lib/attr.h: use C23 attributes only with gcc >= 10

[kanavin]

These are not available on earlier versions and builds break there.

[alejandro-colomar]

These are not available on earlier versions and builds break there.

Hmmm, I was wondering why no-one had complained about them. I hoped that all users would have a recent enough GCC. Where are you building shadow that triggers this?

I'm fine with the change, I'm just curious. :)

Thanks for the patch!

[alejandro-colomar]

Reviewed-by: Alejandro Colomar <alx@kernel.org>

[kanavin]

Hmmm, I was wondering why no-one had complained about them. I hoped that all users would have a recent enough GCC. Where are you building shadow that triggers this?

Ubuntu 20.04 which has gcc 9.

[alejandro-colomar]

BTW, is this a regression compared to 4.16? Or did 4.16 also not build there?

I guess we should release 4.17.2. Since the master branch is still in a good state, I'll let @hallyn release that one.

I'll merge this patch now. Thanks!

[kanavin]

BTW, is this a regression compared to 4.16? Or did 4.16 also not build there?

4.16 was fine. I think the problem appeared here:
060b084

[alejandro-colomar]

BTW, is this a regression compared to 4.16? Or did 4.16 also not build there?

4.16 was fine. I think the problem appeared here: 060b084

Ahh, yep, the others were covered in version checks already. Thanks!