On Wed, 20 Aug 2008, Yang Tse wrote:

>> For getting the size to do the checks I mentioned previously in the "Binary
>> compatibility and 64-bit curl_off_t" thread[*], we need to figure out if LFS
>> is explicity disabled on a system that otherwise could support it. I'm not
>> sure how this can be done in any easy manner. The AC_SYS_LARGEFILE macro
>> doesn't seem to disclose this info.
>
> sizeof(off_t) before and after AC_SYS_LARGEFILE perhaps ?

Ah that's a good idea, and then compare it with the size found after the
macro. The only little I experience when trying this out is the fact that
configure caches the result from the check so the second check simply re-uses
the previous result without doing the check again and I haven't yet worked out
how to invalidate that particular cached variable.

> But doing 'configure --disable-largefile' on systems which don't need any
> additional definition to enable LFS won't do anything at all and LFS will
> remain enabled. This is my understanding as of today.

Right, but on these systems I don't see how users would disable LFS easily
when building libcurl either so I'm not terribly worried about them.

-- 
  / daniel.haxx.se