+
+static int
+rpl_fcntl_DUPFD (int fd, int target)
+{
+ int result;
+#if !HAVE_FCNTL
+ result = dupfd (fd, target, 0);
+#elif FCNTL_DUPFD_BUGGY || REPLACE_FCHDIR
+ /* Detect invalid target; needed for cygwin 1.5.x. */
+ if (target < 0 || getdtablesize () <= target)
+ {
+ result = -1;
+ errno = EINVAL;
+ }
+ else
+ {
+ /* Haiku alpha 2 loses fd flags on original. */
+ int flags = fcntl (fd, F_GETFD);
+ if (flags < 0)
+ result = -1;
+ else
+ {
+ result = fcntl (fd, F_DUPFD, target);
+ if (0 <= result && fcntl (fd, F_SETFD, flags) == -1)
+ {
+ int saved_errno = errno;
+ close (result);
+ result = -1;
+ errno = saved_errno;
+ }
+# if REPLACE_FCHDIR
+ if (0 <= result)
+ result = _gl_register_dup (fd, result);
+# endif
+ }
+ }
+#else
+ result = fcntl (fd, F_DUPFD, target);
+#endif
+ return result;
+}
+
+static int
+rpl_fcntl_DUPFD_CLOEXEC (int fd, int target)
+{
+ int result;
+#if !HAVE_FCNTL
+ result = dupfd (fd, target, O_CLOEXEC);
+#else /* HAVE_FCNTL */
+# if defined __HAIKU__
+ /* On Haiku, the system fcntl (fd, F_DUPFD_CLOEXEC, target) sets
+ the FD_CLOEXEC flag on fd, not on target. Therefore avoid the
+ system fcntl in this case. */
+# define have_dupfd_cloexec -1
+# else
+ /* Try the system call first, if the headers claim it exists
+ (that is, if GNULIB_defined_F_DUPFD_CLOEXEC is 0), since we
+ may be running with a glibc that has the macro but with an
+ older kernel that does not support it. Cache the
+ information on whether the system call really works, but
+ avoid caching failure if the corresponding F_DUPFD fails
+ for any reason. 0 = unknown, 1 = yes, -1 = no. */
+ static int have_dupfd_cloexec = GNULIB_defined_F_DUPFD_CLOEXEC ? -1 : 0;
+ if (0 <= have_dupfd_cloexec)
+ {
+ result = fcntl (fd, F_DUPFD_CLOEXEC, target);
+ if (0 <= result || errno != EINVAL)
+ {
+ have_dupfd_cloexec = 1;
+# if REPLACE_FCHDIR
+ if (0 <= result)
+ result = _gl_register_dup (fd, result);
+# endif
+ }
+ else
+ {
+ result = rpl_fcntl_DUPFD (fd, target);
+ if (result >= 0)
+ have_dupfd_cloexec = -1;
+ }
+ }
+ else
+# endif
+ result = rpl_fcntl_DUPFD (fd, target);
+ if (0 <= result && have_dupfd_cloexec == -1)
+ {
+ int flags = fcntl (result, F_GETFD);
+ if (flags < 0 || fcntl (result, F_SETFD, flags | FD_CLOEXEC) == -1)
+ {
+ int saved_errno = errno;
+ close (result);
+ errno = saved_errno;
+ result = -1;
+ }
+ }
+#endif /* HAVE_FCNTL */
+ return result;
+}
+
+#undef fcntl
+
+#ifdef __KLIBC__
+
+static int
+klibc_fcntl (int fd, int action, /* arg */...);
+{
+ va_list arg_ptr;
+ int arg;
+ struct stat sbuf;
+ int result;
+
+ va_start (arg_ptr, action);
+ arg = va_arg (arg_ptr, int);
+ result = fcntl (fd, action, arg);
+ /* EPERM for F_DUPFD, ENOTSUP for others */
+ if (result == -1 && (errno == EPERM || errno == ENOTSUP)
+ && !fstat (fd, &sbuf) && S_ISDIR (sbuf.st_mode))
+ {
+ ULONG ulMode;
+
+ switch (action)
+ {
+ case F_DUPFD:
+ /* Find available fd */
+ while (fcntl (arg, F_GETFL) != -1 || errno != EBADF)
+ arg++;
+
+ result = dup2 (fd, arg);
+ break;
+
+ /* Using underlying APIs is right ? */
+ case F_GETFD:
+ if (DosQueryFHState (fd, &ulMode))
+ break;
+
+ result = (ulMode & OPEN_FLAGS_NOINHERIT) ? FD_CLOEXEC : 0;
+ break;
+
+ case F_SETFD:
+ if (arg & ~FD_CLOEXEC)
+ break;
+
+ if (DosQueryFHState (fd, &ulMode))
+ break;
+
+ if (arg & FD_CLOEXEC)
+ ulMode |= OPEN_FLAGS_NOINHERIT;
+ else
+ ulMode &= ~OPEN_FLAGS_NOINHERIT;
+
+ /* Filter supported flags. */
+ ulMode &= (OPEN_FLAGS_WRITE_THROUGH | OPEN_FLAGS_FAIL_ON_ERROR
+ | OPEN_FLAGS_NO_CACHE | OPEN_FLAGS_NOINHERIT);
+
+ if (DosSetFHState (fd, ulMode))
+ break;
+
+ result = 0;
+ break;
+
+ case F_GETFL:
+ result = 0;
+ break;
+
+ case F_SETFL:
+ if (arg != 0)
+ break;
+
+ result = 0;
+ break;
+
+ default:
+ errno = EINVAL;
+ break;
+ }
+ }
+
+ va_end (arg_ptr);
+
+ return result;
+}
+
+#endif