap() const;

  virtual llvm::Optional<std::pair<uint32_t, uint32_t>>

  GetHardwareDebugSupportInfo() const;

  virtual Status SetWatchpoint(lldb::addr_t addr, size_t size,

                               uint32_t watch_flags, bool hardware);

  virtual Status RemoveWatchpoint(lldb::addr_t addr);

  // Accessors

  lldb::pid_t GetID() const { return m_pid; }

  lldb::StateType GetState() const;

  bool IsRunning() const {

    return m_state == lldb::eStateRunning || IsStepping();

  }

  bool IsStepping() const { return m_state == lldb::eStateStepping; }

  bool CanResume() const { return m_state == lldb::eStateStopped; }

  lldb::ByteOrder GetByteOrder() const {

    return GetArchitecture().GetByteOrder();

  }

  uint32_t GetAddressByteSize() const {

    return GetArchitecture().GetAddressByteSize();

  }

  virtual llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>

  GetAuxvData() const = 0;

  // Exit Status

  virtual llvm::Optional<WaitStatus> GetExitStatus();

  virtual bool SetExitStatus(WaitStatus status, bool bNotifyStateChange);

  // Access to threads

  NativeThreadProtocol *GetThreadAtIndex(uint32_t idx);

  NativeThreadProtocol *GetThreadByID(lldb::tid_t tid);

  void SetCurrentThreadID(lldb::tid_t tid) { m_current_thread_id = tid; }

  lldb::tid_t GetCurrentThreadID() const { return m_current_thread_id; }

  NativeThreadProtocol *GetCurrentThread() {

    return GetThreadByID(m_current_thread_id);

  }

  ThreadIterable Threads() const {

    return ThreadIterable(m_threads, m_threads_mutex);

  }

  // Access to inferior stdio

  virtual int GetTerminalFileDescriptor() { return m_terminal_fd; }

  // Stop id interface

  uint32_t GetStopID() const;

  // Callbacks for low-level process state changes

  class NativeDelegate {

  public:

    virtual ~NativeDelegate() = default;

    virtual void InitializeDelegate(NativeProcessProtocol *process) = 0;

    virtual void ProcessStateChanged(NativeProcessProtocol *process,

                                     lldb::StateType state) = 0;

    virtual void DidExec(NativeProcessProtocol *process) = 0;

    virtual void

    NewSubprocess(NativeProcessProtocol *parent_process,

                  std::unique_ptr<NativeProcessProtocol> child_process) = 0;

  };

  virtual Status GetLoadedModuleFileSpec(const char *module_path,

                                         FileSpec &file_spec) = 0;

  virtual Status GetFileLoadAddress(const llvm::StringRef &file_name,

                                    lldb::addr_t &load_addr) = 0;

  /// Extension flag constants, returned by Factory::GetSupportedExtensions()

  /// and passed to SetEnabledExtension()

  enum class Extension {

    multiprocess = (1u << 0),

    fork = (1u << 1),

    vfork = (1u << 2),

    pass_signals = (1u << 3),

    auxv = (1u << 4),

    libraries_svr4 = (1u << 5),

    memory_tagging = (1u << 6),

    savecore = (1u << 7),

    siginfo_read = (1u << 8),

    LLVM_MARK_AS_BITMASK_ENUM(siginfo_read)

  };

  class Factory {

  public:

    virtual ~Factory();

    /// Launch a process for debugging.

    ///

    /// \param[in] launch_info

    ///     Information required to launch the process.

    ///

    /// \param[in] native_delegate

    ///     The delegate that will receive messages regarding the

    ///     inferior.  Must outlive the NativeProcessProtocol

    ///     instance.

    ///

    /// \param[in] mainloop

    ///     The mainloop instance with which the process can register

    ///     callbacks. Must outlive the NativeProcessProtocol

    ///     instance.

    ///

    /// \return

    ///     A NativeProcessProtocol shared pointer if the operation succeeded or

    ///     an error object if it failed.

    virtual llvm::Expected<std::unique_ptr<NativeProcessProtocol>>

    Launch(ProcessLaunchInfo &launch_info, NativeDelegate &native_delegate,

           MainLoop &mainloop) const = 0;

    /// Attach to an existing process.

    ///

    /// \param[in] pid

    ///     pid of the process locatable

    ///

    /// \param[in] native_delegate

    ///     The delegate that will receive messages regarding the

    ///     inferior.  Must outlive the NativeProcessProtocol

    ///     instance.

    ///

    /// \param[in] mainloop

    ///     The mainloop instance with which the process can register

    ///     callbacks. Must outlive the NativeProcessProtocol

    ///     instance.

    ///

    /// \return

    ///     A NativeProcessProtocol shared pointer if the operation succeeded or

    ///     an error object if it failed.

    virtual llvm::Expected<std::unique_ptr<NativeProcessProtocol>>

    Attach(lldb::pid_t pid, NativeDelegate &native_delegate,

           MainLoop &mainloop) const = 0;

    /// Get the bitmask of extensions supported by this process plugin.

    ///

    /// \return

    ///     A NativeProcessProtocol::Extension bitmask.

    virtual Extension GetSupportedExtensions() const { return {}; }

  };

  /// Notify tracers that the target process will resume

  virtual void NotifyTracersProcessWillResume() {}

  /// Notify tracers that the target process just stopped

  virtual void NotifyTracersProcessDidStop() {}

  /// Start tracing a process or its threads.

  ///

  /// \param[in] json_params

  ///     JSON object with the information of what and how to trace.

  ///     In the case of gdb-remote, this object should conform to the

  ///     jLLDBTraceStart packet.

  ///

  ///     This object should have a string entry called "type", which is the

  ///     tracing technology name.

  ///

  /// \param[in] type

  ///     Tracing technology type, as described in the \a json_params.

  ///

  /// \return

  ///     \a llvm::Error::success if the operation was successful, or an

  ///     \a llvm::Error otherwise.

  virtual llvm::Error TraceStart(llvm::StringRef json_params,

                                 llvm::StringRef type) {

    return llvm::createStringError(llvm::inconvertibleErrorCode(),

                                   "Unsupported tracing type '%s'",

                                   type.data());

  }

  /// \copydoc Process::TraceStop(const TraceStopRequest &)

  virtual llvm::Error TraceStop(const TraceStopRequest &request) {

    return llvm::createStringError(llvm::inconvertibleErrorCode(),

                                   "Unsupported tracing type '%s'",

                                   request.type.data());

  }

  /// \copydoc Process::TraceGetState(llvm::StringRef type)

  virtual llvm::Expected<llvm::json::Value>

  TraceGetState(llvm::StringRef type) {

    return llvm::createStringError(llvm::inconvertibleErrorCode(),

                                   "Unsupported tracing type '%s'",

                                   type.data());

  }

  /// \copydoc Process::TraceGetBinaryData(const TraceGetBinaryDataRequest &)

  virtual llvm::Expected<std::vector<uint8_t>>

  TraceGetBinaryData(const TraceGetBinaryDataRequest &request) {

    return llvm::createStringError(

        llvm::inconvertibleErrorCode(),

        "Unsupported data kind '%s' for the '%s' tracing technology",

        request.kind.c_str(), request.type.c_str());

  }

  /// \copydoc Process::TraceSupported()

  virtual llvm::Expected<TraceSupportedResponse> TraceSupported() {

    return llvm::make_error<UnimplementedError>();

  }

  /// Method called in order to propagate the bitmap of protocol

  /// extensions supported by the client.

  ///

  /// \param[in] flags

  ///     The bitmap of enabled extensions.

  virtual void SetEnabledExtensions(Extension flags) {

    m_enabled_extensions = flags;

  }

  /// Write a core dump (without crashing the program).

  ///

  /// \param[in] path_hint

  ///     Suggested core dump path (optional, can be empty).

  ///

  /// \return

  ///     Path to the core dump if successfully written, an error

  ///     otherwise.

  virtual llvm::Expected<std::string> SaveCore(llvm::StringRef path_hint) {

    return llvm::createStringError(llvm::inconvertibleErrorCode(),

                                   "Not implemented");

  }

protected:

  struct SoftwareBreakpoint {

    uint32_t ref_count;

    llvm::SmallVector<uint8_t, 4> saved_opcodes;

    llvm::ArrayRef<uint8_t> breakpoint_opcodes;

  };

  std::unordered_map<lldb::addr_t, SoftwareBreakpoint> m_software_breakpoints;

  lldb::pid_t m_pid;

  std::vector<std::unique_ptr<NativeThreadProtocol>> m_threads;

  lldb::tid_t m_current_thread_id = LLDB_INVALID_THREAD_ID;

  mutable std::recursive_mutex m_threads_mutex;

  lldb::StateType m_state = lldb::eStateInvalid;

  mutable std::recursive_mutex m_state_mutex;

  llvm::Optional<WaitStatus> m_exit_status;

  NativeDelegate &m_delegate;

  NativeWatchpointList m_watchpoint_list;

  HardwareBreakpointMap m_hw_breakpoints_map;

  int m_terminal_fd;

  uint32_t m_stop_id = 0;

  // Set of signal numbers that LLDB directly injects back to inferior without

  // stopping it.

  llvm::DenseSet<int> m_signals_to_ignore;

  // Extensions enabled per the last SetEnabledExtensions() call.

  Extension m_enabled_extensions;

  // lldb_private::Host calls should be used to launch a process for debugging,

  // and then the process should be attached to. When attaching to a process

  // lldb_private::Host calls should be used to locate the process to attach

  // to, and then this function should be called.

  NativeProcessProtocol(lldb::pid_t pid, int terminal_fd,

                        NativeDelegate &delegate);

  void SetID(lldb::pid_t pid) { m_pid = pid; }

  // interface for state handling

  void SetState(lldb::StateType state, bool notify_delegates = true);

  // Derived classes need not implement this.  It can be used as a hook to

  // clear internal caches that should be invalidated when stop ids change.

  //

  // Note this function is called with the state mutex obtained by the caller.

  virtual void DoStopIDBumped(uint32_t newBumpId);

  // interface for software breakpoints

  Status SetSoftwareBreakpoint(lldb::addr_t addr, uint32_t size_hint);

  Status RemoveSoftwareBreakpoint(lldb::addr_t addr);

  virtual llvm::Expected<llvm::ArrayRef<uint8_t>>

  GetSoftwareBreakpointTrapOpcode(size_t size_hint);

  /// Return the offset of the PC relative to the software breakpoint that was hit. If an

  /// architecture (e.g. arm) reports breakpoint hits before incrementing the PC, this offset

  /// will be 0. If an architecture (e.g. intel) reports breakpoints hits after incrementing the

  /// PC, this offset will be the size of the breakpoint opcode.

  virtual size_t GetSoftwareBreakpointPCOffset();

  // Adjust the thread's PC after hitting a software breakpoint. On

  // architectures where the PC points after the breakpoint instruction, this

  // resets it to point to the breakpoint itself.

  void FixupBreakpointPCAsNeeded(NativeThreadProtocol &thread);

  /// Notify the delegate that an exec occurred.

  ///

  /// Provide a mechanism for a delegate to clear out any exec-

  /// sensitive data.

  virtual void NotifyDidExec();

  NativeThreadProtocol *GetThreadByIDUnlocked(lldb::tid_t tid);

private:

  void SynchronouslyNotifyProcessStateChanged(lldb::StateType state);

  llvm::Expected<SoftwareBreakpoint>

  EnableSoftwareBreakpoint(lldb::addr_t addr, uint32_t size_hint);

};

} // namespace lldb_private

#endif // LLDB_HOST_COMMON_NATIVEPROCESSPROTOCOL_H