1# socklen.m4 serial 11
2dnl Copyright (C) 2005-2007, 2009-2020 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7dnl From Albert Chin, Windows fixes from Simon Josefsson.
8
9dnl Check for socklen_t: historically on BSD it is an int, and in
10dnl POSIX 1g it is a type of its own, but some platforms use different
11dnl types for the argument to getsockopt, getpeername, etc.:
12dnl HP-UX 10.20, IRIX 6.5, OSF/1 4.0, Interix 3.5, BeOS.
13dnl So we have to test to find something that will work.
14
15AC_DEFUN([gl_TYPE_SOCKLEN_T],
16  [AC_REQUIRE([gl_CHECK_SOCKET_HEADERS])dnl
17   AC_CHECK_TYPE([socklen_t], ,
18     [AC_CACHE_CHECK([for socklen_t equivalent],
19        [gl_cv_socklen_t_equiv],
20        [# Systems have either "struct sockaddr *" or
21         # "void *" as the second argument to getpeername
22         gl_cv_socklen_t_equiv=
23         for arg2 in "struct sockaddr" void; do
24           for t in int size_t "unsigned int" "long int" "unsigned long int"; do
25             AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
26                 [[#include <sys/types.h>
27                   #include <sys/socket.h>
28
29                   int getpeername (int, $arg2 *, $t *);]],
30                 [[$t len;
31                  getpeername (0, 0, &len);]])],
32               [gl_cv_socklen_t_equiv="$t"])
33             test "$gl_cv_socklen_t_equiv" != "" && break
34           done
35           test "$gl_cv_socklen_t_equiv" != "" && break
36         done
37         if test "$gl_cv_socklen_t_equiv" = ""; then
38           AC_MSG_ERROR([Cannot find a type to use in place of socklen_t])
39         fi
40        ])
41      AC_DEFINE_UNQUOTED([socklen_t], [$gl_cv_socklen_t_equiv],
42        [type to use in place of socklen_t if not defined])],
43     [gl_SOCKET_HEADERS])])
44
45dnl On mingw32, socklen_t is in ws2tcpip.h ('int'), so we try to find
46dnl it there too.  But on Cygwin, wc2tcpip.h must not be included.  Users
47dnl of this module should use the same include pattern as gl_SOCKET_HEADERS.
48dnl When you change this macro, keep also in sync:
49dnl   - gl_CHECK_SOCKET_HEADERS,
50dnl   - the Include section of modules/socklen.
51AC_DEFUN([gl_SOCKET_HEADERS],
52[
53/* <sys/types.h> is not needed according to POSIX, but the
54   <sys/socket.h> in i386-unknown-freebsd4.10 and
55   powerpc-apple-darwin5.5 required it. */
56#include <sys/types.h>
57#if HAVE_SYS_SOCKET_H
58# include <sys/socket.h>
59#elif HAVE_WS2TCPIP_H
60# include <ws2tcpip.h>
61#endif
62])
63
64dnl Tests for the existence of the header for socket facilities.
65dnl Defines the C macros HAVE_SYS_SOCKET_H, HAVE_WS2TCPIP_H.
66dnl This macro must match gl_SOCKET_HEADERS.
67AC_DEFUN([gl_CHECK_SOCKET_HEADERS],
68  [AC_CHECK_HEADERS_ONCE([sys/socket.h])
69   if test $ac_cv_header_sys_socket_h = no; then
70     dnl We cannot use AC_CHECK_HEADERS_ONCE here, because that would make
71     dnl the check for those headers unconditional; yet cygwin reports
72     dnl that the headers are present but cannot be compiled (since on
73     dnl cygwin, all socket information should come from sys/socket.h).
74     AC_CHECK_HEADERS([ws2tcpip.h])
75   fi
76  ])
77