Files
clang-p2996/lldb/source/Host/common/Terminal.cpp
2021-10-01 18:23:54 +02:00

162 lines
4.2 KiB
C++

//===-- Terminal.cpp ------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "lldb/Host/Terminal.h"
#include "lldb/Host/Config.h"
#include "lldb/Host/PosixApi.h"
#include "llvm/ADT/STLExtras.h"
#include <csignal>
#include <fcntl.h>
#if LLDB_ENABLE_TERMIOS
#include <termios.h>
#endif
using namespace lldb_private;
bool Terminal::IsATerminal() const { return m_fd >= 0 && ::isatty(m_fd); }
bool Terminal::SetEcho(bool enabled) {
if (FileDescriptorIsValid()) {
#if LLDB_ENABLE_TERMIOS
if (IsATerminal()) {
struct termios fd_termios;
if (::tcgetattr(m_fd, &fd_termios) == 0) {
bool set_corectly = false;
if (enabled) {
if (fd_termios.c_lflag & ECHO)
set_corectly = true;
else
fd_termios.c_lflag |= ECHO;
} else {
if (fd_termios.c_lflag & ECHO)
fd_termios.c_lflag &= ~ECHO;
else
set_corectly = true;
}
if (set_corectly)
return true;
return ::tcsetattr(m_fd, TCSANOW, &fd_termios) == 0;
}
}
#endif // #if LLDB_ENABLE_TERMIOS
}
return false;
}
bool Terminal::SetCanonical(bool enabled) {
if (FileDescriptorIsValid()) {
#if LLDB_ENABLE_TERMIOS
if (IsATerminal()) {
struct termios fd_termios;
if (::tcgetattr(m_fd, &fd_termios) == 0) {
bool set_corectly = false;
if (enabled) {
if (fd_termios.c_lflag & ICANON)
set_corectly = true;
else
fd_termios.c_lflag |= ICANON;
} else {
if (fd_termios.c_lflag & ICANON)
fd_termios.c_lflag &= ~ICANON;
else
set_corectly = true;
}
if (set_corectly)
return true;
return ::tcsetattr(m_fd, TCSANOW, &fd_termios) == 0;
}
}
#endif // #if LLDB_ENABLE_TERMIOS
}
return false;
}
struct TerminalState::Data {
#if LLDB_ENABLE_TERMIOS
struct termios m_termios; ///< Cached terminal state information.
#endif
};
TerminalState::TerminalState(Terminal term, bool save_process_group)
: m_tty(term) {
Save(term, save_process_group);
}
TerminalState::~TerminalState() { Restore(); }
void TerminalState::Clear() {
m_tty.Clear();
m_tflags = -1;
m_data.reset();
m_process_group = -1;
}
bool TerminalState::Save(Terminal term, bool save_process_group) {
Clear();
m_tty = term;
if (m_tty.IsATerminal()) {
int fd = m_tty.GetFileDescriptor();
#if LLDB_ENABLE_POSIX
m_tflags = ::fcntl(fd, F_GETFL, 0);
#if LLDB_ENABLE_TERMIOS
std::unique_ptr<Data> new_data{new Data()};
if (::tcgetattr(fd, &new_data->m_termios) == 0)
m_data = std::move(new_data);
#endif // LLDB_ENABLE_TERMIOS
if (save_process_group)
m_process_group = ::tcgetpgrp(fd);
#endif // LLDB_ENABLE_POSIX
}
return IsValid();
}
bool TerminalState::Restore() const {
#if LLDB_ENABLE_POSIX
if (IsValid()) {
const int fd = m_tty.GetFileDescriptor();
if (TFlagsIsValid())
fcntl(fd, F_SETFL, m_tflags);
#if LLDB_ENABLE_TERMIOS
if (TTYStateIsValid())
tcsetattr(fd, TCSANOW, &m_data->m_termios);
#endif // LLDB_ENABLE_TERMIOS
if (ProcessGroupIsValid()) {
// Save the original signal handler.
void (*saved_sigttou_callback)(int) = nullptr;
saved_sigttou_callback = (void (*)(int))signal(SIGTTOU, SIG_IGN);
// Set the process group
tcsetpgrp(fd, m_process_group);
// Restore the original signal handler.
signal(SIGTTOU, saved_sigttou_callback);
}
return true;
}
#endif // LLDB_ENABLE_POSIX
return false;
}
bool TerminalState::IsValid() const {
return m_tty.FileDescriptorIsValid() &&
(TFlagsIsValid() || TTYStateIsValid() || ProcessGroupIsValid());
}
bool TerminalState::TFlagsIsValid() const { return m_tflags != -1; }
bool TerminalState::TTYStateIsValid() const { return bool(m_data); }
bool TerminalState::ProcessGroupIsValid() const {
return static_cast<int32_t>(m_process_group) != -1;
}