1//===-- Terminal.cpp ------------------------------------------------------===//
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#include "lldb/Host/Terminal.h"
10
11#include "lldb/Host/Config.h"
12#include "lldb/Host/PosixApi.h"
13#include "llvm/ADT/STLExtras.h"
14
15#include <csignal>
16#include <fcntl.h>
17#include <optional>
18
19#if LLDB_ENABLE_TERMIOS
20#include <termios.h>
21#endif
22
23using namespace lldb_private;
24
25struct Terminal::Data {
26#if LLDB_ENABLE_TERMIOS
27 struct termios m_termios; ///< Cached terminal state information.
28#endif
29};
30
31bool Terminal::IsATerminal() const { return m_fd >= 0 && ::isatty(fd: m_fd); }
32
33#if !LLDB_ENABLE_TERMIOS
34static llvm::Error termiosMissingError() {
35 return llvm::createStringError(llvm::inconvertibleErrorCode(),
36 "termios support missing in LLDB");
37}
38#endif
39
40llvm::Expected<Terminal::Data> Terminal::GetData() {
41#if LLDB_ENABLE_TERMIOS
42 if (!FileDescriptorIsValid())
43 return llvm::createStringError(EC: llvm::inconvertibleErrorCode(),
44 S: "invalid fd");
45
46 if (!IsATerminal())
47 return llvm::createStringError(EC: llvm::inconvertibleErrorCode(),
48 S: "fd not a terminal");
49
50 Data data;
51 if (::tcgetattr(fd: m_fd, termios_p: &data.m_termios) != 0)
52 return llvm::createStringError(
53 EC: std::error_code(errno, std::generic_category()),
54 S: "unable to get teletype attributes");
55 return data;
56#else // !LLDB_ENABLE_TERMIOS
57 return termiosMissingError();
58#endif // LLDB_ENABLE_TERMIOS
59}
60
61llvm::Error Terminal::SetData(const Terminal::Data &data) {
62#if LLDB_ENABLE_TERMIOS
63 assert(FileDescriptorIsValid());
64 assert(IsATerminal());
65
66 if (::tcsetattr(fd: m_fd, TCSANOW, termios_p: &data.m_termios) != 0)
67 return llvm::createStringError(
68 EC: std::error_code(errno, std::generic_category()),
69 S: "unable to set teletype attributes");
70 return llvm::Error::success();
71#else // !LLDB_ENABLE_TERMIOS
72 return termiosMissingError();
73#endif // LLDB_ENABLE_TERMIOS
74}
75
76llvm::Error Terminal::SetEcho(bool enabled) {
77#if LLDB_ENABLE_TERMIOS
78 llvm::Expected<Data> data = GetData();
79 if (!data)
80 return data.takeError();
81
82 struct termios &fd_termios = data->m_termios;
83 fd_termios.c_lflag &= ~ECHO;
84 if (enabled)
85 fd_termios.c_lflag |= ECHO;
86 return SetData(data.get());
87#else // !LLDB_ENABLE_TERMIOS
88 return termiosMissingError();
89#endif // LLDB_ENABLE_TERMIOS
90}
91
92llvm::Error Terminal::SetCanonical(bool enabled) {
93#if LLDB_ENABLE_TERMIOS
94 llvm::Expected<Data> data = GetData();
95 if (!data)
96 return data.takeError();
97
98 struct termios &fd_termios = data->m_termios;
99 fd_termios.c_lflag &= ~ICANON;
100 if (enabled)
101 fd_termios.c_lflag |= ICANON;
102 return SetData(data.get());
103#else // !LLDB_ENABLE_TERMIOS
104 return termiosMissingError();
105#endif // LLDB_ENABLE_TERMIOS
106}
107
108llvm::Error Terminal::SetRaw() {
109#if LLDB_ENABLE_TERMIOS
110 llvm::Expected<Data> data = GetData();
111 if (!data)
112 return data.takeError();
113
114 struct termios &fd_termios = data->m_termios;
115 ::cfmakeraw(termios_p: &fd_termios);
116
117 // Make sure only one character is needed to return from a read
118 // (cfmakeraw() doesn't do this on NetBSD)
119 fd_termios.c_cc[VMIN] = 1;
120 fd_termios.c_cc[VTIME] = 0;
121
122 return SetData(data.get());
123#else // !LLDB_ENABLE_TERMIOS
124 return termiosMissingError();
125#endif // LLDB_ENABLE_TERMIOS
126}
127
128#if LLDB_ENABLE_TERMIOS
129static std::optional<speed_t> baudRateToConst(unsigned int baud_rate) {
130 switch (baud_rate) {
131#if defined(B50)
132 case 50:
133 return B50;
134#endif
135#if defined(B75)
136 case 75:
137 return B75;
138#endif
139#if defined(B110)
140 case 110:
141 return B110;
142#endif
143#if defined(B134)
144 case 134:
145 return B134;
146#endif
147#if defined(B150)
148 case 150:
149 return B150;
150#endif
151#if defined(B200)
152 case 200:
153 return B200;
154#endif
155#if defined(B300)
156 case 300:
157 return B300;
158#endif
159#if defined(B600)
160 case 600:
161 return B600;
162#endif
163#if defined(B1200)
164 case 1200:
165 return B1200;
166#endif
167#if defined(B1800)
168 case 1800:
169 return B1800;
170#endif
171#if defined(B2400)
172 case 2400:
173 return B2400;
174#endif
175#if defined(B4800)
176 case 4800:
177 return B4800;
178#endif
179#if defined(B9600)
180 case 9600:
181 return B9600;
182#endif
183#if defined(B19200)
184 case 19200:
185 return B19200;
186#endif
187#if defined(B38400)
188 case 38400:
189 return B38400;
190#endif
191#if defined(B57600)
192 case 57600:
193 return B57600;
194#endif
195#if defined(B115200)
196 case 115200:
197 return B115200;
198#endif
199#if defined(B230400)
200 case 230400:
201 return B230400;
202#endif
203#if defined(B460800)
204 case 460800:
205 return B460800;
206#endif
207#if defined(B500000)
208 case 500000:
209 return B500000;
210#endif
211#if defined(B576000)
212 case 576000:
213 return B576000;
214#endif
215#if defined(B921600)
216 case 921600:
217 return B921600;
218#endif
219#if defined(B1000000)
220 case 1000000:
221 return B1000000;
222#endif
223#if defined(B1152000)
224 case 1152000:
225 return B1152000;
226#endif
227#if defined(B1500000)
228 case 1500000:
229 return B1500000;
230#endif
231#if defined(B2000000)
232 case 2000000:
233 return B2000000;
234#endif
235#if defined(B76800)
236 case 76800:
237 return B76800;
238#endif
239#if defined(B153600)
240 case 153600:
241 return B153600;
242#endif
243#if defined(B307200)
244 case 307200:
245 return B307200;
246#endif
247#if defined(B614400)
248 case 614400:
249 return B614400;
250#endif
251#if defined(B2500000)
252 case 2500000:
253 return B2500000;
254#endif
255#if defined(B3000000)
256 case 3000000:
257 return B3000000;
258#endif
259#if defined(B3500000)
260 case 3500000:
261 return B3500000;
262#endif
263#if defined(B4000000)
264 case 4000000:
265 return B4000000;
266#endif
267 default:
268 return std::nullopt;
269 }
270}
271#endif
272
273llvm::Error Terminal::SetBaudRate(unsigned int baud_rate) {
274#if LLDB_ENABLE_TERMIOS
275 llvm::Expected<Data> data = GetData();
276 if (!data)
277 return data.takeError();
278
279 struct termios &fd_termios = data->m_termios;
280 std::optional<speed_t> val = baudRateToConst(baud_rate);
281 if (!val) // invalid value
282 return llvm::createStringError(EC: llvm::inconvertibleErrorCode(),
283 Fmt: "baud rate %d unsupported by the platform",
284 Vals: baud_rate);
285 if (::cfsetispeed(termios_p: &fd_termios, speed: *val) != 0)
286 return llvm::createStringError(
287 EC: std::error_code(errno, std::generic_category()),
288 S: "setting input baud rate failed");
289 if (::cfsetospeed(termios_p: &fd_termios, speed: *val) != 0)
290 return llvm::createStringError(
291 EC: std::error_code(errno, std::generic_category()),
292 S: "setting output baud rate failed");
293 return SetData(data.get());
294#else // !LLDB_ENABLE_TERMIOS
295 return termiosMissingError();
296#endif // LLDB_ENABLE_TERMIOS
297}
298
299llvm::Error Terminal::SetStopBits(unsigned int stop_bits) {
300#if LLDB_ENABLE_TERMIOS
301 llvm::Expected<Data> data = GetData();
302 if (!data)
303 return data.takeError();
304
305 struct termios &fd_termios = data->m_termios;
306 switch (stop_bits) {
307 case 1:
308 fd_termios.c_cflag &= ~CSTOPB;
309 break;
310 case 2:
311 fd_termios.c_cflag |= CSTOPB;
312 break;
313 default:
314 return llvm::createStringError(
315 EC: llvm::inconvertibleErrorCode(),
316 Fmt: "invalid stop bit count: %d (must be 1 or 2)", Vals: stop_bits);
317 }
318 return SetData(data.get());
319#else // !LLDB_ENABLE_TERMIOS
320 return termiosMissingError();
321#endif // LLDB_ENABLE_TERMIOS
322}
323
324llvm::Error Terminal::SetParity(Terminal::Parity parity) {
325#if LLDB_ENABLE_TERMIOS
326 llvm::Expected<Data> data = GetData();
327 if (!data)
328 return data.takeError();
329
330 struct termios &fd_termios = data->m_termios;
331 fd_termios.c_cflag &= ~(
332#if defined(CMSPAR)
333 CMSPAR |
334#endif
335 PARENB | PARODD);
336
337 if (parity != Parity::No) {
338 fd_termios.c_cflag |= PARENB;
339 if (parity == Parity::Odd || parity == Parity::Mark)
340 fd_termios.c_cflag |= PARODD;
341 if (parity == Parity::Mark || parity == Parity::Space) {
342#if defined(CMSPAR)
343 fd_termios.c_cflag |= CMSPAR;
344#else
345 return llvm::createStringError(
346 llvm::inconvertibleErrorCode(),
347 "space/mark parity is not supported by the platform");
348#endif
349 }
350 }
351 return SetData(data.get());
352#else // !LLDB_ENABLE_TERMIOS
353 return termiosMissingError();
354#endif // LLDB_ENABLE_TERMIOS
355}
356
357llvm::Error Terminal::SetParityCheck(Terminal::ParityCheck parity_check) {
358#if LLDB_ENABLE_TERMIOS
359 llvm::Expected<Data> data = GetData();
360 if (!data)
361 return data.takeError();
362
363 struct termios &fd_termios = data->m_termios;
364 fd_termios.c_iflag &= ~(IGNPAR | PARMRK | INPCK);
365
366 if (parity_check != ParityCheck::No) {
367 fd_termios.c_iflag |= INPCK;
368 if (parity_check == ParityCheck::Ignore)
369 fd_termios.c_iflag |= IGNPAR;
370 else if (parity_check == ParityCheck::Mark)
371 fd_termios.c_iflag |= PARMRK;
372 }
373 return SetData(data.get());
374#else // !LLDB_ENABLE_TERMIOS
375 return termiosMissingError();
376#endif // LLDB_ENABLE_TERMIOS
377}
378
379llvm::Error Terminal::SetHardwareFlowControl(bool enabled) {
380#if LLDB_ENABLE_TERMIOS
381 llvm::Expected<Data> data = GetData();
382 if (!data)
383 return data.takeError();
384
385#if defined(CRTSCTS)
386 struct termios &fd_termios = data->m_termios;
387 fd_termios.c_cflag &= ~CRTSCTS;
388 if (enabled)
389 fd_termios.c_cflag |= CRTSCTS;
390 return SetData(data.get());
391#else // !defined(CRTSCTS)
392 if (enabled)
393 return llvm::createStringError(
394 llvm::inconvertibleErrorCode(),
395 "hardware flow control is not supported by the platform");
396 return llvm::Error::success();
397#endif // defined(CRTSCTS)
398#else // !LLDB_ENABLE_TERMIOS
399 return termiosMissingError();
400#endif // LLDB_ENABLE_TERMIOS
401}
402
403TerminalState::TerminalState(Terminal term, bool save_process_group)
404 : m_tty(term) {
405 Save(term, save_process_group);
406}
407
408TerminalState::~TerminalState() { Restore(); }
409
410void TerminalState::Clear() {
411 m_tty.Clear();
412 m_tflags = -1;
413 m_data.reset();
414 m_process_group = -1;
415}
416
417bool TerminalState::Save(Terminal term, bool save_process_group) {
418 Clear();
419 m_tty = term;
420 if (m_tty.IsATerminal()) {
421#if LLDB_ENABLE_POSIX
422 int fd = m_tty.GetFileDescriptor();
423 m_tflags = ::fcntl(fd: fd, F_GETFL, 0);
424#if LLDB_ENABLE_TERMIOS
425 std::unique_ptr<Terminal::Data> new_data{new Terminal::Data()};
426 if (::tcgetattr(fd: fd, termios_p: &new_data->m_termios) == 0)
427 m_data = std::move(new_data);
428#endif // LLDB_ENABLE_TERMIOS
429 if (save_process_group)
430 m_process_group = ::tcgetpgrp(fd: fd);
431#endif // LLDB_ENABLE_POSIX
432 }
433 return IsValid();
434}
435
436bool TerminalState::Restore() const {
437#if LLDB_ENABLE_POSIX
438 if (IsValid()) {
439 const int fd = m_tty.GetFileDescriptor();
440 if (TFlagsIsValid())
441 fcntl(fd: fd, F_SETFL, m_tflags);
442
443#if LLDB_ENABLE_TERMIOS
444 if (TTYStateIsValid())
445 tcsetattr(fd: fd, TCSANOW, termios_p: &m_data->m_termios);
446#endif // LLDB_ENABLE_TERMIOS
447
448 if (ProcessGroupIsValid()) {
449 // Save the original signal handler.
450 void (*saved_sigttou_callback)(int) = nullptr;
451 saved_sigttou_callback = (void (*)(int))signal(SIGTTOU, SIG_IGN);
452 // Set the process group
453 tcsetpgrp(fd: fd, pgrp_id: m_process_group);
454 // Restore the original signal handler.
455 signal(SIGTTOU, handler: saved_sigttou_callback);
456 }
457 return true;
458 }
459#endif // LLDB_ENABLE_POSIX
460 return false;
461}
462
463bool TerminalState::IsValid() const {
464 return m_tty.FileDescriptorIsValid() &&
465 (TFlagsIsValid() || TTYStateIsValid() || ProcessGroupIsValid());
466}
467
468bool TerminalState::TFlagsIsValid() const { return m_tflags != -1; }
469
470bool TerminalState::TTYStateIsValid() const { return bool(m_data); }
471
472bool TerminalState::ProcessGroupIsValid() const {
473 return static_cast<int32_t>(m_process_group) != -1;
474}
475

source code of lldb/source/Host/common/Terminal.cpp