On Wed, Mar 12, 2025 at 5:01 PM Benno Lossin <benno.lossin@xxxxxxxxx> wrote: > > On Wed Mar 12, 2025 at 9:41 PM CET, Tamir Duberstein wrote: > > On Wed, Mar 12, 2025 at 4:07 PM Tamir Duberstein <tamird@xxxxxxxxx> wrote: > >> > >> On Wed, Mar 12, 2025 at 3:43 PM Benno Lossin <benno.lossin@xxxxxxxxx> wrote: > >> > > >> > On Wed Mar 12, 2025 at 8:19 PM CET, Tamir Duberstein wrote: > >> > > I tried using the strict provenance lints locally and I think we can't > >> > > until we properly bump MSRV due to `clippy::incompatible_msrv`: > >> > > > >> > > warning: current MSRV (Minimum Supported Rust Version) is `1.78.0` but > >> > > this item is stable since `1.84.0` > >> > > --> ../rust/kernel/str.rs:696:22 > >> > > | > >> > > 696 | pos: pos.expose_provenance(), > >> > > | ^^^^^^^^^^^^^^^^^^^ > >> > > | > >> > > = help: for further information visit > >> > > https://rust-lang.github.io/rust-clippy/master/index.html#incompatible_msrv > >> > > >> > Oh this is annoying... > >> > > >> > > This is with `#![feature(strict_provenance)]`. I can file the issue > >> > > but I think it's blocked on MSRV >= 1.84.0. But maybe you know of a > >> > > path forward :) > >> > > >> > I think we should be able to just `allow(clippy::incompatible_msrv)`, > >> > since Miguel & other maintainers will test with 1.78 (or at least are > >> > supposed to :). > >> > >> Alright, you've sniped me. This is coming in v3. > > > > I just realized I only covered the kernel crate. In order to cover all > > Rust code, I need to move the lints and the features out to the root > > Makefile. I tried something like this: > > > >> diff --git a/Makefile b/Makefile > >> index 2af40bfed9ce..10af1e44370b 100644 > >> --- a/Makefile > >> +++ b/Makefile > >> @@ -466,13 +466,21 @@ KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ > >> KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS) > >> KBUILD_USERLDFLAGS := $(USERLDFLAGS) > >> > >> +# Lints were moved to `strict_provenance_lints` when `strict_provenance` was stabilized. > >> +# > >> +# See https://github.com/rust-lang/rust/commit/56ee492a6e7a917b2b3f888e33dd52a13d3ecb64. > >> +KBUILD_RUST_STRICT_PROVENANCE_FEATURE = $(if $(CONFIG_RUSTC_HAS_STABLE_STRICT_PROVENANCE),strict_provenance_lints,strict_provenance) > >> + > >> # These flags apply to all Rust code in the tree, including the kernel and > >> # host programs. > >> export rust_common_flags := --edition=2021 \ > >> -Zbinary_dep_depinfo=y \ > >> + -Zcrate-attr="feature($(KBUILD_RUST_STRICT_PROVENANCE_FEATURE))" \ > >> -Astable_features \ > >> -Dnon_ascii_idents \ > >> -Dunsafe_op_in_unsafe_fn \ > >> + -Wfuzzy_provenance_casts \ > >> + -Wlossy_provenance_casts \ > >> -Wmissing_docs \ > >> -Wrust_2018_idioms \ > >> -Wunreachable_pub \ > >> diff --git a/rust/Makefile b/rust/Makefile > >> index ea3849eb78f6..d7d5be741245 100644 > >> --- a/rust/Makefile > >> +++ b/rust/Makefile > >> @@ -435,8 +435,10 @@ $(obj)/helpers/helpers.o: $(src)/helpers/helpers.c $(recordmcount_source) FORCE > >> # symbol versions generated from Rust objects. > >> $(obj)/exports.o: private skip_gendwarfksyms = 1 > >> > >> +KBUILD_RUST_STRICT_PROVENANCE_FEATURE := $(if $(CONFIG_RUSTC_HAS_STABLE_STRICT_PROVENANCE),strict_provenance_lints,strict_provenance) > >> + > >> $(obj)/core.o: private skip_clippy = 1 > >> -$(obj)/core.o: private skip_flags = -Wunreachable_pub > >> +$(obj)/core.o: private skip_flags = -Zcrate-attr="feature($(KBUILD_RUST_STRICT_PROVENANCE_FEATURE))" -Wunreachable_pub -Wfuzzy_provenance_casts -Wlossy_provenance_casts > >> $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym)) > >> $(obj)/core.o: private rustc_target_flags = $(core-cfgs) > >> $(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs \ > > > > but this doesn't work because > > `CONFIG_RUSTC_HAS_STABLE_STRICT_PROVENANCE` is not yet defined when I > > read it in the root Makefile. I can read it lower down and then append > > the feature flag to `KBUILD_RUSTFLAGS` but by then the rustdoc flags > > have been copied from `rust_common_flags` and so rustdoc doesn't get > > the feature flag, resulting in unknown lint warnings in rustdoc and > > kunit tests. > > > > Any ideas? > > 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)`.
