On Thu, Jan 25, 2024 at 1:31 PM Conor Dooley <conor.dooley@xxxxxxxxxxxxx> wrote: > > I chatted with the clang built linux folks about this yesterday, Nathan > agreed that dealing with incompatibility issues iff they crop up is a > reasonable way to go. > > If by "the bindgen found one matches the C compiler" you mean that the > version of libclang used by bindgen matches the C compiler, then that > sounds great. Yeah, exactly. So, unless I am misunderstanding, the incompatibilities could only happen if someone ignores the warning. We could make it an error too. > > For `bindgen` under GCC builds, we will eventually want a "proper" way > > to use GCC instead (or possibly other approaches like querying the > > information): https://github.com/rust-lang/rust-bindgen/issues/1949. > > > Recently, there has been a thread in our Zulip and a couple people are > > experimenting: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-General/topic/Bindgen.20--.20GCC.20backend.20port > > That link for me goes to a message on 22/01, so later than the email you > sent. Zulip seems to scroll to the latest message in the topic -- you should be able to scroll a bit up, but if that doesn't work, this link should go to the first message: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-General/topic/Bindgen.20--.20GCC.20backend.20port/near/412609074 > That said, I gave things another spin today, in a different environment, > as a final check before sending and found an issue causing kernel > panics. RISC-V (and x86/arm64) supports kcfi (CFI_CLANG) but enabling > sanitisers seems to be a nightly only option for rustc. The kernel I > built today had CFI_CLANG enabled and that caused panics when the rust > samples were loaded. > > The CFI_CLANG Kconfig entry has a cc-option test for whether the option > is supported, but from a quick check I don't see a comparable test to > use for rust. Even if a test was added, the current flag is an unstable > one, so I am not sure if testing for it is the right call in the first > place, given the stabilised flag would be entirely different? Yeah, KCFI and other mitigations is WIP -- Cc'ing Ramon and Matthew who may be able to tell us the latest status. Testing for unstable flags is fine, i.e. we only support a single compiler, so we can change the name when we do the upgrade. Cheers, Miguel
