1 files changed, 40 insertions, 15 deletions

diff --git a/gl/m4/socklen.m4 b/gl/m4/socklen.m4
index 2933d4b..e3efd6e 100644
--- a/gl/m4/socklen.m4
+++ b/gl/m4/socklen.m4
@@ -1,5 +1,5 @@
-# socklen.m4 serial 7
-dnl Copyright (C) 2005, 2006, 2007, 2009, 2010 Free Software Foundation, Inc.
+# socklen.m4 serial 10
+dnl Copyright (C) 2005-2007, 2009-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -8,15 +8,12 @@ dnl From Albert Chin, Windows fixes from Simon Josefsson.
 
 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.  So we
-dnl have to test to find something that will work.
+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.
 
-dnl On mingw32, socklen_t is in ws2tcpip.h ('int'), so we try to find
-dnl it there first.  That file is included by gnulib's sys_socket.in.h, which
-dnl all users of this module should include.  Cygwin must not include
-dnl ws2tcpip.h.
 AC_DEFUN([gl_TYPE_SOCKLEN_T],
-  [AC_REQUIRE([gl_HEADER_SYS_SOCKET])dnl
+  [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],
@@ -44,9 +41,37 @@ AC_DEFUN([gl_TYPE_SOCKLEN_T],
       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])],
-     [#include <sys/types.h>
-      #if HAVE_SYS_SOCKET_H
-      # include <sys/socket.h>
-      #elif HAVE_WS2TCPIP_H
-      # include <ws2tcpip.h>
-      #endif])])
+     [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],
+[
+/* <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>
+#if HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#elif HAVE_WS2TCPIP_H
+# include <ws2tcpip.h>
+#endif
+])
+
+dnl Tests for the existence of the header for socket facilities.
+dnl Defines the C macros HAVE_SYS_SOCKET_H, HAVE_WS2TCPIP_H.
+dnl This macro must match gl_SOCKET_HEADERS.
+AC_DEFUN([gl_CHECK_SOCKET_HEADERS],
+  [AC_CHECK_HEADERS_ONCE([sys/socket.h])
+   if test $ac_cv_header_sys_socket_h = no; then
+     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])
+   fi
+  ])