+dnl Check for socklen_t: historically on BSD it is an int, and in
+dnl POSIX 1g it is a type of its own, but some platforms use different
+dnl types for the argument to getsockopt, getpeername, etc.:
+dnl HP-UX 10.20, IRIX 6.5, OSF/1 4.0, Interix 3.5, BeOS.
+dnl So we have to test to find something that will work.
+
+AC_DEFUN([gl_TYPE_SOCKLEN_T],
+ [AC_REQUIRE([gl_CHECK_SOCKET_HEADERS])dnl
+ AC_CHECK_TYPE([socklen_t], ,
+ [AC_MSG_CHECKING([for socklen_t equivalent])
+ AC_CACHE_VAL([gl_cv_socklen_t_equiv],
+ [# Systems have either "struct sockaddr *" or
+ # "void *" as the second argument to getpeername
+ gl_cv_socklen_t_equiv=
+ for arg2 in "struct sockaddr" void; do
+ for t in int size_t "unsigned int" "long int" "unsigned long int"; do
+ AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+ [[#include <sys/types.h>
+ #include <sys/socket.h>
+
+ int getpeername (int, $arg2 *, $t *);]],
+ [[$t len;
+ getpeername (0, 0, &len);]])],
+ [gl_cv_socklen_t_equiv="$t"])
+ test "$gl_cv_socklen_t_equiv" != "" && break
+ done
+ test "$gl_cv_socklen_t_equiv" != "" && break
+ done
+ ])
+ if test "$gl_cv_socklen_t_equiv" = ""; then
+ AC_MSG_ERROR([Cannot find a type to use in place of socklen_t])
+ fi
+ AC_MSG_RESULT([$gl_cv_socklen_t_equiv])
+ AC_DEFINE_UNQUOTED([socklen_t], [$gl_cv_socklen_t_equiv],
+ [type to use in place of socklen_t if not defined])],
+ [gl_SOCKET_HEADERS])])
+
+dnl On mingw32, socklen_t is in ws2tcpip.h ('int'), so we try to find
+dnl it there too. But on Cygwin, wc2tcpip.h must not be included. Users
+dnl of this module should use the same include pattern as gl_SOCKET_HEADERS.
+dnl When you change this macro, keep also in sync:
+dnl - gl_CHECK_SOCKET_HEADERS,
+dnl - the Include section of modules/socklen.
+AC_DEFUN([gl_SOCKET_HEADERS],