--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/src/unix/tty.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,510 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv.h"
+#include "internal.h"
+
+#include <stdatomic.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <unistd.h>
+#include <termios.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+
+#if defined(__MVS__) && !defined(IMAXBEL)
+#define IMAXBEL 0
+#endif
+
+#if defined(__PASE__)
+/* On IBM i PASE, for better compatibility with running interactive programs in
+ * a 5250 environment, isatty() will return true for the stdin/stdout/stderr
+ * streams created by QSH/QP2TERM.
+ *
+ * For more, see docs on PASE_STDIO_ISATTY in
+ * https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/apis/pase_environ.htm
+ *
+ * This behavior causes problems for Node as it expects that if isatty() returns
+ * true that TTY ioctls will be supported by that fd (which is not an
+ * unreasonable expectation) and when they don't it crashes with assertion
+ * errors.
+ *
+ * Here, we create our own version of isatty() that uses ioctl() to identify
+ * whether the fd is *really* a TTY or not.
+ */
+static int isreallyatty(int file) {
+  int rc;
+ 
+  rc = !ioctl(file, TXISATTY + 0x81, NULL);
+  if (!rc && errno != EBADF)
+      errno = ENOTTY;
+
+  return rc;
+}
+#define isatty(fd) isreallyatty(fd)
+#endif
+
+static int orig_termios_fd = -1;
+static struct termios orig_termios;
+static _Atomic int termios_spinlock;
+
+int uv__tcsetattr(int fd, int how, const struct termios *term) {
+  int rc;
+
+  do
+    rc = tcsetattr(fd, how, term);
+  while (rc == -1 && errno == EINTR);
+
+  if (rc == -1)
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+static int uv__tty_is_slave(const int fd) {
+  int result;
+#if defined(__linux__) || defined(__FreeBSD__)
+  int dummy;
+
+  result = ioctl(fd, TIOCGPTN, &dummy) != 0;
+#elif defined(__APPLE__)
+  char dummy[256];
+
+  result = ioctl(fd, TIOCPTYGNAME, &dummy) != 0;
+#elif defined(__NetBSD__)
+  /*
+   * NetBSD as an extension returns with ptsname(3) and ptsname_r(3) the slave
+   * device name for both descriptors, the master one and slave one.
+   *
+   * Implement function to compare major device number with pts devices.
+   *
+   * The major numbers are machine-dependent, on NetBSD/amd64 they are
+   * respectively:
+   *  - master tty: ptc - major 6
+   *  - slave tty:  pts - major 5
+   */
+
+  struct stat sb;
+  /* Lookup device's major for the pts driver and cache it. */
+  static devmajor_t pts = NODEVMAJOR;
+
+  if (pts == NODEVMAJOR) {
+    pts = getdevmajor("pts", S_IFCHR);
+    if (pts == NODEVMAJOR)
+      abort();
+  }
+
+  /* Lookup stat structure behind the file descriptor. */
+  if (uv__fstat(fd, &sb) != 0)
+    abort();
+
+  /* Assert character device. */
+  if (!S_ISCHR(sb.st_mode))
+    abort();
+
+  /* Assert valid major. */
+  if (major(sb.st_rdev) == NODEVMAJOR)
+    abort();
+
+  result = (pts == major(sb.st_rdev));
+#else
+  /* Fallback to ptsname
+   */
+  result = ptsname(fd) == NULL;
+#endif
+  return result;
+}
+
+int uv_tty_init(uv_loop_t* loop, uv_tty_t* tty, int fd, int unused) {
+  uv_handle_type type;
+  int flags;
+  int newfd;
+  int r;
+  int saved_flags;
+  int mode;
+  char path[256];
+  (void)unused; /* deprecated parameter is no longer needed */
+
+  /* File descriptors that refer to files cannot be monitored with epoll.
+   * That restriction also applies to character devices like /dev/random
+   * (but obviously not /dev/tty.)
+   */
+  type = uv_guess_handle(fd);
+  if (type == UV_FILE || type == UV_UNKNOWN_HANDLE)
+    return UV_EINVAL;
+
+  flags = 0;
+  newfd = -1;
+
+  /* Save the fd flags in case we need to restore them due to an error. */
+  do
+    saved_flags = fcntl(fd, F_GETFL);
+  while (saved_flags == -1 && errno == EINTR);
+
+  if (saved_flags == -1)
+    return UV__ERR(errno);
+  mode = saved_flags & O_ACCMODE;
+
+  /* Reopen the file descriptor when it refers to a tty. This lets us put the
+   * tty in non-blocking mode without affecting other processes that share it
+   * with us.
+   *
+   * Example: `node | cat` - if we put our fd 0 in non-blocking mode, it also
+   * affects fd 1 of `cat` because both file descriptors refer to the same
+   * struct file in the kernel. When we reopen our fd 0, it points to a
+   * different struct file, hence changing its properties doesn't affect
+   * other processes.
+   */
+  if (type == UV_TTY) {
+    /* Reopening a pty in master mode won't work either because the reopened
+     * pty will be in slave mode (*BSD) or reopening will allocate a new
+     * master/slave pair (Linux). Therefore check if the fd points to a
+     * slave device.
+     */
+    if (uv__tty_is_slave(fd) && ttyname_r(fd, path, sizeof(path)) == 0)
+      r = uv__open_cloexec(path, mode | O_NOCTTY);
+    else
+      r = -1;
+
+    if (r < 0) {
+      /* fallback to using blocking writes */
+      if (mode != O_RDONLY)
+        flags |= UV_HANDLE_BLOCKING_WRITES;
+      goto skip;
+    }
+
+    newfd = r;
+
+    r = uv__dup2_cloexec(newfd, fd);
+    if (r < 0 && r != UV_EINVAL) {
+      /* EINVAL means newfd == fd which could conceivably happen if another
+       * thread called close(fd) between our calls to isatty() and open().
+       * That's a rather unlikely event but let's handle it anyway.
+       */
+      uv__close(newfd);
+      return r;
+    }
+
+    fd = newfd;
+  }
+
+skip:
+  uv__stream_init(loop, (uv_stream_t*) tty, UV_TTY);
+
+  /* If anything fails beyond this point we need to remove the handle from
+   * the handle queue, since it was added by uv__handle_init in uv_stream_init.
+   */
+
+  if (!(flags & UV_HANDLE_BLOCKING_WRITES))
+    uv__nonblock(fd, 1);
+
+#if defined(__APPLE__)
+  r = uv__stream_try_select((uv_stream_t*) tty, &fd);
+  if (r) {
+    int rc = r;
+    if (newfd != -1)
+      uv__close(newfd);
+    uv__queue_remove(&tty->handle_queue);
+    do
+      r = fcntl(fd, F_SETFL, saved_flags);
+    while (r == -1 && errno == EINTR);
+    return rc;
+  }
+#endif
+
+  if (mode != O_WRONLY)
+    flags |= UV_HANDLE_READABLE;
+  if (mode != O_RDONLY)
+    flags |= UV_HANDLE_WRITABLE;
+
+  uv__stream_open((uv_stream_t*) tty, fd, flags);
+  tty->mode = UV_TTY_MODE_NORMAL;
+
+  return 0;
+}
+
+static void uv__tty_make_raw(struct termios* tio) {
+  assert(tio != NULL);
+
+#if defined __sun || defined __MVS__
+  /*
+   * This implementation of cfmakeraw for Solaris and derivatives is taken from
+   * http://www.perkin.org.uk/posts/solaris-portability-cfmakeraw.html.
+   */
+  tio->c_iflag &= ~(IMAXBEL | IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR |
+                    IGNCR | ICRNL | IXON);
+  tio->c_oflag &= ~OPOST;
+  tio->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+  tio->c_cflag &= ~(CSIZE | PARENB);
+  tio->c_cflag |= CS8;
+
+  /*
+   * By default, most software expects a pending read to block until at
+   * least one byte becomes available.  As per termio(7I), this requires
+   * setting the MIN and TIME parameters appropriately.
+   *
+   * As a somewhat unfortunate artifact of history, the MIN and TIME slots
+   * in the control character array overlap with the EOF and EOL slots used
+   * for canonical mode processing.  Because the EOF character needs to be
+   * the ASCII EOT value (aka Control-D), it has the byte value 4.  When
+   * switching to raw mode, this is interpreted as a MIN value of 4; i.e.,
+   * reads will block until at least four bytes have been input.
+   *
+   * Other platforms with a distinct MIN slot like Linux and FreeBSD appear
+   * to default to a MIN value of 1, so we'll force that value here:
+   */
+  tio->c_cc[VMIN] = 1;
+  tio->c_cc[VTIME] = 0;
+#else
+  cfmakeraw(tio);
+#endif /* #ifdef __sun */
+}
+
+int uv_tty_set_mode(uv_tty_t* tty, uv_tty_mode_t mode) {
+  struct termios tmp;
+  int expected;
+  int fd;
+  int rc;
+
+  if (uv__is_raw_tty_mode(mode)) {
+    /* There is only a single raw TTY mode on UNIX. */
+    mode = UV_TTY_MODE_RAW;
+  }
+
+  if (tty->mode == (int) mode)
+    return 0;
+
+  fd = uv__stream_fd(tty);
+  if (tty->mode == UV_TTY_MODE_NORMAL && mode != UV_TTY_MODE_NORMAL) {
+    do
+      rc = tcgetattr(fd, &tty->orig_termios);
+    while (rc == -1 && errno == EINTR);
+
+    if (rc == -1)
+      return UV__ERR(errno);
+
+    /* This is used for uv_tty_reset_mode() */
+    do
+      expected = 0;
+    while (!atomic_compare_exchange_strong(&termios_spinlock, &expected, 1));
+
+    if (orig_termios_fd == -1) {
+      orig_termios = tty->orig_termios;
+      orig_termios_fd = fd;
+    }
+
+    atomic_store(&termios_spinlock, 0);
+  }
+
+  tmp = tty->orig_termios;
+  switch (mode) {
+    case UV_TTY_MODE_NORMAL:
+      break;
+    case UV_TTY_MODE_RAW:
+      tmp.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+      tmp.c_oflag |= (ONLCR);
+      tmp.c_cflag |= (CS8);
+      tmp.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+      tmp.c_cc[VMIN] = 1;
+      tmp.c_cc[VTIME] = 0;
+      break;
+    case UV_TTY_MODE_IO:
+      uv__tty_make_raw(&tmp);
+      break;
+    default:
+      UNREACHABLE();
+  }
+
+  /* Apply changes after draining */
+  rc = uv__tcsetattr(fd, TCSADRAIN, &tmp);
+  if (rc == 0)
+    tty->mode = mode;
+
+  return rc;
+}
+
+
+void uv__tty_close(uv_tty_t* handle) {
+  int expected;
+  int fd;
+
+  fd = handle->io_watcher.fd;
+  if (fd == -1)
+    goto done;
+
+  /* This is used for uv_tty_reset_mode() */
+  do
+    expected = 0;
+  while (!atomic_compare_exchange_strong(&termios_spinlock, &expected, 1));
+
+  if (fd == orig_termios_fd) {
+    /* XXX(bnoordhuis) the tcsetattr is probably wrong when there are still
+     * other uv_tty_t handles active that refer to the same tty/pty but it's
+     * hard to recognize that particular situation without maintaining some
+     * kind of process-global data structure, and that still won't work in a
+     * multi-process setup.
+     */
+    uv__tcsetattr(fd, TCSANOW, &orig_termios);
+    orig_termios_fd = -1;
+  }
+
+  atomic_store(&termios_spinlock, 0);
+
+done:
+  uv__stream_close((uv_stream_t*) handle);
+}
+
+
+int uv_tty_get_winsize(uv_tty_t* tty, int* width, int* height) {
+  struct winsize ws;
+  int err;
+
+  do
+    err = ioctl(uv__stream_fd(tty), TIOCGWINSZ, &ws);
+  while (err == -1 && errno == EINTR);
+
+  if (err == -1)
+    return UV__ERR(errno);
+
+  *width = ws.ws_col;
+  *height = ws.ws_row;
+
+  return 0;
+}
+
+
+uv_handle_type uv_guess_handle(uv_file file) {
+  struct sockaddr_storage ss;
+  struct stat s;
+  socklen_t len;
+  int type;
+
+  if (file < 0)
+    return UV_UNKNOWN_HANDLE;
+
+  if (isatty(file))
+    return UV_TTY;
+
+  if (uv__fstat(file, &s)) {
+#if defined(__PASE__)
+    /* On ibmi receiving RST from TCP instead of FIN immediately puts fd into
+     * an error state. fstat will return EINVAL, getsockname will also return
+     * EINVAL, even if sockaddr_storage is valid. (If file does not refer to a
+     * socket, ENOTSOCK is returned instead.)
+     * In such cases, we will permit the user to open the connection as uv_tcp
+     * still, so that the user can get immediately notified of the error in
+     * their read callback and close this fd.
+     */
+    len = sizeof(ss);
+    if (getsockname(file, (struct sockaddr*) &ss, &len)) {
+      if (errno == EINVAL)
+        return UV_TCP;
+    }
+#endif
+    return UV_UNKNOWN_HANDLE;
+  }
+
+  if (S_ISREG(s.st_mode))
+    return UV_FILE;
+
+  if (S_ISCHR(s.st_mode))
+    return UV_FILE;  /* XXX UV_NAMED_PIPE? */
+
+  if (S_ISFIFO(s.st_mode))
+    return UV_NAMED_PIPE;
+
+  if (!S_ISSOCK(s.st_mode))
+    return UV_UNKNOWN_HANDLE;
+
+  len = sizeof(ss);
+  if (getsockname(file, (struct sockaddr*) &ss, &len)) {
+#if defined(_AIX)
+    /* On aix receiving RST from TCP instead of FIN immediately puts fd into
+     * an error state. In such case getsockname will return EINVAL, even if
+     * sockaddr_storage is valid.
+     * In such cases, we will permit the user to open the connection as uv_tcp
+     * still, so that the user can get immediately notified of the error in
+     * their read callback and close this fd.
+     */
+    if (errno == EINVAL) {
+      return UV_TCP;
+    }
+#endif
+    return UV_UNKNOWN_HANDLE;
+  }
+
+  len = sizeof(type);
+  if (getsockopt(file, SOL_SOCKET, SO_TYPE, &type, &len))
+    return UV_UNKNOWN_HANDLE;
+
+  if (type == SOCK_DGRAM)
+    if (ss.ss_family == AF_INET || ss.ss_family == AF_INET6)
+      return UV_UDP;
+
+  if (type == SOCK_STREAM) {
+#if defined(_AIX) || defined(__DragonFly__)
+    /* on AIX/DragonFly the getsockname call returns an empty sa structure
+     * for sockets of type AF_UNIX.  For all other types it will
+     * return a properly filled in structure.
+     */
+    if (len == 0)
+      return UV_NAMED_PIPE;
+#endif /* defined(_AIX) || defined(__DragonFly__) */
+
+    if (ss.ss_family == AF_INET || ss.ss_family == AF_INET6)
+      return UV_TCP;
+    if (ss.ss_family == AF_UNIX)
+      return UV_NAMED_PIPE;
+  }
+
+  return UV_UNKNOWN_HANDLE;
+}
+
+
+/* This function is async signal-safe, meaning that it's safe to call from
+ * inside a signal handler _unless_ execution was inside uv_tty_set_mode()'s
+ * critical section when the signal was raised.
+ */
+int uv_tty_reset_mode(void) {
+  int saved_errno;
+  int err;
+
+  saved_errno = errno;
+
+  if (atomic_exchange(&termios_spinlock, 1))
+    return UV_EBUSY;  /* In uv_tty_set_mode() or uv__tty_close(). */
+
+  err = 0;
+  if (orig_termios_fd != -1)
+    err = uv__tcsetattr(orig_termios_fd, TCSANOW, &orig_termios);
+
+  atomic_store(&termios_spinlock, 0);
+  errno = saved_errno;
+
+  return err;
+}
+
+void uv_tty_set_vterm_state(uv_tty_vtermstate_t state) {
+}
+
+int uv_tty_get_vterm_state(uv_tty_vtermstate_t* state) {
+  return UV_ENOTSUP;
+}