migrate to 2024 edition

[jonaspleyer]

This is an initial advancement to increase the edition version to 2024. In particular I have done the following non-structural changes:

• Add the unsafe keyword to function calls of unsafe functions
• Mark extern "C" blocks as unsafe extern "C"

For now, the error messages which are being produced are different to the previous ones. I have commented out the test_compile_errors test case. The remaining tests are all passing.
I have not yet added an entry into the newsfragments folder but in the process of merging this PR, I can do this as well.

Let me know what you think.

[alex]

Thanks for working on this.

Since this requires raising our MSRV significantly, this isn't something we'll be able to consider merging in the new future.

It looks like overwhelmingly these changes relate to how unsafe scoping works. I believe there are some warnings we can enable on older versions of Rust to get the same behavior? If so, it probably makes sense to see if those can be landed now, independent of raising the edition.

[codspeed-hq]

CodSpeed Performance Report

Merging #4976 will not alter performance

_{Comparing jonaspleyer:main (7f601f0) with main (f08cc60)}

Summary

✅ 87 untouched benchmarks

[jonaspleyer]

There are two lints which the new Rust edition mentions (see https://doc.rust-lang.org/edition-guide/rust-2024/index.html).

#![warn(missing_unsafe_on_extern, unsafe_op_in_unsafe_fn)]

https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#missing-unsafe-on-extern
https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#unsafe-op-in-unsafe-fn

However, it would mean that we would need to apply these warnings for each crate in the workspace individually.

[alex]

Hmm, is there some way to use workspace settings to enable those warnings universally?

…

On Thu, Mar 13, 2025 at 3:21 PM Jonas Pleyer ***@***.***> wrote: There are two lints which the new Rust edition mentions (see https://doc.rust-lang.org/edition-guide/rust-2024/index.html). #![warn(missing_unsafe_on_extern, unsafe_op_in_unsafe_fn)] https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#missing-unsafe-on-extern https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#unsafe-op-in-unsafe-fn However, it would mean that we would need to apply these warnings for each crate in the workspace individually. — Reply to this email directly, view it on GitHub <#4976 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAAGBDCPJS5CXH4FLFZCC32UHLEBAVCNFSM6AAAAABY674OVSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMRSGQ3DENRYHA> . You are receiving this because you commented.Message ID: ***@***.***> [image: jonaspleyer]*jonaspleyer* left a comment (PyO3/pyo3#4976) <#4976 (comment)> There are two lints which the new Rust edition mentions (see https://doc.rust-lang.org/edition-guide/rust-2024/index.html). #![warn(missing_unsafe_on_extern, unsafe_op_in_unsafe_fn)] https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#missing-unsafe-on-extern https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#unsafe-op-in-unsafe-fn However, it would mean that we would need to apply these warnings for each crate in the workspace individually. — Reply to this email directly, view it on GitHub <#4976 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAAGBDCPJS5CXH4FLFZCC32UHLEBAVCNFSM6AAAAABY674OVSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMRSGQ3DENRYHA> . You are receiving this because you commented.Message ID: ***@***.***>

-- All that is necessary for evil to succeed is for good people to do nothing.

[jonaspleyer]

Benchmarks breakdown

Benchmark BASE HEAD Change
❌ extract_hashbrown_set 16.1 ms 18.4 ms -12.62%

Since my changes have only been semantic, and not changed any functionality or versions of dependecies, this should not have introduced a regression this big. Either the test was an outlier or something else is happening when switching to the new edition and a new compiler version.

[jonaspleyer]

Hmm, is there some way to use workspace settings to enable those warnings universally?

I am not sure about this. I have opened a thread on the users.rust-lang.org forum to see if anyone has a idea on how to do this.
https://users.rust-lang.org/t/warnings-on-workspace-level/126967
I will keep you updated here.

[davidhewitt]

We should be able to configure the lints via the [workspace.lints.rust] setting already present in our Cargo.toml.

[jonaspleyer]

I have rebased the branch to only include the following commits addressing the previously mentioned comments:

• a4c52df mark ffi extern blocks and functions as unsafe
• 866a6c5 mark unsafe function calls with keyword
• e574347 mark unsafe function calls in tests as well

Hmm, is there some way to use workspace settings to enable those warnings
universally?

We should be able to configure the lints via the [workspace.lints.rust] setting already present in our Cargo.toml.

• adf3685 add workspace lints to enhance migration to 2024 edition

[davidhewitt]

Thanks for moving forward with this. cargo fmt needs to be run else the CI won't try further.

I had a quick test and on our MSRV (1.63) unsafe extern is not valid syntax:

error: extern block cannot be declared unsafe
  --> pyo3-ffi/src/abstract_.rs:25:1
   |
25 | unsafe extern "C" {
   | ^^^^^^

... so we may have to drop a4c52df from this PR.

[jonaspleyer]

... so we may have to drop a4c52df from this PR.

I have updated the PR and added another small commit for formatting