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diff --git a/gnu/llvm/lldb/tools/debugserver/source/PseudoTerminal.cpp b/gnu/llvm/lldb/tools/debugserver/source/PseudoTerminal.cpp
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+//===-- PseudoTerminal.cpp --------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Created by Greg Clayton on 1/8/08.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PseudoTerminal.h"
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+// PseudoTerminal constructor
+PseudoTerminal::PseudoTerminal()
+ : m_master_fd(invalid_fd), m_slave_fd(invalid_fd) {}
+
+// Destructor
+// The master and slave file descriptors will get closed if they are
+// valid. Call the ReleaseMasterFD()/ReleaseSlaveFD() member functions
+// to release any file descriptors that are needed beyond the lifespan
+// of this object.
+PseudoTerminal::~PseudoTerminal() {
+ CloseMaster();
+ CloseSlave();
+}
+
+// Close the master file descriptor if it is valid.
+void PseudoTerminal::CloseMaster() {
+ if (m_master_fd > 0) {
+ ::close(m_master_fd);
+ m_master_fd = invalid_fd;
+ }
+}
+
+// Close the slave file descriptor if it is valid.
+void PseudoTerminal::CloseSlave() {
+ if (m_slave_fd > 0) {
+ ::close(m_slave_fd);
+ m_slave_fd = invalid_fd;
+ }
+}
+
+// Open the first available pseudo terminal with OFLAG as the
+// permissions. The file descriptor is store in the m_master_fd member
+// variable and can be accessed via the MasterFD() or ReleaseMasterFD()
+// accessors.
+//
+// Suggested value for oflag is O_RDWR|O_NOCTTY
+//
+// RETURNS:
+// Zero when successful, non-zero indicating an error occurred.
+PseudoTerminal::Status PseudoTerminal::OpenFirstAvailableMaster(int oflag) {
+ // Open the master side of a pseudo terminal
+ m_master_fd = ::posix_openpt(oflag);
+ if (m_master_fd < 0) {
+ return err_posix_openpt_failed;
+ }
+
+ // Grant access to the slave pseudo terminal
+ if (::grantpt(m_master_fd) < 0) {
+ CloseMaster();
+ return err_grantpt_failed;
+ }
+
+ // Clear the lock flag on the slave pseudo terminal
+ if (::unlockpt(m_master_fd) < 0) {
+ CloseMaster();
+ return err_unlockpt_failed;
+ }
+
+ return success;
+}
+
+// Open the slave pseudo terminal for the current master pseudo
+// terminal. A master pseudo terminal should already be valid prior to
+// calling this function (see PseudoTerminal::OpenFirstAvailableMaster()).
+// The file descriptor is stored in the m_slave_fd member variable and
+// can be accessed via the SlaveFD() or ReleaseSlaveFD() accessors.
+//
+// RETURNS:
+// Zero when successful, non-zero indicating an error occurred.
+PseudoTerminal::Status PseudoTerminal::OpenSlave(int oflag) {
+ CloseSlave();
+
+ // Open the master side of a pseudo terminal
+ const char *slave_name = SlaveName();
+
+ if (slave_name == NULL)
+ return err_ptsname_failed;
+
+ m_slave_fd = ::open(slave_name, oflag);
+
+ if (m_slave_fd < 0)
+ return err_open_slave_failed;
+
+ return success;
+}
+
+// Get the name of the slave pseudo terminal. A master pseudo terminal
+// should already be valid prior to calling this function (see
+// PseudoTerminal::OpenFirstAvailableMaster()).
+//
+// RETURNS:
+// NULL if no valid master pseudo terminal or if ptsname() fails.
+// The name of the slave pseudo terminal as a NULL terminated C string
+// that comes from static memory, so a copy of the string should be
+// made as subsequent calls can change this value.
+const char *PseudoTerminal::SlaveName() const {
+ if (m_master_fd < 0)
+ return NULL;
+ return ::ptsname(m_master_fd);
+}
+
+// Fork a child process that and have its stdio routed to a pseudo
+// terminal.
+//
+// In the parent process when a valid pid is returned, the master file
+// descriptor can be used as a read/write access to stdio of the
+// child process.
+//
+// In the child process the stdin/stdout/stderr will already be routed
+// to the slave pseudo terminal and the master file descriptor will be
+// closed as it is no longer needed by the child process.
+//
+// This class will close the file descriptors for the master/slave
+// when the destructor is called, so be sure to call ReleaseMasterFD()
+// or ReleaseSlaveFD() if any file descriptors are going to be used
+// past the lifespan of this object.
+//
+// RETURNS:
+// in the parent process: the pid of the child, or -1 if fork fails
+// in the child process: zero
+
+pid_t PseudoTerminal::Fork(PseudoTerminal::Status &error) {
+ pid_t pid = invalid_pid;
+ error = OpenFirstAvailableMaster(O_RDWR | O_NOCTTY);
+
+ if (error == 0) {
+ // Successfully opened our master pseudo terminal
+
+ pid = ::fork();
+ if (pid < 0) {
+ // Fork failed
+ error = err_fork_failed;
+ } else if (pid == 0) {
+ // Child Process
+ ::setsid();
+
+ error = OpenSlave(O_RDWR);
+ if (error == 0) {
+ // Successfully opened slave
+ // We are done with the master in the child process so lets close it
+ CloseMaster();
+
+#if defined(TIOCSCTTY)
+ // Acquire the controlling terminal
+ if (::ioctl(m_slave_fd, TIOCSCTTY, (char *)0) < 0)
+ error = err_failed_to_acquire_controlling_terminal;
+#endif
+ // Duplicate all stdio file descriptors to the slave pseudo terminal
+ if (::dup2(m_slave_fd, STDIN_FILENO) != STDIN_FILENO)
+ error = error ? error : err_dup2_failed_on_stdin;
+ if (::dup2(m_slave_fd, STDOUT_FILENO) != STDOUT_FILENO)
+ error = error ? error : err_dup2_failed_on_stdout;
+ if (::dup2(m_slave_fd, STDERR_FILENO) != STDERR_FILENO)
+ error = error ? error : err_dup2_failed_on_stderr;
+ }
+ } else {
+ // Parent Process
+ // Do nothing and let the pid get returned!
+ }
+ }
+ return pid;
+}