bpo-40280: Add configure check for socket shutdown (GH-29795)

Misc/NEWS.d/next/Build/2021-11-26-14-09-04.bpo-40280.ZLpwQf.rst

@@ -0,0 +1,3 @@
+``configure`` now checks for socket ``shutdown`` function. The check makes
+it possible to disable ``SYS_shutdown`` with ``ac_cv_func_shutdown=no`` in
+CONFIG_SITE.

Modules/socketmodule.c

@@ -4788,6 +4788,7 @@ Set operation mode, IV and length of associated data for an AF_ALG\n\
 operation socket.");
 #endif
 
+#ifdef HAVE_SHUTDOWN
 /* s.shutdown(how) method */
 
 static PyObject *
@@ -4812,6 +4813,7 @@ PyDoc_STRVAR(shutdown_doc,
 \n\
 Shut down the reading side of the socket (flag == SHUT_RD), the writing side\n\
 of the socket (flag == SHUT_WR), or both ends (flag == SHUT_RDWR).");
+#endif
 
 #if defined(MS_WINDOWS) && defined(SIO_RCVALL)
 static PyObject*
@@ -4957,8 +4959,10 @@ static PyMethodDef sock_methods[] = {
                       gettimeout_doc},
     {"setsockopt",        (PyCFunction)sock_setsockopt, METH_VARARGS,
                       setsockopt_doc},
+#ifdef HAVE_SHUTDOWN
     {"shutdown",          (PyCFunction)sock_shutdown, METH_O,
                       shutdown_doc},
+#endif
 #ifdef CMSG_LEN
     {"recvmsg",           (PyCFunction)sock_recvmsg, METH_VARARGS,
                       recvmsg_doc},

PC/pyconfig.h

@@ -517,6 +517,9 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
 /* Define if you have siginterrupt.  */
 /* #undef HAVE_SIGINTERRUPT */
 
+/* Define to 1 if you have the `shutdown' function. */
+#define HAVE_SHUTDOWN 1
+
 /* Define if you have symlink.  */
 /* #undef HAVE_SYMLINK */
 

configure

@@ -13395,7 +13395,7 @@ for ac_func in alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
  setgid sethostname \
  setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \
  sched_get_priority_max sched_setaffinity sched_setscheduler sched_setparam \
- sched_rr_get_interval \
+ sched_rr_get_interval shutdown \
  sigaction sigaltstack sigfillset siginterrupt sigpending sigrelse \
  sigtimedwait sigwait sigwaitinfo snprintf splice strftime strlcpy strsignal symlinkat sync \
  sysconf tcgetpgrp tcsetpgrp tempnam timegm times tmpfile tmpnam tmpnam_r \

configure.ac

@@ -3956,7 +3956,7 @@ AC_CHECK_FUNCS(alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
  setgid sethostname \
  setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \
  sched_get_priority_max sched_setaffinity sched_setscheduler sched_setparam \
- sched_rr_get_interval \
+ sched_rr_get_interval shutdown \
  sigaction sigaltstack sigfillset siginterrupt sigpending sigrelse \
  sigtimedwait sigwait sigwaitinfo snprintf splice strftime strlcpy strsignal symlinkat sync \
  sysconf tcgetpgrp tcsetpgrp tempnam timegm times tmpfile tmpnam tmpnam_r \

pyconfig.h.in

@@ -992,6 +992,9 @@
 /* Define to 1 if you have the `shm_unlink' function. */
 #undef HAVE_SHM_UNLINK
 
+/* Define to 1 if you have the `shutdown' function. */
+#undef HAVE_SHUTDOWN
+
 /* Define to 1 if you have the `sigaction' function. */
 #undef HAVE_SIGACTION