# | |
# When allocating RWX memory, check whether we need to use /dev/zero | |
# as the file descriptor or not. | |
# | |
AC_DEFUN([AC_NEED_DEV_ZERO_FOR_MMAP], | |
[AC_CACHE_CHECK([if /dev/zero is needed for mmap], | |
ac_cv_need_dev_zero_for_mmap, | |
[if test "$llvm_cv_os_type" = "Interix" ; then | |
ac_cv_need_dev_zero_for_mmap=yes | |
else | |
ac_cv_need_dev_zero_for_mmap=no | |
fi | |
]) | |
if test "$ac_cv_need_dev_zero_for_mmap" = yes; then | |
AC_DEFINE([NEED_DEV_ZERO_FOR_MMAP],[1], | |
[Define if /dev/zero should be used when mapping RWX memory, or undefine if its not necessary]) | |
fi]) |