llvm/lldb/source/Host/common/PseudoTerminal.cpp

//===-- PseudoTerminal.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/PseudoTerminal.h"
#include "lldb/Host/Config.h"
#include "lldb/Host/FileSystem.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Errno.h"
#include <cassert>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <mutex>
#if defined(TIOCSCTTY)
#include <sys/ioctl.h>
#endif

#include "lldb/Host/PosixApi.h"

#if defined(__APPLE__)
#include <Availability.h>
#endif

#if defined(__ANDROID__)
int posix_openpt(int flags);
#endif

usingnamespacelldb_private;

// PseudoTerminal constructor
PseudoTerminal::PseudoTerminal() = default;

// Destructor
//
// The destructor will close the primary and secondary file descriptors if they
// are valid and ownership has not been released using the
// ReleasePrimaryFileDescriptor() or the ReleaseSaveFileDescriptor() member
// functions.
PseudoTerminal::~PseudoTerminal() { … }

// Close the primary file descriptor if it is valid.
void PseudoTerminal::ClosePrimaryFileDescriptor() { … }

// Close the secondary file descriptor if it is valid.
void PseudoTerminal::CloseSecondaryFileDescriptor() { … }

llvm::Error PseudoTerminal::OpenFirstAvailablePrimary(int oflag) { … }

llvm::Error PseudoTerminal::OpenSecondary(int oflag) { … }

#if !HAVE_PTSNAME_R || defined(__APPLE__)
static std::string use_ptsname(int fd) {
  static std::mutex mutex;
  std::lock_guard<std::mutex> guard(mutex);
  const char *r = ptsname(fd);
  assert(r != nullptr);
  return r;
}
#endif

std::string PseudoTerminal::GetSecondaryName() const { … }

llvm::Expected<lldb::pid_t> PseudoTerminal::Fork() { … }

// The primary file descriptor accessor. This object retains ownership of the
// primary file descriptor when this accessor is used. Use
// ReleasePrimaryFileDescriptor() if you wish this object to release ownership
// of the primary file descriptor.
//
// Returns the primary file descriptor, or -1 if the primary file descriptor is
// not currently valid.
int PseudoTerminal::GetPrimaryFileDescriptor() const { … }

// The secondary file descriptor accessor.
//
// Returns the secondary file descriptor, or -1 if the secondary file descriptor
// is not currently valid.
int PseudoTerminal::GetSecondaryFileDescriptor() const { … }

// Release ownership of the primary pseudo terminal file descriptor without
// closing it. The destructor for this class will close the primary file
// descriptor if the ownership isn't released using this call and the primary
// file descriptor has been opened.
int PseudoTerminal::ReleasePrimaryFileDescriptor() { … }

// Release ownership of the secondary pseudo terminal file descriptor without
// closing it. The destructor for this class will close the secondary file
// descriptor if the ownership isn't released using this call and the secondary
// file descriptor has been opened.
int PseudoTerminal::ReleaseSecondaryFileDescriptor() { … }