# Re: \[PATCH net-next v3 1/7\] overflow: add DEFINE\_FLEX() for on-stack allocs

- From: Miguel Ojeda \<hidden\>
- Date: 2023-08-18 11:10:20 
- List: netdev
- Page: https://ratatoskr.run/netdev/2023/08/11269946
- Thread: https://ratatoskr.run/rust-for-linux/2023/08/11269942/t.md

```text
On Fri, Aug 18, 2023 at 12:38 PM Przemek Kitszel
[ref] wrote:
>
> Rust folks, could you please tell me if this is something I should fix,
> or I just uncovered some existing bug in "unstable" thing?
>
> Perhaps it is worth to mention, diff of v3 vs v2 is:
> move dummy implementation of __has_builtin() macro to the top of
> compiler_types.h, just before `#ifndef ASSEMBLY`

Nothing you need to worry about, it is an issue with old `bindgen` and
LLVM >= 16, fixed in commit 08ab786556ff ("rust: bindgen: upgrade to
0.65.1") which is in `rust-next` at the moment. Sorry about that, and
thanks for pinging us!

LKP / Yujie / Philip: since we got a few reports on this, would it be
possible to avoid LLVM >= 16 for Rust-enabled builds for any branch
that does not include the new `bindgen` or at least 08ab786556ff? Or,
if Greg is OK with that, I guess we could also backport the upgrade,
but perhaps it is a bit too much for stable?

Cheers,
Miguel
```