Prepare standard library for Rust 2024 migration #136983

ehuss · 2025-02-13T17:40:26Z

This includes a variety of commits preparing the standard library for migration to Rust 2024.

The actual migration is blocked on a few things, so I wanted to get this out of the way in a relatively digestable PR.

rustbot · 2025-02-13T17:40:35Z

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tgross35

The changes here mostly look good to me. However, rand marked Rng::gen deprecated and introduced Rng::random to replace it in version 0.9, released 2 weeks ago. If bumping rand isn't terribly painful (seems pretty compatible), I think it might make sense to do that separately first, which would mean updating the existing uses of gen. Rather than r#gen now and then needing to update again to avoid the deprecation warning.

tgross35 · 2025-02-13T18:02:07Z

library/coretests/tests/pin.rs

-        let _ = unsafe { Pin::new(&mut 2).get_unchecked_mut() };
+        let r = &mut 2;
+        let _ = unsafe { Pin::new(r).get_unchecked_mut() };


Out of curiosity, what makes this necessary?

Tail expression scope changes. In 2024 the temporary &mut 2 would go out of scope at the end of the unsafe block, but get_unchecked_mut is returning a reference tied to it. In 2021, the temporary is extended to the end of the statement.

You know, thinking about this more, I decided it would be a little less weird to write it as:

unsafe { let _ = Pin::new(&mut 2).get_unchecked_mut(); }

rustbot · 2025-02-13T20:25:09Z

The list of allowed third-party dependencies may have been modified! You must ensure that any new dependencies have compatible licenses before merging.

cc @davidtwco, @wesleywiser

These commits modify the library/Cargo.lock file. Unintentional changes to library/Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

ehuss · 2025-02-13T20:25:31Z

If bumping rand isn't terribly painful (seems pretty compatible), I think it might make sense to do that separately first,

Sure, I added a commit that updates rand instead.

ehuss · 2025-02-13T20:57:19Z

I realized I missed a commit for deprecated_safe_2024, so I added it (0f80413).

A small workaround for rust-lang#136899, rustdoc's invalid_rust_codeblocks was not handling this well in 2024. This may be needed when migrating to 2024 when building with stage0.

This generates a warning of irrefutable patterns. I decided to slightly tweak the example so the closure returns unit, since the intent wasn't to show the weird behavior of returning `!`.

tgross35

One question then r=me

tgross35 · 2025-02-13T22:06:01Z

src/tools/tidy/src/deps.rs

@@ -496,6 +500,8 @@ const PERMITTED_STDLIB_DEPENDENCIES: &[&str] = &[
    "windows_x86_64_gnu",
    "windows_x86_64_gnullvm",
    "windows_x86_64_msvc",
+    "zerocopy",
+    "zerocopy-derive",


Where is zerocopy-derive coming from? We have default features off for rand so it shouldn't be through there, I'm not seeing it pop up anywhere in cargo tree for the library.

rand is only a dev dependency so it doesn't really matter, the extra items are just surprising.

I'm guessing it is getting confused by this unusual pinning approach in zerocopy:

[target."cfg(any())".dependencies.zerocopy-derive] version = "=0.8.17"

The dependency list here unconditionally includes all target dependencies.

Huh, that is interesting. The deps appear in library/Cargo.lock though, I guess the pinning causes them to show up there even if they aren't used?

Yea, cargo does the same thing. Cargo.lock is generated as if all the [target] tables are included unconditionally.

I don't think I've ever seen someone use this approach of cfg(any()), it's quite interesting.

Mark-Simulacrum · 2025-02-13T23:15:26Z

Can we hold off on the rand update? See discussion in #136395 around the binaries that adds to the compiler deps (if only actually linked in on wasm)

ehuss · 2025-02-13T23:58:00Z

See discussion in #136395 around the binaries that adds to the compiler deps (if only actually linked in on wasm)

This PR shouldn't bring in wit-bindgen, as this uses default-features=false, none of the wasi stuff is being brought in.

Mark-Simulacrum · 2025-02-14T02:54:43Z

Sounds good, not a concern then. Thanks!

ehuss · 2025-02-14T15:39:53Z

@bors r=tgross35 rollup

bors · 2025-02-14T15:39:58Z

📌 Commit ef20a1b has been approved by tgross35

It is now in the queue for this repository.

Prepare standard library for Rust 2024 migration This includes a variety of commits preparing the standard library for migration to Rust 2024. The actual migration is blocked on a few things, so I wanted to get this out of the way in a relatively digestable PR.

Rollup of 11 pull requests Successful merges: - rust-lang#133312 (triagebot: automatically add more rustdoc related labels) - rust-lang#134016 (Stabilize `const_is_char_boundary` and `const_str_split_at`.) - rust-lang#135813 (CI: split i686-mingw job to three free runners) - rust-lang#136879 (Add safe new() to NotAllOnes) - rust-lang#136971 (Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait`) - rust-lang#136983 (Prepare standard library for Rust 2024 migration) - rust-lang#137002 (Fix early lint check desc in query) - rust-lang#137006 (borrowck diagnostics cleanup: remove an unused and a barely-used field) - rust-lang#137026 (Stabilize (and const-stabilize) `integer_sign_cast`) - rust-lang#137028 (mir_build: Clarify some code for lowering `hir::PatExpr` to THIR) - rust-lang#137032 (Decode metadata buffer in one go) r? `@ghost` `@rustbot` modify labels: rollup

…kingjubilee Rollup of 10 pull requests Successful merges: - rust-lang#133312 (triagebot: automatically add more rustdoc related labels) - rust-lang#134016 (Stabilize `const_is_char_boundary` and `const_str_split_at`.) - rust-lang#136971 (Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait`) - rust-lang#136983 (Prepare standard library for Rust 2024 migration) - rust-lang#137002 (Fix early lint check desc in query) - rust-lang#137006 (borrowck diagnostics cleanup: remove an unused and a barely-used field) - rust-lang#137032 (Decode metadata buffer in one go) - rust-lang#137035 (Normalize closure instance before eagerly monomorphizing it) - rust-lang#137037 (add x86-sse2 (32bit) ABI that requires SSE2 target feature) - rust-lang#137038 (llvm: Tolerate captures in tests) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of rust-lang#136983 - ehuss:misc-2024-prep, r=tgross35 Prepare standard library for Rust 2024 migration This includes a variety of commits preparing the standard library for migration to Rust 2024. The actual migration is blocked on a few things, so I wanted to get this out of the way in a relatively digestable PR.

core: Apply unsafe_attr_outside_unsafe

ef34064

rustbot assigned tgross35 Feb 13, 2025

tgross35 reviewed Feb 13, 2025

View reviewed changes

library: Update rand to 0.9.0

b7c975b

ehuss force-pushed the misc-2024-prep branch from bcdcf7a to 3c25135 Compare February 13, 2025 20:25

rustbot added A-tidy Area: The tidy tool T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap) labels Feb 13, 2025

rustbot added the O-windows Operating system: Windows label Feb 13, 2025

ehuss added 11 commits February 13, 2025 13:10

Migrate coretests to Rust 2024

0aa634e

alloc: Workaround hidden doctest line

890530e

A small workaround for rust-lang#136899, rustdoc's invalid_rust_codeblocks was not handling this well in 2024. This may be needed when migrating to 2024 when building with stage0.

alloc: Apply unsafe_attr_outside_unsafe

55ef73c

alloc: Apply missing_unsafe_on_extern

07ebbdd

std: Apply unsafe_attr_outside_unsafe

9e60b0e

std: Apply missing_unsafe_on_extern

c1791a1

std: Apply dependency_on_unit_never_type_fallback

7dc9e05

This generates a warning of irrefutable patterns. I decided to slightly tweak the example so the closure returns unit, since the intent wasn't to show the weird behavior of returning `!`.

std: Apply rust_2024_incompatible_pat

1ba59f8

std: Apply fixes for tail drop expressions

1b3940f

test: Apply deprecated_safe_2024

36733f3

std: Apply deprecated_safe_2024

ef20a1b

ehuss force-pushed the misc-2024-prep branch from 0f80413 to ef20a1b Compare February 13, 2025 21:10

tgross35 approved these changes Feb 13, 2025

View reviewed changes

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 14, 2025

jhpratt mentioned this pull request Feb 14, 2025

Rollup of 11 pull requests #137040

Closed

workingjubilee mentioned this pull request Feb 14, 2025

Rollup of 10 pull requests #137046

Merged

bors merged commit 922119b into rust-lang:master Feb 15, 2025
6 checks passed

rustbot added this to the 1.86.0 milestone Feb 15, 2025

riking mentioned this pull request Feb 27, 2025

Update to rand 0.9.0 #136395

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Prepare standard library for Rust 2024 migration #136983

Prepare standard library for Rust 2024 migration #136983

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Prepare standard library for Rust 2024 migration #136983

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