+ # We need to check for ws2tcpip.h now.
+ gl_PREREQ_SYS_H_SOCKET
+ AC_CHECK_TYPES([struct sockaddr_storage, sa_family_t],,,[
+ /* sys/types.h is not needed according to POSIX, but the
+ sys/socket.h in i386-unknown-freebsd4.10 and
+ powerpc-apple-darwin5.5 required it. */
+#include <sys/types.h>
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_WS2TCPIP_H
+#include <ws2tcpip.h>
+#endif
+])
+ if test $ac_cv_type_struct_sockaddr_storage = no; then
+ HAVE_STRUCT_SOCKADDR_STORAGE=0
+ fi
+ if test $ac_cv_type_sa_family_t = no; then
+ HAVE_SA_FAMILY_T=0
+ fi
+ gl_PREREQ_SYS_H_WINSOCK2
+
+ dnl Check for declarations of anything we want to poison if the
+ dnl corresponding gnulib module is not in use.
+ gl_WARN_ON_USE_PREPARE([[
+/* Some systems require prerequisite headers. */
+#include <sys/types.h>
+#if !defined __GLIBC__ && HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include <sys/select.h>
+ ]], [socket connect accept bind getpeername getsockname getsockopt
+ listen recv send recvfrom sendto setsockopt shutdown accept4])
+])
+
+AC_DEFUN([gl_PREREQ_SYS_H_SOCKET],
+[
+ dnl Check prerequisites of the <sys/socket.h> replacement.
+ gl_CHECK_NEXT_HEADERS([sys/socket.h])
+ if test $ac_cv_header_sys_socket_h = yes; then
+ HAVE_SYS_SOCKET_H=1
+ HAVE_WS2TCPIP_H=0
+ else
+ HAVE_SYS_SOCKET_H=0
+ dnl We cannot use AC_CHECK_HEADERS_ONCE here, because that would make
+ dnl the check for those headers unconditional; yet cygwin reports
+ dnl that the headers are present but cannot be compiled (since on
+ dnl cygwin, all socket information should come from sys/socket.h).
+ AC_CHECK_HEADERS([ws2tcpip.h])
+ if test $ac_cv_header_ws2tcpip_h = yes; then
+ HAVE_WS2TCPIP_H=1