AM_CONDITIONAL(PLATFORM_LINUX, echo x$target_os | grep -q linux)
AM_CONDITIONAL(PLATFORM_DARWIN, test x$platform_darwin = xyes)
AM_CONDITIONAL(PLATFORM_SIGPOSIX, test x$use_sigposix = xyes)
AM_CONDITIONAL(PLATFORM_LINUX, echo x$target_os | grep -q linux)
AM_CONDITIONAL(PLATFORM_DARWIN, test x$platform_darwin = xyes)
AM_CONDITIONAL(PLATFORM_SIGPOSIX, test x$use_sigposix = xyes)