rust1.85/rust1.85.changes

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Fri Feb 21 05:36:41 UTC 2025 - Xiaoguang Wang <xiaoguang.wang@suse.com>

Version 1.85.0 (2025-02-20)
==========================

Language
--------
- [The 2024 Edition is now stable.](https://github.com/rust-lang/rust/pull/133349)
  See [the edition guide](https://doc.rust-lang.org/nightly/edition-guide/rust-2024/index.html) for more details.
- [Stabilize async closures](https://github.com/rust-lang/rust/pull/132706)
  See [RFC 3668](https://rust-lang.github.io/rfcs/3668-async-closures.html) for more details.
- [Stabilize `#[diagnostic::do_not_recommend]`](https://github.com/rust-lang/rust/pull/132056)
- [Add `unpredictable_function_pointer_comparisons` lint to warn against function pointer comparisons](https://github.com/rust-lang/rust/pull/118833)
- [Lint on combining `#[no_mangle]` and `#[export_name]` attributes.](https://github.com/rust-lang/rust/pull/131558)

Compiler
--------
- [The unstable flag `-Zpolymorphize` has been removed](https://github.com/rust-lang/rust/pull/133883), see https://github.com/rust-lang/compiler-team/issues/810 for some background.

Platform Support
----------------
- [Promote `powerpc64le-unknown-linux-musl` to tier 2 with host tools](https://github.com/rust-lang/rust/pull/133801)

Refer to Rust's [platform support page][platform-support-doc]
for more information on Rust's tiered platform support.

Libraries
---------
- [Panics in the standard library now have a leading `library/` in their path](https://github.com/rust-lang/rust/pull/132390)
- [`std::env::home_dir()` on Windows now ignores the non-standard `$HOME` environment variable](https://github.com/rust-lang/rust/pull/132515)

  It will be un-deprecated in a subsequent release.
- [Add `AsyncFn*` to the prelude in all editions.](https://github.com/rust-lang/rust/pull/132611)

Stabilized APIs
---------------

- [`BuildHasherDefault::new`](https://doc.rust-lang.org/stable/std/hash/struct.BuildHasherDefault.html#method.new)
- [`ptr::fn_addr_eq`](https://doc.rust-lang.org/std/ptr/fn.fn_addr_eq.html)
- [`io::ErrorKind::QuotaExceeded`](https://doc.rust-lang.org/stable/std/io/enum.ErrorKind.html#variant.QuotaExceeded)
- [`io::ErrorKind::CrossesDevices`](https://doc.rust-lang.org/stable/std/io/enum.ErrorKind.html#variant.CrossesDevices)
- [`{float}::midpoint`](https://doc.rust-lang.org/core/primitive.f32.html#method.midpoint)
- [Unsigned `{integer}::midpoint`](https://doc.rust-lang.org/std/primitive.u64.html#method.midpoint)
- [`NonZeroU*::midpoint`](https://doc.rust-lang.org/std/num/type.NonZeroU32.html#method.midpoint)
- [impl `std::iter::Extend` for tuples with arity 1 through 12](https://doc.rust-lang.org/stable/std/iter/trait.Extend.html#impl-Extend%3C(A,)%3E-for-(EA,))
- [`FromIterator<(A, ...)>` for tuples with arity 1 through 12](https://doc.rust-lang.org/stable/std/iter/trait.FromIterator.html#impl-FromIterator%3C(EA,)%3E-for-(A,))
- [`std::task::Waker::noop`](https://doc.rust-lang.org/stable/std/task/struct.Waker.html#method.noop)

These APIs are now stable in const contexts:

- [`mem::size_of_val`](https://doc.rust-lang.org/stable/std/mem/fn.size_of_val.html)
- [`mem::align_of_val`](https://doc.rust-lang.org/stable/std/mem/fn.align_of_val.html)
- [`Layout::for_value`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.for_value)
- [`Layout::align_to`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.align_to)
- [`Layout::pad_to_align`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.pad_to_align)
- [`Layout::extend`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.extend)
- [`Layout::array`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.array)
- [`std::mem::swap`](https://doc.rust-lang.org/stable/std/mem/fn.swap.html)
- [`std::ptr::swap`](https://doc.rust-lang.org/stable/std/ptr/fn.swap.html)
- [`NonNull::new`](https://doc.rust-lang.org/stable/std/ptr/struct.NonNull.html#method.new)
- [`HashMap::with_hasher`](https://doc.rust-lang.org/stable/std/collections/struct.HashMap.html#method.with_hasher)
- [`HashSet::with_hasher`](https://doc.rust-lang.org/stable/std/collections/struct.HashSet.html#method.with_hasher)
- [`BuildHasherDefault::new`](https://doc.rust-lang.org/stable/std/hash/struct.BuildHasherDefault.html#method.new)
- [`<float>::recip`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.recip)
- [`<float>::to_degrees`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.to_degrees)
- [`<float>::to_radians`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.to_radians)
- [`<float>::max`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.max)
- [`<float>::min`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.min)
- [`<float>::clamp`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.clamp)
- [`<float>::abs`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.abs)
- [`<float>::signum`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.signum)
- [`<float>::copysign`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.copysign)
- [`MaybeUninit::write`](https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.write)

Cargo
-----
- [Add future-incompatibility warning against keywords in cfgs and add raw-idents](https://github.com/rust-lang/cargo/pull/14671/)
- [Stabilize higher precedence trailing flags](https://github.com/rust-lang/cargo/pull/14900/)
- [Pass `CARGO_CFG_FEATURE` to build scripts](https://github.com/rust-lang/cargo/pull/14902/)

Rustdoc
-----
- [Doc comment on impl blocks shows the first line, even when the impl block is collapsed](https://github.com/rust-lang/rust/pull/132155)

Compatibility Notes
-------------------
- [`rustc` no longer treats the `test` cfg as a well known check-cfg](https://github.com/rust-lang/rust/pull/131729), instead it is up to the build systems and users of `--check-cfg`[^check-cfg] to set it as a well known cfg using `--check-cfg=cfg(test)`.

  This is done to enable build systems like Cargo to set it conditionally, as not all source files are suitable for unit tests.
  [Cargo (for now) unconditionally sets the `test` cfg as a well known cfg](https://github.com/rust-lang/cargo/pull/14963).
  [^check-cfg]: https://doc.rust-lang.org/nightly/rustc/check-cfg.html
- [Disable potentially incorrect type inference if there are trivial and non-trivial where-clauses](https://github.com/rust-lang/rust/pull/132325)
- `std::env::home_dir()` has been deprecated for years, because it can give surprising results in some Windows configurations if the `HOME` environment variable is set (which is not the normal configuration on Windows). We had previously avoided changing its behavior, out of concern for compatibility with code depending on this non-standard configuration. Given how long this function has been deprecated, we're now fixing its behavior as a bugfix. A subsequent release will remove the deprecation for this function.
- [Make `core::ffi::c_char` signedness more closely match that of the platform-default `char`](https://github.com/rust-lang/rust/pull/132975)

  This changed `c_char` from an `i8` to `u8` or vice versa on many Tier 2 and 3
  targets (mostly Arm and RISC-V embedded targets). The new definition may
  result in compilation failures but fixes compatibility issues with C.

  The `libc` crate matches this change as of its 0.2.169 release.
- [When compiling a nested `macro_rules` macro from an external crate, the content of the inner `macro_rules` is now built with the edition of the external crate, not the local crate.](https://github.com/rust-lang/rust/pull/133274)
- [Increase `sparcv9-sun-solaris` and `x86_64-pc-solaris` Solaris baseline to 11.4.](https://github.com/rust-lang/rust/pull/133293)
- [Show `abi_unsupported_vector_types` lint in future breakage reports](https://github.com/rust-lang/rust/pull/133374)
- [Error if multiple super-trait instantiations of `dyn Trait` need associated types to be specified but only one is provided](https://github.com/rust-lang/rust/pull/133392)
- [Change `powerpc64-ibm-aix` default `codemodel` to large](https://github.com/rust-lang/rust/pull/133811)

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.

- [Build `x86_64-unknown-linux-gnu` with LTO for C/C++ code (e.g., `jemalloc`)](https://github.com/rust-lang/rust/pull/134690)