+#if @GNULIB_UNLOCKPT@
+/* Unlock the slave side of the pseudo-terminal whose master side is specified
+ by FD, so that it can be opened. */
+# if !@HAVE_UNLOCKPT@
+_GL_FUNCDECL_SYS (unlockpt, int, (int fd));
+# endif
+_GL_CXXALIAS_SYS (unlockpt, int, (int fd));
+_GL_CXXALIASWARN (unlockpt);
+#elif defined GNULIB_POSIXCHECK
+# undef unlockpt
+# if HAVE_RAW_DECL_UNLOCKPT
+_GL_WARN_ON_USE (ptsname, "unlockpt is not portable - "
+ "use gnulib module unlockpt for portability");
+# endif
+#endif
+