fork

REMOTE_LIBS=
if test "$enable_backend_remote" = yes ; then
  AC_PREPROC_IFELSE([AC_LANG_SOURCE([[
#ifdef __WIN32__
#error WIN32
#endif
  ]])], [win32=no], [win32=yes])

  case $host_os-$win32 in
    *-yes )
      dnl For mingw and msvc we have an alternative implementation which
      dnl doesn't need fork() or socketpair().
      dnl
      dnl We need -lws2_32 for getaddrinfo(), etc.
      REMOTE_LIBS=-lws2_32
      dnl Vista is needed for the AI_ADDRCONFIG flag to getaddrinfo().
      AC_DEFINE([WINVER], [0x600],
        [Version of Windows to assume (0x600 => Vista).])
      AC_DEFINE([_WIN32_WINNT], [WINVER],
        [Version of Windows to assume.])
      ;;
    *djgpp* | *msdos* )
      dnl DJGPP has a dummy implementation of fork which always fails.
      dnl
      dnl For disk-based backend, use flock() for locking, which doesn't need
      dnl fork() or socketpair().
      AC_DEFINE([FLINTLOCK_USE_FLOCK], 1, [Define to use flock() for flint-compatible locking])
      dnl If someone actually wanted remote backend support, then DJGPP has a
      dnl pthreads port, so using threads like we do on Windows would make more
      dnl sense.
      enable_backend_remote=no
      ;;
    *)
      dnl On Unix, we need fork and socketpair for the remotebackend.
      SAVE_LIBS=$LIBS
      AC_CHECK_FUNCS([fork], [], [
    AC_MSG_ERROR([fork() required for the remote backend - if an extra library is needed, pass LIBS=-lfoo to configure.  Or --disable-backend-remote to disable it.)])
      ])
      dnl Check if -lsocket is required for socketpair (Solaris needs it).
      dnl And on Haiku it's in -lnetwork.
      AC_SEARCH_LIBS([socketpair], [socket network], [], [
    AC_MSG_ERROR([socketpair() required for the remote backend - if an extra library is needed, pass LIBS=-lfoo to configure.  Or --disable-backend-remote to disable it.)])
      ])
      AC_DEFINE([HAVE_SOCKETPAIR], [1],
        [Define to 1 if you have the 'socketpair' function.])
      dnl Check if extra libraries are needed for getaddrinfo or inet_ntop()
      dnl (e.g. on Solaris).
      dnl
      dnl We're currently assuming that any system that is worth trying to
      dnl support has getaddrinfo() and inet_ntop(), since these are the
      dnl standard route for supporting IPv6, and that's pretty much essential
      dnl for platforms to support now.
      AC_SEARCH_LIBS([getaddrinfo], [nsl socket], [], [
    AC_MSG_ERROR([getaddrinfo() required for the remote backend - if an extra library is needed, pass LIBS=-lfoo to configure.  Or --disable-backend-remote to disable it.)])
      ])
      AC_SEARCH_LIBS([inet_ntop], [nsl socket], [], [
    AC_MSG_ERROR([inet_ntop() required for the remote backend - if an extra library is needed, pass LIBS=-lfoo to configure.  Or --disable-backend-remote to disable it.)])
      ])
      REMOTE_LIBS=$LIBS
      LIBS=$SAVE_LIBS
      ;;
  esac

  if test "$enable_backend_remote" = yes ; then
    TYPE_SOCKLEN_T
    XAPIAN_LIBS="$XAPIAN_LIBS $REMOTE_LIBS"
  fi
fi