1//===-- Terminal.h ----------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLDB_HOST_TERMINAL_H
10#define LLDB_HOST_TERMINAL_H
11
12#include "lldb/lldb-private.h"
13#include "llvm/Support/Error.h"
14
15namespace lldb_private {
16
17class TerminalState;
18
19class Terminal {
20public:
21 enum class Parity {
22 No,
23 Even,
24 Odd,
25 Space,
26 Mark,
27 };
28
29 enum class ParityCheck {
30 // No parity checking
31 No,
32 // Replace erraneous bytes with NUL
33 ReplaceWithNUL,
34 // Ignore erraneous bytes
35 Ignore,
36 // Mark erraneous bytes by prepending them with \xFF\x00; real \xFF
37 // is escaped to \xFF\xFF
38 Mark,
39 };
40
41 Terminal(int fd = -1) : m_fd(fd) {}
42
43 ~Terminal() = default;
44
45 bool IsATerminal() const;
46
47 int GetFileDescriptor() const { return m_fd; }
48
49 void SetFileDescriptor(int fd) { m_fd = fd; }
50
51 bool FileDescriptorIsValid() const { return m_fd != -1; }
52
53 void Clear() { m_fd = -1; }
54
55 llvm::Error SetEcho(bool enabled);
56
57 llvm::Error SetCanonical(bool enabled);
58
59 llvm::Error SetRaw();
60
61 llvm::Error SetBaudRate(unsigned int baud_rate);
62
63 llvm::Error SetStopBits(unsigned int stop_bits);
64
65 llvm::Error SetParity(Parity parity);
66
67 llvm::Error SetParityCheck(ParityCheck parity_check);
68
69 llvm::Error SetHardwareFlowControl(bool enabled);
70
71protected:
72 struct Data;
73
74 int m_fd; // This may or may not be a terminal file descriptor
75
76 llvm::Expected<Data> GetData();
77 llvm::Error SetData(const Data &data);
78
79 friend class TerminalState;
80};
81
82/// \class TerminalState Terminal.h "lldb/Host/Terminal.h"
83/// A RAII-friendly terminal state saving/restoring class.
84///
85/// This class can be used to remember the terminal state for a file
86/// descriptor and later restore that state as it originally was.
87class TerminalState {
88public:
89 /// Construct a new instance and optionally save terminal state.
90 ///
91 /// \param[in] term
92 /// The Terminal instance holding the file descriptor to save the state
93 /// of. If the instance is not associated with a fd, no state will
94 /// be saved.
95 ///
96 /// \param[in] save_process_group
97 /// If \b true, save the process group settings, else do not
98 /// save the process group settings for a TTY.
99 TerminalState(Terminal term = -1, bool save_process_group = false);
100
101 /// Destroy the instance, restoring terminal state if saved. If restoring
102 /// state is undesirable, the instance needs to be reset before destruction.
103 ~TerminalState();
104
105 /// Save the TTY state for \a fd.
106 ///
107 /// Save the current state of the TTY for the file descriptor "fd" and if
108 /// "save_process_group" is true, attempt to save the process group info for
109 /// the TTY.
110 ///
111 /// \param[in] term
112 /// The Terminal instance holding fd to save.
113 ///
114 /// \param[in] save_process_group
115 /// If \b true, save the process group settings, else do not
116 /// save the process group settings for a TTY.
117 ///
118 /// \return
119 /// Returns \b true if \a fd describes a TTY and if the state
120 /// was able to be saved, \b false otherwise.
121 bool Save(Terminal term, bool save_process_group);
122
123 /// Restore the TTY state to the cached state.
124 ///
125 /// Restore the state of the TTY using the cached values from a previous
126 /// call to TerminalState::Save(int,bool).
127 ///
128 /// \return
129 /// Returns \b true if the TTY state was successfully restored,
130 /// \b false otherwise.
131 bool Restore() const;
132
133 /// Test for valid cached TTY state information.
134 ///
135 /// \return
136 /// Returns \b true if this object has valid saved TTY state
137 /// settings that can be used to restore a previous state,
138 /// \b false otherwise.
139 bool IsValid() const;
140
141 void Clear();
142
143protected:
144 /// Test if tflags is valid.
145 ///
146 /// \return
147 /// Returns \b true if \a m_tflags is valid and can be restored,
148 /// \b false otherwise.
149 bool TFlagsIsValid() const;
150
151 /// Test if ttystate is valid.
152 ///
153 /// \return
154 /// Returns \b true if \a m_ttystate is valid and can be
155 /// restored, \b false otherwise.
156 bool TTYStateIsValid() const;
157
158 /// Test if the process group information is valid.
159 ///
160 /// \return
161 /// Returns \b true if \a m_process_group is valid and can be
162 /// restored, \b false otherwise.
163 bool ProcessGroupIsValid() const;
164
165 // Member variables
166 Terminal m_tty; ///< A terminal
167 int m_tflags = -1; ///< Cached tflags information.
168 std::unique_ptr<Terminal::Data> m_data; ///< Platform-specific implementation.
169 lldb::pid_t m_process_group = -1; ///< Cached process group information.
170};
171
172} // namespace lldb_private
173
174#endif // LLDB_HOST_TERMINAL_H
175

source code of lldb/include/lldb/Host/Terminal.h