On Wed Mar 12, 2025 at 11:24 PM CET, Tamir Duberstein wrote: > On Wed, Mar 12, 2025 at 5:30 PM Benno Lossin <benno.lossin@xxxxxxxxx> wrote: >> >> On Wed Mar 12, 2025 at 10:10 PM CET, Tamir Duberstein wrote: >> > On Wed, Mar 12, 2025 at 5:04 PM Tamir Duberstein <tamird@xxxxxxxxx> wrote: >> >> >> >> On Wed, Mar 12, 2025 at 5:01 PM Benno Lossin <benno.lossin@xxxxxxxxx> wrote: >> >> > Always enable the features, we have `allow(stable_features)` for this >> >> > reason (then you don't have to do this dance with checking if it's >> >> > already stable or not :) >> >> >> >> It's not so simple. In rustc < 1.84.0 the lints *and* the strict >> >> provenance APIs are behind `feature(strict_provenance)`. In rustc >= >> >> 1.84.0 the lints are behind `feature(strict_provenance_lints)`. So you >> >> need to read the config to learn that you need to enable >> >> `feature(strict_provenance_lints)`. >> >> I see... And `strict_provenance_lints` doesn't exist in <1.84? That's a >> bit of a bummer... >> >> But I guess we could have this config option (in `init/Kconfig`): >> >> config RUSTC_HAS_STRICT_PROVENANCE >> def_bool RUSTC_VERSION >= 108400 >> >> and then do this in `lib.rs`: >> >> #![cfg_attr(CONFIG_RUSTC_HAS_STRICT_PROVENANCE, feature(strict_provenance_lints))] > > Yep! That's exactly what I did, but as I mentioned up-thread, the > result is that we only cover the `kernel` crate. Ah I see, can't we just have the above line in the other crate roots? >> > Actually this isn't even the only problem. It seems that >> > `-Astable_features` doesn't affect features enabled on the command >> > line at all: >> > >> > error[E0725]: the feature `strict_provenance` is not in the list of >> > allowed features >> > --> <crate attribute>:1:9 >> > | >> > 1 | feature(strict_provenance) >> > | ^^^^^^^^^^^^^^^^^ >> >> That's because you need to append the feature to `rust_allowed_features` >> in `scripts/Makefile.build` (AFAIK). > > Thanks, that's a helpful pointer, and it solves some problems but not > all. The root Makefile contains this bit: > >> KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \ >> -Zallow-features= $(HOSTRUSTFLAGS) > > which means we can't use the provenance lints against these host > targets (including e.g. `rustdoc_test_gen`). We can't remove this > -Zallow-features= either because then core fails to compile. > > I'm at the point where I think I need more involved help. Want to take > a look at my attempt? It's here: > https://github.com/tamird/linux/tree/b4/ptr-as-ptr. I'll take a look tomorrow, you're testing my knowledge of the build system a lot here :) --- Cheers, Benno
