Re: C aggregate passing (Rust kernel policy)

Kent Overstreet
2025-02-22T20:49:40Z

On Sat, Feb 22, 2025 at 08:41:52PM +0100, Miguel Ojeda wrote:
> On Sat, Feb 22, 2025 at 7:54 PM Kent Overstreet
> <kent.overstreet@linux.dev> wrote:
> >
> > I believe (Miguel was talking about this at one of the conferences,
> > maybe he'll chime in) that there was work in progress to solidify the
> > aliasing and ownership rules at the unsafe level, but it sounded like it
> > may have still been an area of research.
>
> Not sure what I said, but Cc'ing Ralf in case he has time and wants to
> share something on this (thanks in advance!).

Yeah, this looks like just the thing. At the conference you were talking
more about memory provenance in C, if memory serves there was cross
pollination going on between the C and Rust folks - did anything come of
the C side?

>
> From a quick look, Tree Borrows was submitted for publication back in November:
>
> https://jhostert.de/assets/pdf/papers/villani2024trees.pdf
> https://perso.crans.org/vanille/treebor/

That's it.

This looks fantastic, much further along than the last time I looked.
The only question I'm trying to answer is whether it's been pushed far
enough into llvm for the optimization opportunities to be realized - I'd
quite like to take a look at some generated code.