On Mon, Feb 10, 2025 at 05:37:32PM +0100, Miguel Ojeda wrote: > Starting with Rust 1.85.0 (to be released 2025-02-20), `rustc` warns > [1] about disabling neon in the aarch64 hardfloat target: > > warning: target feature `neon` cannot be toggled with > `-Ctarget-feature`: unsound on hard-float targets > because it changes float ABI > | > = note: this was previously accepted by the compiler but > is being phased out; it will become a hard error > in a future release! > = note: for more information, see issue #116344 > <https://github.com/rust-lang/rust/issues/116344> > > Thus, instead, use the softfloat target instead. > > While trying it out, I found that the kernel sanitizers were not enabled > for that built-in target [2]. Upstream Rust agreed to backport > the enablement for the current beta so that it is ready for > the 1.85.0 release [3] -- thanks! > > However, that still means that before Rust 1.85.0, we cannot switch > since sanitizers could be in use. Thus conditionally do so. > > Cc: <stable@xxxxxxxxxxxxxxx> # Needed in 6.12.y and 6.13.y only (Rust is pinned in older LTSs). > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > Cc: Matthew Maurer <mmaurer@xxxxxxxxxx> > Cc: Alice Ryhl <aliceryhl@xxxxxxxxxx> > Cc: Ralf Jung <post@xxxxxxxx> > Cc: Jubilee Young <workingjubilee@xxxxxxxxx> > Link: https://github.com/rust-lang/rust/pull/133417 [1] > Link: https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/arm64.20neon.20.60-Ctarget-feature.60.20warning/near/495358442 [2] > Link: https://github.com/rust-lang/rust/pull/135905 [3] > Link: https://github.com/rust-lang/rust/issues/116344 > Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> > --- > Matthew: if you could please give this a go and confirm that it is fine > for Android (with sanitizers enabled, for 1.84.1 and 1.85.0), then a > Tested-by tag would be great. Thanks! Patch looks fine to me, but I'll wait for Matthew to confirm that it works for them. I'm also fine with adding the rustc-min-version helper at the same time, tbh -- it's not exactly rocket science, but it would need an Ack from Masahiro. Will
