Re: suggested fix

[Steven Chamberlain <steven@pyro.eu.org>]

Hi Nicholas,

On 20/06/12 12:53, Nicholas Bamber wrote:
> Sorry I didn't notice the FTBS on hurd as I was concentrating on the
> red. I guess I should have trusted the bug report title more.

I only noticed on buildd.d.o that the failure was the same there.

> However I am confused at what your are proposing.

If you're not convinced, then the patch you have is fine.  It would fix
the immediate FTBFS on kfreebsd-* and this could be revisited later.

I was only trying to kill two (or more) birds with one stone here, by
accommodating GNU/Hurd, and keeping portability to some other future
k*BSD port, and if the patch is forwarded upstream they might like it to
fix this on other arches they support.

> For a start I cannot
> find a net/if_dl.h file on Hurd.

I'm not sure...  be warned that packages.d.o might not be indexing
package contents for GNU/Hurd.  (At least once before this has caught me
out).

For the Hurd, I thought, if the header inclusion test was AF_LINK:

1. if it supports sockaddr_dl, and has net/if_dl.h, it would be fixed

2. if it supports sockaddr_dl, but currently lacks net/if_dl.h, the new
build error would make the problem clearer, and it could build in future
without changes after they provide the missing net/if_dl.h

3. if it doesn't support sockaddr_dl, the AF_LINK test is wrong in
_both_ places so it wouldn't be able to build anyway;  we'd be no worse-off.

> Secondly I am not clear if using
> AF_LINK as a conditional is a good idea. Surely that would change the
> code on Linux, which is surely not what we want to do.

I was assuming that platforms without sockaddr_dl don't define AF_LINK.
 I don't see it in the Linux headers.

And the FXR pages also showed a correlation between AF_LINK being
defined on a platform, and the existence of a net/if_dl.h containing the
definition of sockaddr_dl.

Regards,
-- 
Steven Chamberlain
steven@pyro.eu.org