1.91.0 release notes

Author: Mark-Simulacrum

RELEASES.md

@@ -1,3 +1,214 @@
+Version 1.91.0 (2025-10-30)
+==========================
+
+<a id="1.91.0-Language"></a>
+
+Language
+--------
+
+- [Lower pattern bindings in the order they're written and base drop order on primary bindings' order](https://github.com/rust-lang/rust/pull/143764)
+- [Stabilize declaration of C-style variadic functions for `sysv64`, `win64`, `efiapi`, and `aapcs` ABIs](https://github.com/rust-lang/rust/pull/144066).
+  This brings these ABIs in line with the C ABI: variadic functions can be declared in extern blocks but not defined.
+- [Add `dangling_pointers_from_locals` lint to warn against dangling pointers from local variables](https://github.com/rust-lang/rust/pull/144322)
+- [Upgrade `semicolon_in_expressions_from_macros` from warn to deny](https://github.com/rust-lang/rust/pull/144369)
+- [Stabilize LoongArch32 inline assembly](https://github.com/rust-lang/rust/pull/144402)
+- [Add warn-by-default `integer_to_ptr_transmutes` lint against integer-to-pointer transmutes](https://github.com/rust-lang/rust/pull/144531)
+- [Stabilize `sse4a` and `tbm` target features](https://github.com/rust-lang/rust/pull/144542)
+- [Add `target_env = "macabi"` and `target_env = "sim"` cfgs](https://github.com/rust-lang/rust/pull/139451) as replacements for the `target_abi` cfgs with the same values.
+
+<a id="1.91.0-Compiler"></a>
+
+Compiler
+--------
+
+- [Don't warn on never-to-any `as` casts as unreachable](https://github.com/rust-lang/rust/pull/144804)
+
+<a id="1.91.0-Platform-Support"></a>
+
+Platform Support
+----------------
+
+- [Promote `aarch64-pc-windows-gnullvm` and `x86_64-pc-windows-gnullvm` to Tier 2 with host tools.](https://github.com/rust-lang/rust/pull/143031)
+  Note: llvm-tools and MSI installers are missing but will be added in future releases.
+- [Promote `aarch64-pc-windows-msvc` to Tier 1](https://github.com/rust-lang/rust/pull/145682)
+
+Refer to Rust's [platform support page][platform-support-doc]
+for more information on Rust's tiered platform support.
+
+[platform-support-doc]: https://doc.rust-lang.org/rustc/platform-support.html
+
+<a id="1.91.0-Libraries"></a>
+
+Libraries
+---------
+
+- [Print thread ID in panic message](https://github.com/rust-lang/rust/pull/115746)
+- [Fix overly restrictive lifetime in `core::panic::Location::file` return type](https://github.com/rust-lang/rust/pull/132087)
+- [Guarantee parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp`](https://github.com/rust-lang/rust/pull/139357)
+- [Document assumptions about `Clone` and `Eq` traits](https://github.com/rust-lang/rust/pull/144330/)
+- [`std::thread`: Return error if setting thread stack size fails](https://github.com/rust-lang/rust/pull/144210)
+  This used to panic within the standard library.
+
+<a id="1.91.0-Stabilized-APIs"></a>
+
+Stabilized APIs
+---------------
+
+- [`Path::file_prefix`](https://doc.rust-lang.org/stable/std/path/struct.Path.html#method.file_prefix)
+- [`AtomicPtr::fetch_ptr_add`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_ptr_add)
+- [`AtomicPtr::fetch_ptr_sub`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_ptr_sub)
+- [`AtomicPtr::fetch_byte_add`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_byte_add)
+- [`AtomicPtr::fetch_byte_sub`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_byte_sub)
+- [`AtomicPtr::fetch_or`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_or)
+- [`AtomicPtr::fetch_and`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_and)
+- [`AtomicPtr::fetch_xor`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_xor)
+- [`{integer}::strict_add`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_add)
+- [`{integer}::strict_sub`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_sub)
+- [`{integer}::strict_mul`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_mul)
+- [`{integer}::strict_div`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_div)
+- [`{integer}::strict_div_euclid`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_div_euclid)
+- [`{integer}::strict_rem`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_rem)
+- [`{integer}::strict_rem_euclid`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_rem_euclid)
+- [`{integer}::strict_neg`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_neg)
+- [`{integer}::strict_shl`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_shl)
+- [`{integer}::strict_shr`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_shr)
+- [`{integer}::strict_pow`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_pow)
+- [`i{N}::strict_add_unsigned`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_add_unsigned)
+- [`i{N}::strict_sub_unsigned`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_sub_unsigned)
+- [`i{N}::strict_abs`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_abs)
+- [`u{N}::strict_add_signed`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_add_signed)
+- [`u{N}::strict_sub_signed`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_sub_signed)
+- [`PanicHookInfo::payload_as_str`](https://doc.rust-lang.org/stable/std/panic/struct.PanicHookInfo.html#method.payload_as_str)
+- [`core::iter::chain`](https://doc.rust-lang.org/stable/core/iter/fn.chain.html)
+- [`u{N}::checked_signed_diff`](https://doc.rust-lang.org/stable/std/primitive.u16.html#method.checked_signed_diff)
+- [`core::array::repeat`](https://doc.rust-lang.org/stable/core/array/fn.repeat.html)
+- [`PathBuf::add_extension`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.add_extension)
+- [`PathBuf::with_added_extension`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.with_added_extension)
+- [`Duration::from_mins`](https://doc.rust-lang.org/stable/std/time/struct.Duration.html#method.from_mins)
+- [`Duration::from_hours`](https://doc.rust-lang.org/stable/std/time/struct.Duration.html#method.from_hours)
+- [`impl PartialEq<str> for PathBuf`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#impl-PartialEq%3Cstr%3E-for-PathBuf)
+- [`impl PartialEq<String> for PathBuf`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#impl-PartialEq%3CString%3E-for-PathBuf)
+- [`impl PartialEq<str> for Path`](https://doc.rust-lang.org/stable/std/path/struct.Path.html#impl-PartialEq%3Cstr%3E-for-Path)
+- [`impl PartialEq<String> for Path`](https://doc.rust-lang.org/stable/std/path/struct.Path.html#impl-PartialEq%3CString%3E-for-Path)
+- [`impl PartialEq<PathBuf> for String`](https://doc.rust-lang.org/stable/std/string/struct.String.html#impl-PartialEq%3CPathBuf%3E-for-String)
+- [`impl PartialEq<Path> for String`](https://doc.rust-lang.org/stable/std/string/struct.String.html#impl-PartialEq%3CPath%3E-for-String)
+- [`impl PartialEq<PathBuf> for str`](https://doc.rust-lang.org/stable/std/primitive.str.html#impl-PartialEq%3CPathBuf%3E-for-str)
+- [`impl PartialEq<Path> for str`](https://doc.rust-lang.org/stable/std/primitive.str.html#impl-PartialEq%3CPath%3E-for-str)
+- [`Ipv4Addr::from_octets`](https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.from_octets)
+- [`Ipv6Addr::from_octets`](https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.from_octets)
+- [`Ipv6Addr::from_segments`](https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.from_segments)
+- [`impl<T> Default for Pin<Box<T>> where Box<T>: Default, T: ?Sized`](https://doc.rust-lang.org/stable/std/default/trait.Default.html#impl-Default-for-Pin%3CBox%3CT%3E%3E)
+- [`impl<T> Default for Pin<Rc<T>> where Rc<T>: Default, T: ?Sized`](https://doc.rust-lang.org/stable/std/default/trait.Default.html#impl-Default-for-Pin%3CRc%3CT%3E%3E)
+- [`impl<T> Default for Pin<Arc<T>> where Arc<T>: Default, T: ?Sized`](https://doc.rust-lang.org/stable/std/default/trait.Default.html#impl-Default-for-Pin%3CArc%3CT%3E%3E)
+- [`Cell::as_array_of_cells`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#method.as_array_of_cells)
+- [`u{N}::carrying_add`](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.carrying_add)
+- [`u{N}::borrowing_sub`](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.borrowing_sub)
+- [`u{N}::carrying_mul`](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.carrying_mul)
+- [`u{N}::carrying_mul_add`](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.carrying_mul_add)
+- [`BTreeMap::extract_if`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeMap.html#method.extract_if)
+- [`BTreeSet::extract_if`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeSet.html#method.extract_if)
+- [`impl Debug for windows::ffi::EncodeWide<'_>`](https://doc.rust-lang.org/stable/std/os/windows/ffi/struct.EncodeWide.html#impl-Debug-for-EncodeWide%3C'_%3E)
+- [`str::ceil_char_boundary`](https://doc.rust-lang.org/stable/std/primitive.str.html#method.ceil_char_boundary)
+- [`str::floor_char_boundary`](https://doc.rust-lang.org/stable/std/primitive.str.html#method.floor_char_boundary)
+- [`impl Sum for Saturating<u{N}>`](https://doc.rust-lang.org/stable/std/num/struct.Saturating.html#impl-Sum-for-Saturating%3Cu32%3E)
+- [`impl Sum<&Self> for Saturating<u{N}>`](https://doc.rust-lang.org/stable/std/num/struct.Saturating.html#impl-Sum%3C%26Saturating%3Cu32%3E%3E-for-Saturating%3Cu32%3E)
+- [`impl Product for Saturating<u{N}>`](https://doc.rust-lang.org/stable/std/num/struct.Saturating.html#impl-Product-for-Saturating%3Cu32%3E)
+- [`impl Product<&Self> for Saturating<u{N}>`](https://doc.rust-lang.org/stable/std/num/struct.Saturating.html#impl-Product%3C%26Saturating%3Cu32%3E%3E-for-Saturating%3Cu32%3E)
+
+These previously stable APIs are now stable in const contexts:
+
+- [`<[T; N]>::each_ref`](https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_ref)
+- [`<[T; N]>::each_mut`](https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_mut)
+- [`OsString::new`](https://doc.rust-lang.org/stable/std/ffi/struct.OsString.html#method.new)
+- [`PathBuf::new`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.new)
+- [`TypeId::of`](https://doc.rust-lang.org/stable/std/any/struct.TypeId.html#method.of)
+- [`ptr::with_exposed_provenance`](https://doc.rust-lang.org/stable/std/ptr/fn.with_exposed_provenance.html)
+- [`ptr::with_exposed_provenance_mut`](https://doc.rust-lang.org/stable/std/ptr/fn.with_exposed_provenance_mut.html)
+
+<a id="1.91.0-Cargo"></a>
+
+Cargo
+-----
+
+- 🎉 Stabilize `build.build-dir`.
+  This config sets the directory where intermediate build artifacts are stored.
+  These artifacts are produced by Cargo and rustc during the build process.
+  End users usually won't need to interact with them, and the layout inside
+  `build-dir` is an implementation detail that may change without notice.
+  ([config doc](https://doc.rust-lang.org/stable/cargo/reference/config.html#buildbuild-dir))
+  ([build cache doc](https://doc.rust-lang.org/stable/cargo/reference/build-cache.html))
+  [#15833](https://github.com/rust-lang/cargo/pull/15833)
+  [#15840](https://github.com/rust-lang/cargo/pull/15840)
+- The `--target` flag and the `build.target` configuration can now take literal
+  `"host-tuple"` string, which will internally be substituted by the host
+  machine's target triple.
+  [#15838](https://github.com/rust-lang/cargo/pull/15838)
+  [#16003](https://github.com/rust-lang/cargo/pull/16003)
+  [#16032](https://github.com/rust-lang/cargo/pull/16032)
+
+<a id="1.91.0-Rustdoc"></a>
+
+Rustdoc
+-----
+- [In search results, rank doc aliases lower than non-alias items with the same name](https://github.com/rust-lang/rust/pull/145100)
+- [Raw pointers now work in type-based search like references](https://github.com/rust-lang/rust/pull/145731). This means you can now search for things like `*const u8 ->`, and additionally functions that take or return raw pointers will now display their signature properly in search results.
+
+<a id="1.91.0-Compatibility-Notes"></a>
+
+Compatibility Notes
+-------------------
+
+- [Always require coroutine captures to be drop-live](https://github.com/rust-lang/rust/pull/144156)
+- [Apple: Always pass SDK root when linking with `cc`, and pass it via `SDKROOT` env var](https://github.com/rust-lang/rust/pull/131477). This should fix linking issues with `rustc` running inside Xcode. Libraries in `/usr/local/lib` may no longer be linked automatically, if you develop or use a crate that relies on this, you should explicitly set `cargo::rustc-link-search=/usr/local/lib` in a `build.rs` script.
+- [Relaxed bounds in associated type bound position like in `TraitRef<AssocTy: ?Sized>` are now correctly forbidden](https://github.com/rust-lang/rust/pull/135331)
+- [Add unstable `#[sanitize(xyz = "on|off")]` built-in attribute that shadows procedural macros with the same name](https://github.com/rust-lang/rust/pull/142681)
+- [Fix the drop checker being more permissive for bindings declared with let-else](https://github.com/rust-lang/rust/pull/143028)
+- [Be more strict when parsing attributes, erroring on many invalid attributes](https://github.com/rust-lang/rust/pull/144689)
+    - [Error on invalid `#[should_panic]` attributes](https://github.com/rust-lang/rust/pull/143808)
+    - [Error on invalid `#[link]` attributes](https://github.com/rust-lang/rust/pull/143193)
+- [Mark all deprecation lints in name resolution as deny-by-default and also report in dependencies](https://github.com/rust-lang/rust/pull/143929)
+- The lint `semicolon_in_expressions_from_macros`, for `macro_rules!` macros in expression position that expand to end in a semicolon (`;`), is now deny-by-default. It was already warn-by-default, and a future compatibility warning (FCW) that warned even in dependencies. This lint will become a hard error in the future.
+- [Trait impl modifiers (e.g., `unsafe`, `!`, `default`) in inherent impls are no longer syntactically valid](https://github.com/rust-lang/rust/pull/144386)
+- [Start reporting future breakage for `ill_formed_attribute_input` in dependencies](https://github.com/rust-lang/rust/pull/144544)
+- [Restrict the scope of temporaries created by the macros `pin!`, `format_args!`, `write!`, and `writeln!` in `if let` scrutinees in Rust Edition 2024.](https://github.com/rust-lang/rust/pull/145342) This applies [Rust Edition 2024's `if let` temporary scope rules](https://doc.rust-lang.org/edition-guide/rust-2024/temporary-if-let-scope.html) to these temporaries, which previously could live past the `if` expression regardless of Edition.
+- [Invalid numeric literal suffixes in tuple indexing, tuple struct indexing, and struct field name positions are now correctly rejected](https://github.com/rust-lang/rust/pull/145463)
+- [Closures marked with the keyword `static` are now syntactically invalid](https://github.com/rust-lang/rust/pull/145604)
+- [Shebangs inside `--cfg` and `--check-cfg` arguments are no longer allowed](https://github.com/rust-lang/rust/pull/146211)
+- [Add future incompatibility lint for temporary lifetime shortening in Rust 1.92](https://github.com/rust-lang/rust/pull/147056)
+
+Cargo compatibility notes:
+
+- `cargo publish` no longer keeps `.crate` tarballs as final build artifacts
+  when `build.build-dir` is set. These tarballs were previously included due to
+  an oversight and are now treated as intermediate artifacts.
+  To get `.crate` tarballs as final artifacts, use `cargo package`.
+  In a future version, this change will apply regardless of `build.build-dir`.
+  [#15910](https://github.com/rust-lang/cargo/pull/15910)
+- Adjust Cargo messages to match rustc diagnostic style.
+  This changes some of the terminal colors used by Cargo messages.
+  [#15928](https://github.com/rust-lang/cargo/pull/15928)
+- Tools and projects relying on the
+  [internal details of Cargo's `build-dir`](https://doc.rust-lang.org/cargo/reference/build-cache.html)
+  may not work for users changing their `build-dir` layout.
+  For those doing so, we'd recommend proactively testing these cases
+  particularly as we are considering changing the default location of the `build-dir` in the future
+  ([cargo#16147](https://github.com/rust-lang/cargo/issues/16147)).
+  If you can't migrate off of Cargo's internal details,
+  we'd like to learn more about your use case as we prepare to change the layout of the `build-dir`
+  ([cargo#15010](https://github.com/rust-lang/cargo/issues/15010)).
+
+<a id="1.91.0-Internal-Changes"></a>
+
+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.
+
+- [Update to LLVM 21](https://github.com/rust-lang/rust/pull/143684)
+
+
 Version 1.90.0 (2025-09-18)
 ===========================