diff --git a/RELEASES.md b/RELEASES.md index c0851a1506e13..82a0cda9f6b74 100644 --- a/RELEASES.md +++ b/RELEASES.md @@ -1,3 +1,188 @@ +Rust 1.56.0 (2021-10-21) +======================== + +Language +-------- + +- [The 2021 Edition is now stable.][rust#88100] + See [the edition guide][rust-2021-edition-guide] for more details. +- [You can now specify explicit discriminant values on any Rust enum.][rust#86860] +- [The pattern in `binding @ pattern` can now also introduce new bindings.][rust#85305] +- [Union field access is permitted in `const fn`.][rust#85769] + +[rust-2021-edition-guide]: https://doc.rust-lang.org/nightly/edition-guide/rust-2021/index.html + +Compiler +-------- + +- [Upgrade to LLVM 13.][rust#87570] +- [Support memory, address, and thread sanitizers on aarch64-unknown-freebsd.][rust#88023] +- [Allow specifying an deployment target version for all iOS targets][rust#87699] +- [Warnings can be forced on with `--force-warn`.][rust#87472] + This feature is primarily intended for usage by `cargo fix`, rather than end users. +- [Promote `aarch64-apple-ios-sim` to Tier 2\*.][rust#87760] +- [Add `powerpc-unknown-freebsd` at Tier 3\*.][rust#87370] + +\* Refer to Rust's [platform support page][platform-support-doc] for more +information on Rust's tiered platform support. + +Libraries +--------- + +- [Allow writing of incomplete UTF-8 sequences via stdout/stderr on Windows.][rust#83342] + The Windows console still requires valid Unicode, but this change allows + splitting a UTF-8 character across multiple write calls. This allows, for + instance, programs that just read and write data buffers (e.g. copying a file + to stdout) without regard for Unicode or character boundaries. +- [Prefer `AtomicU{64,128}` over Mutex for Instant backsliding protection.][rust#83093] + For this use case, atomics scale much better under contention. +- [Implement `Extend<(A, B)>` for `(Extend, Extend)`][rust#85835] +- [impl Default, Copy, Clone for std::io::Sink and std::io::Empty][rust#86744] +- [`impl From<[(K, V); N]>` for all collections.][rust#84111] +- [Remove `P: Unpin` bound on impl Future for Pin.][rust#81363] +- [Treat invalid environment variable names as non-existent.][rust#86183] + Previously, the environment functions would panic if given a variable name + with an internal null character or equal sign (`=`). Now, these functions will + just treat such names as non-existent variables, since the OS cannot represent + the existence of a variable with such a name. + +Stabilised APIs +--------------- + +- [`std::os::unix::fs::chroot`] +- [`Iterator::intersperse`] +- [`Iterator::intersperse_with`] +- [`UnsafeCell::raw_get`] +- [`BufWriter::into_parts`] +- [`core::panic::{UnwindSafe, RefUnwindSafe, AssertUnwindSafe}`] + These APIs were previously stable in `std`, but are now also available in `core`. +- [`Vec::shrink_to`] +- [`String::shrink_to`] +- [`OsString::shrink_to`] +- [`PathBuf::shrink_to`] +- [`BinaryHeap::shrink_to`] +- [`VecDeque::shrink_to`] +- [`HashMap::shrink_to`] +- [`HashSet::shrink_to`] +- [`task::ready!`] + +These APIs are now usable in const contexts: + +- [`std::mem::transmute`] +- [`[T]::first`][`slice::first`] +- [`[T]::split_first`][`slice::split_first`] +- [`[T]::last`][`slice::last`] +- [`[T]::split_last`][`slice::split_last`] + +Cargo +----- + +- [Cargo supports specifying a minimum supported Rust version in Cargo.toml.][`rust-version`] + This has no effect at present on dependency version selection. + We encourage crates to specify their minimum supported Rust version, and we encourage CI systems + that support Rust code to include a crate's specified minimum version in the text matrix for that + crate by default. + +Compatibility notes +------------------- + +- [Update to new argument parsing rules on Windows.][rust#87580] + This adjusts Rust's standard library to match the behavior of the standard + libraries for C/C++. The rules have changed slightly over time, and this PR + brings us to the latest set of rules (changed in 2008). +- [Disallow the aapcs calling convention on aarch64][rust#88399] + This was already not supported by LLVM; this change surfaces this lack of + support with a better error message. +- [Make `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` warn by default][rust#87385] +- [Warn when an escaped newline skips multiple lines.][rust#87671] +- [Calls to `libc::getpid` / `std::process::id` from `Command::pre_exec` + may return different values on glibc <= 2.24.][rust#81825] + Rust now invokes the `clone3` system call directly, when available, to use new functionality + available via that system call. Older versions of glibc cache the result of `getpid`, and only + update that cache when calling glibc's clone/fork functions, so a direct system call bypasses + that cache update. glibc 2.25 and newer no longer cache `getpid` for exactly this reason. + +Internal changes +---------------- +These changes provide no direct user facing benefits, but represent significant +improvements to the internals and overall performance of rustc +and related tools. + +- [LLVM is compiled with PGO in published x86_64-unknown-linux-gnu artifacts.][rust#88069] + This improves the performance of most Rust builds. +- [Unify representation of macros in internal data structures.][rust#88019] + This change fixes a host of bugs with the handling of macros by the compiler, + as well as rustdoc. + +[`std::os::unix::fs::chroot`]: https://doc.rust-lang.org/stable/std/os/unix/fs/fn.chroot.html +[`Iterator::intersperse`]: https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.intersperse +[`Iterator::intersperse_with`]: https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.intersperse +[`UnsafeCell::raw_get`]: https://doc.rust-lang.org/stable/std/cell/struct.UnsafeCell.html#method.raw_get +[`BufWriter::into_parts`]: https://doc.rust-lang.org/stable/std/io/struct.BufWriter.html#method.into_parts +[`core::panic::{UnwindSafe, RefUnwindSafe, AssertUnwindSafe}`]: https://github.com/rust-lang/rust/pull/84662 +[`Vec::shrink_to`]: https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.shrink_to +[`String::shrink_to`]: https://doc.rust-lang.org/stable/std/string/struct.String.html#method.shrink_to +[`OsString::shrink_to`]: https://doc.rust-lang.org/stable/std/ffi/struct.OsString.html#method.shrink_to +[`PathBuf::shrink_to`]: https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.shrink_to +[`BinaryHeap::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/struct.BinaryHeap.html#method.shrink_to +[`VecDeque::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/struct.VecDeque.html#method.shrink_to +[`HashMap::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/hash_map/struct.HashMap.html#method.shrink_to +[`HashSet::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/hash_set/struct.HashSet.html#method.shrink_to +[`task::ready!`]: https://doc.rust-lang.org/stable/std/task/macro.ready.html +[`std::mem::transmute`]: https://doc.rust-lang.org/stable/std/mem/fn.transmute.html +[`slice::first`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.first +[`slice::split_first`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_first +[`slice::last`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.last +[`slice::split_last`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_last +[`rust-version`]: https://doc.rust-lang.org/nightly/cargo/reference/manifest.html#the-rust-version-field +[rust#87671]: https://github.com/rust-lang/rust/pull/87671 +[rust#86183]: https://github.com/rust-lang/rust/pull/86183 +[rust#87385]: https://github.com/rust-lang/rust/pull/87385 +[rust#88100]: https://github.com/rust-lang/rust/pull/88100 +[rust#86860]: https://github.com/rust-lang/rust/pull/86860 +[rust#84039]: https://github.com/rust-lang/rust/pull/84039 +[rust#86492]: https://github.com/rust-lang/rust/pull/86492 +[rust#88363]: https://github.com/rust-lang/rust/pull/88363 +[rust#85305]: https://github.com/rust-lang/rust/pull/85305 +[rust#87832]: https://github.com/rust-lang/rust/pull/87832 +[rust#88069]: https://github.com/rust-lang/rust/pull/88069 +[rust#87472]: https://github.com/rust-lang/rust/pull/87472 +[rust#87699]: https://github.com/rust-lang/rust/pull/87699 +[rust#87570]: https://github.com/rust-lang/rust/pull/87570 +[rust#88023]: https://github.com/rust-lang/rust/pull/88023 +[rust#87760]: https://github.com/rust-lang/rust/pull/87760 +[rust#87370]: https://github.com/rust-lang/rust/pull/87370 +[rust#87580]: https://github.com/rust-lang/rust/pull/87580 +[rust#83342]: https://github.com/rust-lang/rust/pull/83342 +[rust#83093]: https://github.com/rust-lang/rust/pull/83093 +[rust#88177]: https://github.com/rust-lang/rust/pull/88177 +[rust#88548]: https://github.com/rust-lang/rust/pull/88548 +[rust#88551]: https://github.com/rust-lang/rust/pull/88551 +[rust#88299]: https://github.com/rust-lang/rust/pull/88299 +[rust#88220]: https://github.com/rust-lang/rust/pull/88220 +[rust#85835]: https://github.com/rust-lang/rust/pull/85835 +[rust#86879]: https://github.com/rust-lang/rust/pull/86879 +[rust#86744]: https://github.com/rust-lang/rust/pull/86744 +[rust#84662]: https://github.com/rust-lang/rust/pull/84662 +[rust#86593]: https://github.com/rust-lang/rust/pull/86593 +[rust#81050]: https://github.com/rust-lang/rust/pull/81050 +[rust#81363]: https://github.com/rust-lang/rust/pull/81363 +[rust#84111]: https://github.com/rust-lang/rust/pull/84111 +[rust#85769]: https://github.com/rust-lang/rust/pull/85769#issuecomment-854363720 +[rust#88490]: https://github.com/rust-lang/rust/pull/88490 +[rust#88269]: https://github.com/rust-lang/rust/pull/88269 +[rust#84176]: https://github.com/rust-lang/rust/pull/84176 +[rust#88399]: https://github.com/rust-lang/rust/pull/88399 +[rust#88227]: https://github.com/rust-lang/rust/pull/88227 +[rust#88200]: https://github.com/rust-lang/rust/pull/88200 +[rust#82776]: https://github.com/rust-lang/rust/pull/82776 +[rust#88077]: https://github.com/rust-lang/rust/pull/88077 +[rust#87728]: https://github.com/rust-lang/rust/pull/87728 +[rust#87050]: https://github.com/rust-lang/rust/pull/87050 +[rust#87619]: https://github.com/rust-lang/rust/pull/87619 +[rust#81825]: https://github.com/rust-lang/rust/pull/81825#issuecomment-808406918 +[rust#88019]: https://github.com/rust-lang/rust/pull/88019 + Version 1.55.0 (2021-09-09) ============================