Ensure correct syntax when sys/select.h is replaced but sys/socket.h is not.
[gnulib.git] / m4 / sys_select_h.m4
1 # sys_select_h.m4 serial 5
2 dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
6
7 AC_DEFUN([gl_HEADER_SYS_SELECT],
8 [
9   AC_REQUIRE([gl_HEADER_SYS_SOCKET])
10   AC_CACHE_CHECK([whether <sys/select.h> is self-contained],
11     [gl_cv_header_sys_select_h_selfcontained],
12     [
13       AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/select.h>]], [[]])],
14         [gl_cv_header_sys_select_h_selfcontained=yes],
15         [gl_cv_header_sys_select_h_selfcontained=no])
16     ])
17   if test $gl_cv_header_sys_select_h_selfcontained = yes; then
18     SYS_SELECT_H=''
19   else
20     SYS_SELECT_H='sys/select.h'
21     gl_CHECK_NEXT_HEADERS([sys/select.h])
22     if test $ac_cv_header_sys_select_h = yes; then
23       HAVE_SYS_SELECT_H=1
24     else
25       HAVE_SYS_SELECT_H=0
26     fi
27     AC_SUBST([HAVE_SYS_SELECT_H])
28     gl_PREREQ_SYS_H_WINSOCK2
29   fi
30   AC_SUBST([SYS_SELECT_H])
31   if test x$ac_cv_header_winsock2_h = xyes; then
32     AC_LIBOBJ(winsock-select)
33   fi
34 ])