-# elif @HAVE_WINSOCK2_H@
-# undef sendto
-# define sendto sendto_used_without_requesting_gnulib_module_sendto
-# elif defined GNULIB_POSIXCHECK
-# undef sendto
-# define sendto(s,b,n,f,a,l) \
- (GL_LINK_WARNING ("sendto is not always POSIX compliant - " \
- "use gnulib module sendto for portability"), \
- sendto (s, b, n, f, a, l))
-# endif
-
-# if @GNULIB_SETSOCKOPT@
-# if @HAVE_WINSOCK2_H@
-# undef setsockopt
-# define setsockopt rpl_setsockopt
-extern int rpl_setsockopt (int, int, int, const void *, socklen_t);
-# endif
-# elif @HAVE_WINSOCK2_H@
-# undef setsockopt
-# define setsockopt setsockopt_used_without_requesting_gnulib_module_setsockopt
-# elif defined GNULIB_POSIXCHECK
-# undef setsockopt
-# define setsockopt(s,lvl,o,v,l) \
- (GL_LINK_WARNING ("setsockopt is not always POSIX compliant - " \
- "use gnulib module setsockopt for portability"), \
- setsockopt (s, lvl, o, v, l))
-# endif
-
-# if @GNULIB_SHUTDOWN@
-# if @HAVE_WINSOCK2_H@
-# undef shutdown
-# define shutdown rpl_shutdown
-extern int rpl_shutdown (int, int);
-# endif
-# elif @HAVE_WINSOCK2_H@
-# undef shutdown
-# define shutdown shutdown_used_without_requesting_gnulib_module_shutdown
-# elif defined GNULIB_POSIXCHECK
-# undef shutdown
-# define shutdown(s,h) \
- (GL_LINK_WARNING ("shutdown is not always POSIX compliant - " \
- "use gnulib module shutdown for portability"), \
- shutdown (s, h))
+_GL_FUNCDECL_RPL (sendto, ssize_t,
+ (int fd, const void *buf, size_t len, int flags,
+ const struct sockaddr *to, socklen_t tolen)
+ _GL_ARG_NONNULL ((2)));
+_GL_CXXALIAS_RPL (sendto, ssize_t,
+ (int fd, const void *buf, size_t len, int flags,
+ const struct sockaddr *to, socklen_t tolen));
+# else
+/* Need to cast, because on NonStop Kernel, the sixth parameter is
+ size_t tolen. */
+_GL_CXXALIAS_SYS_CAST (sendto, ssize_t,
+ (int fd, const void *buf, size_t len, int flags,
+ const struct sockaddr *to, socklen_t tolen));
+# endif
+_GL_CXXALIASWARN (sendto);
+#elif @HAVE_WINSOCK2_H@
+# undef sendto
+# define sendto sendto_used_without_requesting_gnulib_module_sendto
+#elif defined GNULIB_POSIXCHECK
+# undef sendto
+# if HAVE_RAW_DECL_SENDTO
+_GL_WARN_ON_USE (sendto, "sendto is not always POSIX compliant - "
+ "use gnulib module sendto for portability");