m4/poll.m4

   1 # poll.m4 serial 17
   2 dnl Copyright (c) 2003, 2005-2007, 2009-2014 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_FUNC_POLL],
   8 [
   9   AC_REQUIRE([gl_POLL_H])
  10   AC_REQUIRE([gl_SOCKETS])
  11   if test $ac_cv_header_poll_h = no; then
  12     ac_cv_func_poll=no
  13     gl_cv_func_poll=no
  14   else
  15     AC_CHECK_FUNC([poll],
  16       [# Check whether poll() works on special files (like /dev/null) and
  17        # and ttys (like /dev/tty). On Mac OS X 10.4.0 and AIX 5.3, it doesn't.
  18        AC_RUN_IFELSE([AC_LANG_SOURCE([[
  19 #include <fcntl.h>
  20 #include <poll.h>
  21          int main()
  22          {
  23            int result = 0;
  24            struct pollfd ufd;
  25            /* Try /dev/null for reading.  */
  26            ufd.fd = open ("/dev/null", O_RDONLY);
  27            /* If /dev/null does not exist, it's not Mac OS X nor AIX. */
  28            if (ufd.fd >= 0)
  29              {
  30                ufd.events = POLLIN;
  31                ufd.revents = 0;
  32                if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLIN))
  33                  result |= 1;
  34              }
  35            /* Try /dev/null for writing.  */
  36            ufd.fd = open ("/dev/null", O_WRONLY);
  37            /* If /dev/null does not exist, it's not Mac OS X nor AIX. */
  38            if (ufd.fd >= 0)
  39              {
  40                ufd.events = POLLOUT;
  41                ufd.revents = 0;
  42                if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLOUT))
  43                  result |= 2;
  44              }
  45            /* Trying /dev/tty may be too environment dependent.  */
  46            return result;
  47          }]])],
  48          [gl_cv_func_poll=yes],
  49          [gl_cv_func_poll=no],
  50          [# When cross-compiling, assume that poll() works everywhere except on
  51           # Mac OS X or AIX, regardless of its version.
  52           AC_EGREP_CPP([MacOSX], [
  53 #if (defined(__APPLE__) && defined(__MACH__)) || defined(_AIX)
  54 This is MacOSX or AIX
  55 #endif
  56 ], [gl_cv_func_poll=no], [gl_cv_func_poll=yes])])])
  57   fi
  58   if test $gl_cv_func_poll != yes; then
  59     AC_CHECK_FUNC([poll], [ac_cv_func_poll=yes], [ac_cv_func_poll=no])
  60     if test $ac_cv_func_poll = no; then
  61       HAVE_POLL=0
  62     else
  63       REPLACE_POLL=1
  64     fi
  65   fi
  66   if test $HAVE_POLL = 0 || test $REPLACE_POLL = 1; then
  67     :
  68   else
  69     AC_DEFINE([HAVE_POLL], [1],
  70       [Define to 1 if you have the 'poll' function and it works.])
  71   fi
  72
  73   dnl Determine the needed libraries.
  74   LIB_POLL="$LIBSOCKET"
  75   if test $HAVE_POLL = 0 || test $REPLACE_POLL = 1; then
  76     case "$host_os" in
  77       mingw*)
  78         dnl On the MSVC platform, the function MsgWaitForMultipleObjects
  79         dnl (used in lib/poll.c) requires linking with -luser32. On mingw,
  80         dnl it is implicit.
  81         AC_LINK_IFELSE(
  82           [AC_LANG_SOURCE([[
  83 #define WIN32_LEAN_AND_MEAN
  84 #include <windows.h>
  85 int
  86 main ()
  87 {
  88   MsgWaitForMultipleObjects (0, NULL, 0, 0, 0);
  89   return 0;
  90 }]])],
  91           [],
  92           [LIB_POLL="$LIB_POLL -luser32"])
  93         ;;
  94     esac
  95   fi
  96   AC_SUBST([LIB_POLL])
  97 ])
  98
  99 # Prerequisites of lib/poll.c.
 100 AC_DEFUN([gl_PREREQ_POLL],
 101 [
 102   AC_CHECK_HEADERS_ONCE([sys/ioctl.h sys/filio.h])
 103 ])