Merge `unused_tuple_struct_fields` into `dead_code` #118297

shepmaster · 2023-11-25T20:17:34Z

This implicitly upgrades the lint from allow to warn and places it into the unused lint group.

Discussion on Zulip

rustbot · 2023-11-25T21:38:49Z

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred in src/librustdoc/clean/types.rs

cc @camelid

compiler-errors · 2023-11-25T22:08:24Z

I'd happily take a PR that proactively fixes all of the compiler warnings. Most of them can just be removed, except for the TyCtxt one, which can be replaced with PhantomData.

shepmaster · 2023-11-25T22:22:59Z

Yeah, my plan is to find all of the current issues and submit it as a separate PR, it’s just easier to find it here first.

I was attempting to do that without causing undue noise (thanks rustbot 👀).

compiler/rustc_infer/src/infer/nll_relate/mod.rs

traviscross · 2023-11-26T19:47:32Z

Regarding the T-lang nomination, one of the open questions here is whether this should be part of the dead_code lint now that we're making it warn-by-default.

The motivation for making this part of dead_code is that unused fields of normal structs warn under dead_code, so this would be consistent. E.g.:

warning: field `a` is never read
 --> src/lib.rs:1:12
  |
1 | struct A { a: () }
  |        -   ^
  |        |
  |        field in this struct
  |
  = note: `#[warn(dead_code)]` on by default

On 2022-01-25, T-lang requested this lint be separated from dead_code so that it could be introduced gradually and so people could disable it specifically. The motivation seems to have been the belief that this lint could be "harder to fix than removing named fields, because removing a positional field changes the indices of the following fields".

However, after that decision, on 2022-01-26, @pnkfelix suggested a change to the lint that would allow people to resolve the warning without changing field indices:

...I thought: "well, we should let people include () fields (i.e. not warn about them), and perhaps even have the lint diagnostic here suggest either removing the field or making it have () type. That would keep the indices unchanged."

This change was implemented and is suggested as part of the error message, e.g.:

error: field is never read: `1`
  --> $DIR/tuple-struct-field.rs:6:21
   |
LL | struct Wrapper(i32, [u8; LEN], String);
   |                     ^^^^^^^^^
   |
help: change the field to unit type to suppress this warning while preserving the field numbering
   |
LL | struct Wrapper(i32, (), String);
   |

In discussion in T-compiler in Zulip, the feeling seemed to be that this should be part of dead_code. Given the change suggested by @pnkfelix and implemented in the lint that resolves the issue of preserving field indices, do we now agree?

bors · 2023-11-27T18:09:36Z

☔ The latest upstream changes (presumably #118370) made this pull request unmergeable. Please resolve the merge conflicts.

shepmaster · 2023-11-27T18:48:30Z

a PR that proactively fixes all of the compiler warnings.

Opened in #118382

traviscross · 2023-11-29T17:34:27Z

@rustbot labels -I-lang-nominated

This was discussed in the T-lang triage call today, and the consensus was that it's OK for this to become part of the dead_code lint.

shepmaster · 2023-11-29T18:44:43Z

r? compiler

WaffleLapkin

Just a bit of a nitpick. Feel free to change labels to waiting on review once CI is green

WaffleLapkin · 2023-11-29T21:00:41Z

compiler/rustc_passes/src/dead.rs

+                            if is_pos {
+                                is_positional = true;
+                            }


Isn't this just is_positional = is_pos or is_positional |= is_pos?

Also can't we just do a single check is variant is tuple-like or not, instead of trying to move this out of the loop?..

Isn't this [...] is_positional |= is_pos?

Yeah, I thought about that but wanted to make the diff smaller / easier to see how it changed. Happy to update to this.

do a single check is variant is tuple-like or not

That seems plausible, but I don't know my way around the compiler enough to do so. Got any hints?

instead of trying to move this out of the loop

I thought you were suggesting that we should move it out of the loop — I must not understand what you mean.

I thought you were suggesting that we should move it out of the loop — I must not understand what you mean.

Right, I see why this is confusing.

"trying to move this out of the loop"

this refers to the is_pos which is moved into is_positional, which is outside of the loop.

See rust-lang/rust#118297

See rust-lang/rust#118297.

See rust-lang/rust#118297

…ent, r=Nilstrieb dead_code treats #[repr(transparent)] the same as #[repr(C)] In rust-lang#92972 we enabled linting on unused fields in tuple structs. In rust-lang#118297 that lint was enabled by default. That exposed issues like rust-lang#119659, where the fields of a struct marked `#[repr(transparent)]` were reported by the `dead_code` lint. The language team [decided](rust-lang#119659 (comment)) that the lint should treat `repr(transparent)` the same as `#[repr(C)]`. Fixes rust-lang#119659

Rollup merge of rust-lang#120107 - shepmaster:dead-code-repr-transparent, r=Nilstrieb dead_code treats #[repr(transparent)] the same as #[repr(C)] In rust-lang#92972 we enabled linting on unused fields in tuple structs. In rust-lang#118297 that lint was enabled by default. That exposed issues like rust-lang#119659, where the fields of a struct marked `#[repr(transparent)]` were reported by the `dead_code` lint. The language team [decided](rust-lang#119659 (comment)) that the lint should treat `repr(transparent)` the same as `#[repr(C)]`. Fixes rust-lang#119659

Since rust-lang/rust#118297, Rust treats unused tuple struct fields as dead code. This CL adds an #[allow(dead_code)] to silence the warning. Bug: 318827209 Change-Id: I6858165a085a0ef508722c1ce38f3d95866d2867 Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/972128 Reviewed-by: David Koloski <dkoloski@google.com> Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com> Fuchsia-Auto-Submit: Mitchell Kember <mkember@google.com>

An upcoming rustc change (rust-lang/rust#118297) marks unused tuple fields as dead code. Explicitly mark these structs as allowed to silence the warning/error. Bug: 319472617 Change-Id: I248861cd1343a2906a1e97f7e4af06115913eb88 Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/978876 Reviewed-by: Colin Nelson <colnnelson@google.com> Fuchsia-Auto-Submit: Gwen Mittertreiner <gmtr@google.com> Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>

<rust-lang/rust#118297>

Probably due to rust-lang/rust#118297, our SaslCreds tuple struct now generates a warning. It can be silenced by making the struct public, but it really doesn't need to be, so dead code will be allowd at this point. The warning will presumably end up in stable Rust in a couple of releases.

This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.0 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4 ("rust: upgrade to Rust 1.68.2"). # Unstable features The `offset_of` feature (single-field `offset_of!`) that we were using got stabilized in Rust 1.77.0 [3]. Therefore, now the only unstable features allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [4] for details. # Required changes Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, thus upgrading it from `allow` to `warn` [5]. In turn, this makes `rustc` complain about the `ThisModule`'s pointer field being never read. Thus locally `allow` it for the moment, since we will have users later on (e.g. Binder needs a `as_ptr` method [6]). # Other changes Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there is a Call for Testing going on [8]. We were requested to test it and we found it useful [9] -- we will likely enable it in the future. # `alloc` upgrade and reviewing The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: rust-lang/rust#118799 [3] Link: #2 [4] Link: rust-lang/rust#118297 [5] Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] Link: rust-lang/rfcs#3013 (comment) [8] Link: rust-lang/rust#82450 (comment) [9] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org

This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.0 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4 ("rust: upgrade to Rust 1.68.2"). The `offset_of` feature (single-field `offset_of!`) that we were using got stabilized in Rust 1.77.0 [3]. Therefore, now the only unstable features allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [4] for details. Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, thus upgrading it from `allow` to `warn` [5]. In turn, this makes `rustc` complain about the `ThisModule`'s pointer field being never read. Thus locally `allow` it for the moment, since we will have users later on (e.g. Binder needs a `as_ptr` method [6]). Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there is a Call for Testing going on [8]. We were requested to test it and we found it useful [9] -- we will likely enable it in the future. The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: rust-lang/rust#118799 [3] Link: #2 [4] Link: rust-lang/rust#118297 [5] Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] Link: rust-lang/rfcs#3013 (comment) [8] Link: rust-lang/rust#82450 (comment) [9] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org

Pkgsrc changes: * Adapt checksums and patches. Upstream chnages: Version 1.77.0 (2024-03-21) ========================== - [Reveal opaque types within the defining body for exhaustiveness checking.] (rust-lang/rust#116821) - [Stabilize C-string literals.] (rust-lang/rust#117472) - [Stabilize THIR unsafeck.] (rust-lang/rust#117673) - [Add lint `static_mut_refs` to warn on references to mutable statics.] (rust-lang/rust#117556) - [Support async recursive calls (as long as they have indirection).] (rust-lang/rust#117703) - [Undeprecate lint `unstable_features` and make use of it in the compiler.] (rust-lang/rust#118639) - [Make inductive cycles in coherence ambiguous always.] (rust-lang/rust#118649) - [Get rid of type-driven traversal in const-eval interning] (rust-lang/rust#119044), only as a [future compatiblity lint] (rust-lang/rust#122204) for now. - [Deny braced macro invocations in let-else.] (rust-lang/rust#119062) Compiler -------- - [Include lint `soft_unstable` in future breakage reports.] (rust-lang/rust#116274) - [Make `i128` and `u128` 16-byte aligned on x86-based targets.] (rust-lang/rust#116672) - [Use `--verbose` in diagnostic output.] (rust-lang/rust#119129) - [Improve spacing between printed tokens.] (rust-lang/rust#120227) - [Merge the `unused_tuple_struct_fields` lint into `dead_code`.] (rust-lang/rust#118297) - [Error on incorrect implied bounds in well-formedness check] (rust-lang/rust#118553), with a temporary exception for Bevy. - [Fix coverage instrumentation/reports for non-ASCII source code.] (rust-lang/rust#119033) - [Fix `fn`/`const` items implied bounds and well-formedness check.] (rust-lang/rust#120019) - [Promote `riscv32{im|imafc}-unknown-none-elf` targets to tier 2.] (rust-lang/rust#118704) - Add several new tier 3 targets: - [`aarch64-unknown-illumos`] (rust-lang/rust#112936) - [`hexagon-unknown-none-elf`] (rust-lang/rust#117601) - [`riscv32imafc-esp-espidf`] (rust-lang/rust#119738) - [`riscv32im-risc0-zkvm-elf`] (rust-lang/rust#117958) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Implement `From<&[T; N]>` for `Cow<[T]>`.] (rust-lang/rust#113489) - [Remove special-case handling of `vec.split_off (0)`.](rust-lang/rust#119917) Stabilized APIs --------------- - [`array::each_ref`] (https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_ref) - [`array::each_mut`] (https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_mut) - [`core::net`] (https://doc.rust-lang.org/stable/core/net/index.html) - [`f32::round_ties_even`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.round_ties_even) - [`f64::round_ties_even`] (https://doc.rust-lang.org/stable/std/primitive.f64.html#method.round_ties_even) - [`mem::offset_of!`] (https://doc.rust-lang.org/stable/std/mem/macro.offset_of.html) - [`slice::first_chunk`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.first_chunk) - [`slice::first_chunk_mut`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.first_chunk_mut) - [`slice::split_first_chunk`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_first_chunk) - [`slice::split_first_chunk_mut`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_first_chunk_mut) - [`slice::last_chunk`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.last_chunk) - [`slice::last_chunk_mut`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.last_chunk_mut) - [`slice::split_last_chunk`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_last_chunk) - [`slice::split_last_chunk_mut`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_last_chunk_mut) - [`slice::chunk_by`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.chunk_by) - [`slice::chunk_by_mut`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.chunk_by_mut) - [`Bound::map`] (https://doc.rust-lang.org/stable/std/ops/enum.Bound.html#method.map) - [`File::create_new`] (https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.create_new) - [`Mutex::clear_poison`] (https://doc.rust-lang.org/stable/std/sync/struct.Mutex.html#method.clear_poison) - [`RwLock::clear_poison`] (https://doc.rust-lang.org/stable/std/sync/struct.RwLock.html#method.clear_poison) Cargo ----- - [Extend the build directive syntax with `cargo::`.] (rust-lang/cargo#12201) - [Stabilize metadata `id` format as `PackageIDSpec`.] (rust-lang/cargo#12914) - [Pull out as `cargo-util-schemas` as a crate.] (rust-lang/cargo#13178) - [Strip all debuginfo when debuginfo is not requested.] (rust-lang/cargo#13257) - [Inherit jobserver from env for all kinds of runners.] (rust-lang/cargo#12776) - [Deprecate rustc plugin support in cargo.] (rust-lang/cargo#13248) Rustdoc ----- - [Allows links in markdown headings.] (rust-lang/rust#117662) - [Search for tuples and unit by type with `()`.] (rust-lang/rust#118194) - [Clean up the source sidebar's hide button.] (rust-lang/rust#119066) - [Prevent JS injection from `localStorage`.] (rust-lang/rust#120250) Misc ---- - [Recommend version-sorting for all sorting in style guide.] (rust-lang/rust#115046) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Add more weirdness to `weird-exprs.rs`.] (rust-lang/rust#119028)

This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.0 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4 ("rust: upgrade to Rust 1.68.2"). The `offset_of` feature (single-field `offset_of!`) that we were using got stabilized in Rust 1.77.0 [3]. Therefore, now the only unstable features allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [4] for details. Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, thus upgrading it from `allow` to `warn` [5]. In turn, this makes `rustc` complain about the `ThisModule`'s pointer field being never read. Thus locally `allow` it for the moment, since we will have users later on (e.g. Binder needs a `as_ptr` method [6]). Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there is a Call for Testing going on [8]. We were requested to test it and we found it useful [9] -- we will likely enable it in the future. The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: rust-lang/rust#118799 [3] Link: #2 [4] Link: rust-lang/rust#118297 [5] Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] Link: rust-lang/rfcs#3013 (comment) [8] Link: rust-lang/rust#82450 (comment) [9] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org [boqun: Resolve the conflicts with using upstream alloc]

This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.1 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4 ("rust: upgrade to Rust 1.68.2"). # Unstable features The `offset_of` feature (single-field `offset_of!`) that we were using got stabilized in Rust 1.77.0 [3]. Therefore, now the only unstable features allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [4] for details. # Required changes Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, thus upgrading it from `allow` to `warn` [5]. In turn, this made `rustc` complain about the `ThisModule`'s pointer field being never read, but the previous patch adds the `as_ptr` method to it, needed by Binder [6], so that we do not need to locally `allow` it. # Other changes Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there is a Call for Testing going on [8]. We were requested to test it and we found it useful [9] -- we will likely enable it in the future. # `alloc` upgrade and reviewing The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: rust-lang/rust#118799 [3] Link: Rust-for-Linux#2 [4] Link: rust-lang/rust#118297 [5] Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] Link: rust-lang/rfcs#3013 (comment) [8] Link: rust-lang/rust#82450 (comment) [9] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org [ Upgraded to 1.77.1. No changed to `alloc` during the beta. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.1 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4 ("rust: upgrade to Rust 1.68.2"). # Unstable features The `offset_of` feature (single-field `offset_of!`) that we were using got stabilized in Rust 1.77.0 [3]. Therefore, now the only unstable features allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [4] for details. # Required changes Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, thus upgrading it from `allow` to `warn` [5]. In turn, this made `rustc` complain about the `ThisModule`'s pointer field being never read, but the previous patch adds the `as_ptr` method to it, needed by Binder [6], so that we do not need to locally `allow` it. # Other changes Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there is a Call for Testing going on [8]. We were requested to test it and we found it useful [9] -- we will likely enable it in the future. # `alloc` upgrade and reviewing The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: rust-lang/rust#118799 [3] Link: #2 [4] Link: rust-lang/rust#118297 [5] Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] Link: rust-lang/rfcs#3013 (comment) [8] Link: rust-lang/rust#82450 (comment) [9] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org [ Upgraded to 1.77.1. Removed `allow(dead_code)` thanks to the previous patch. Reworded accordingly. No changes to `alloc` during the beta. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.1 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4 ("rust: upgrade to Rust 1.68.2"). # Unstable features The `offset_of` feature (single-field `offset_of!`) that we were using got stabilized in Rust 1.77.0 [3]. Therefore, now the only unstable features allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [4] for details. # Required changes Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, thus upgrading it from `allow` to `warn` [5]. In turn, this made `rustc` complain about the `ThisModule`'s pointer field being never read, but the previous patch adds the `as_ptr` method to it, needed by Binder [6], so that we do not need to locally `allow` it. # Other changes Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there is a Call for Testing going on [8]. We were requested to test it and we found it useful [9] -- we will likely enable it in the future. # `alloc` upgrade and reviewing The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: rust-lang/rust#118799 [3] Link: Rust-for-Linux#2 [4] Link: rust-lang/rust#118297 [5] Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] Link: rust-lang/rfcs#3013 (comment) [8] Link: rust-lang/rust#82450 (comment) [9] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org [ Upgraded to 1.77.1. Removed `allow(dead_code)` thanks to the previous patch. Reworded accordingly. No changes to `alloc` during the beta. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

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shepmaster force-pushed the warn-dead-tuple-fields branch from 876ee9f to 048aa9d Compare November 25, 2023 20:45

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shepmaster force-pushed the warn-dead-tuple-fields branch from 048aa9d to d254a5f Compare November 25, 2023 21:38

Nadrieril reviewed Nov 25, 2023

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shepmaster mentioned this pull request Nov 26, 2023

Make traits / trait methods detected by the dead code lint #118257

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shepmaster force-pushed the warn-dead-tuple-fields branch from b1f9900 to 0ee2b06 Compare November 29, 2023 18:42

shepmaster changed the title ~~Convert unused_tuple_struct_fields to warn-by-default~~ Merge unused_tuple_struct_fields into dead_code Nov 29, 2023

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tamird mentioned this pull request Jan 6, 2024

dead_code suggestion would break the semantics of code using#[repr(transparent)] #119659

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daxpedda mentioned this pull request Jan 6, 2024

Fix nightly CI rust-windowing/winit#3370

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notgull pushed a commit to rust-windowing/winit that referenced this pull request Jan 6, 2024

ci: Fix dead code error on nightly

f99c810

See rust-lang/rust#118297

tamird added a commit to tamird/git2-rs that referenced this pull request Jan 7, 2024

Appease latest rustc nightly

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See rust-lang/rust#118297.

tamird mentioned this pull request Jan 7, 2024

Appease latest rustc nightly rust-lang/git2-rs#1008

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Mark-Simulacrum added the perf-regression-triaged The performance regression has been triaged. label Jan 8, 2024

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Add name_to_index() & index_to_name() bytecodealliance/rustix#972

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ci: Fix dead code error on nightly

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See rust-lang/rust#118297

kchibisov pushed a commit to rust-windowing/winit that referenced this pull request Jan 15, 2024

ci: Fix dead code error on nightly

c4bfbbe

See rust-lang/rust#118297

dtolnay mentioned this pull request Jan 16, 2024

Remove old unused_tuple_struct_fields lint bitflags/bitflags#393

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shepmaster mentioned this pull request Jan 18, 2024

dead_code treats #[repr(transparent)] the same as #[repr(C)] #120107

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jwodder added a commit to jwodder/rsrepo that referenced this pull request Feb 10, 2024

The unused_tuple_struct_fields lint is going away

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<rust-lang/rust#118297>

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Update rustls version inejge/ldap3#118

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Harden rbx_reflector against unknown data types rojo-rbx/rbx-dom#403

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fix dead_code compile error drahnr/cargo-spellcheck#328

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Merge `unused_tuple_struct_fields` into `dead_code` #118297

Merge `unused_tuple_struct_fields` into `dead_code` #118297

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Merge unused_tuple_struct_fields into dead_code #118297

Merge unused_tuple_struct_fields into dead_code #118297

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Merge `unused_tuple_struct_fields` into `dead_code` #118297

Merge `unused_tuple_struct_fields` into `dead_code` #118297

shepmaster commented Nov 25, 2023 •

edited