Rust 1.73.0 pre-release testing

[system]

The 1.73.0 pre-release is ready for testing. The release is scheduled for October 5. Release notes can be found here.

You can try it out locally by running:

RUSTUP_DIST_SERVER=https://dev-static.rust-lang.org rustup update stable

The index is https://dev-static.rust-lang.org/dist/2023-10-03/index.html.

The release team is also thinking about changes to our pre-release process: we'd love your feedback on this GitHub issue.

[Vorpal]

This blob took too long to generate.

Is there a github issue about splitting the file? It is really quite annoying, especially on mobile where I really don't want to view the raw file.

[quinedot]

A copy-paste due to the size limit problem.

---

Version 1.73.0 (2023-10-05)

Language

• Uplift clippy::fn_null_check lint as useless_ptr_null_checks.
• Make noop_method_call warn by default.
• Support interpolated block for try and async in macros.
• Make unconditional_recursion lint detect recursive drops.
• Future compatibility warning for some impls being incorrectly considered not overlapping.
• The invalid_reference_casting lint is now deny-by-default (instead of allow-by-default)

Compiler

• Write version information in a .comment section like GCC/Clang.
• Add documentation on v0 symbol mangling.
• Stabilize extern "thiscall" and "thiscall-unwind" ABIs.
• Only check outlives goals on impl compared to trait.
• Infer type in irrefutable slice patterns with fixed length as array.
• Discard default auto trait impls if explicit ones exist.
• Add several new tier 3 targets:
  • aarch64-unknown-teeos
  • csky-unknown-linux-gnuabiv2
  • riscv64-linux-android
  • riscv64gc-unknown-hermit
  • x86_64-unikraft-linux-musl
  • x86_64-unknown-linux-ohos
• Add wasm32-wasi-preview1-threads as a tier 2 target.

Refer to Rust's platform support page for more information on Rust's tiered platform support.

Libraries

• Add Read, Write and Seek impls for Arc<File>.
• Merge functionality of io::Sink into io::Empty.
• Implement RefUnwindSafe for Backtrace
• Make ExitStatus implement Default
• impl SliceIndex<str> for (Bound<usize>, Bound<usize>)
• Change default panic handler message format.
• Cleaner assert_eq! & assert_ne! panic messages.
• Correct the (deprecated) Android stat struct definitions.

Stabilized APIs

• Unsigned {integer}::div_ceil
• Unsigned {integer}::next_multiple_of
• Unsigned {integer}::checked_next_multiple_of
• std::ffi::FromBytesUntilNulError
• std::os::unix::fs::chown
• std::os::unix::fs::fchown
• std::os::unix::fs::lfchown
• LocalKey::<Cell<T>>::get
• LocalKey::<Cell<T>>::set
• LocalKey::<Cell<T>>::take
• LocalKey::<Cell<T>>::replace
• LocalKey::<RefCell<T>>::with_borrow
• LocalKey::<RefCell<T>>::with_borrow_mut
• LocalKey::<RefCell<T>>::set
• LocalKey::<RefCell<T>>::take
• LocalKey::<RefCell<T>>::replace

These APIs are now stable in const contexts:

• rc::Weak::new
• sync::Weak::new
• NonNull::as_ref

Cargo

• Encode URL params correctly for SourceId in Cargo.lock.
• Bail out an error when using cargo:: in custom build script.

Misc

Compatibility Notes

• Update the minimum external LLVM to 15.
• Check for non-defining uses of return position impl Trait.

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.

• Remove LLVM pointee types, supporting only opaque pointers.
• Port PGO/LTO/BOLT optimized build pipeline to Rust.
• Replace in-tree rustc_apfloat with the new version of the crate.
• Update to LLVM 17.
• Add internal_features lint for internal unstable features.
• Mention style for new syntax in tracking issue template.

[Philippe]

Release notes are also available here: 1.73.0 | Rust Changelogs

[cuviper]

It is fun to see the click-rates on the links here, for a sense of what folks are interested in.

[mjw]

I suggest that the "check for non-defining uses of RPIT" note would benefit from a description that's more directly targetted to Rust programmers in general than the PR's description is.

I can see that there's good reason to believe that nobody will be troubled by this backwards-incompatible change, but I think it would be good if such changes came with reassuring descriptions along the lines of "you won't be affected by this unless you have ...".

[bascule]

{integer}::next_multiple_of is surprisingly popular!

[chrisd]

It's incredibly useful when working with a buffer (and for many kinds of alignment stuff.really). It would definitely be one of may favourite things from this release!

[jhpratt]

When me and Josh were first discussing int_roundings, I had to ask why he wanted that. He said block sizes, which was incredibly easy to understand the use case.

I'm just hoping we can get div_floor and the methods on signed integers faster than it took this to stabilize