On Wed, Mar 12, 2025 at 5:30 PM Benno Lossin benno.lossin@proton.me 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@gmail.com wrote:
On Wed, Mar 12, 2025 at 5:01 PM Benno Lossin benno.lossin@proton.me 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 >= 108400and 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.
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.
Thanks! Tamir