v1.87.0

Compare Source

==========================

Language

• Stabilize asm_goto feature
• Allow parsing open beginning ranges (..EXPR) after unary operators !, -, and *.
• Don't require method impls for methods with Self: Sized bounds in impls for unsized types
• Stabilize feature(precise_capturing_in_traits) allowing use<...> bounds on return position impl Trait in traits

Compiler

• x86: make SSE2 required for i686 targets and use it to pass SIMD types

Platform Support

• Remove i586-pc-windows-msvc target

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

Libraries

• Stabilize the anonymous pipe API
• Add support for unbounded left/right shift operations
• Print pointer metadata in Debug impl of raw pointers
• Vec::with_capacity guarantees it allocates with the amount requested, even if Vec::capacity returns a different number.
• Most std::arch intrinsics which don't take pointer arguments can now be called from safe code if the caller has the appropriate target features already enabled (https://github.com/rust-lang/stdarch/pull/1714, https://github.com/rust-lang/stdarch/pull/1716, https://github.com/rust-lang/stdarch/pull/1717)
• Undeprecate env::home_dir
• Denote ControlFlow as #[must_use]
• Macros such as assert_eq! and vec! now support const {...} expressions

Stabilized APIs

• Vec::extract_if
• vec::ExtractIf
• LinkedList::extract_if
• linked_list::ExtractIf
• <[T]>::split_off
• <[T]>::split_off_mut
• <[T]>::split_off_first
• <[T]>::split_off_first_mut
• <[T]>::split_off_last
• <[T]>::split_off_last_mut
• String::extend_from_within
• os_str::Display
• OsString::display
• OsStr::display
• io::pipe
• io::PipeReader
• io::PipeWriter
• impl From<PipeReader> for OwnedHandle
• impl From<PipeWriter> for OwnedHandle
• impl From<PipeReader> for Stdio
• impl From<PipeWriter> for Stdio
• impl From<PipeReader> for OwnedFd
• impl From<PipeWriter> for OwnedFd
• Box<MaybeUninit<T>>::write
• impl TryFrom<Vec<u8>> for String
• <*const T>::offset_from_unsigned
• <*const T>::byte_offset_from_unsigned
• <*mut T>::offset_from_unsigned
• <*mut T>::byte_offset_from_unsigned
• NonNull::offset_from_unsigned
• NonNull::byte_offset_from_unsigned
• <uN>::cast_signed
• NonZero::<uN>::cast_signed.
• <iN>::cast_unsigned.
• NonZero::<iN>::cast_unsigned.
• <uN>::is_multiple_of
• <uN>::unbounded_shl
• <uN>::unbounded_shr
• <iN>::unbounded_shl
• <iN>::unbounded_shr
• <iN>::midpoint
• <str>::from_utf8
• <str>::from_utf8_mut
• <str>::from_utf8_unchecked
• <str>::from_utf8_unchecked_mut

These previously stable APIs are now stable in const contexts:

• core::str::from_utf8_mut
• <[T]>::copy_from_slice
• SocketAddr::set_ip
• SocketAddr::set_port,
• SocketAddrV4::set_ip
• SocketAddrV4::set_port,
• SocketAddrV6::set_ip
• SocketAddrV6::set_port
• SocketAddrV6::set_flowinfo
• SocketAddrV6::set_scope_id
• char::is_digit
• char::is_whitespace
• <[[T; N]]>::as_flattened
• <[[T; N]]>::as_flattened_mut
• String::into_bytes
• String::as_str
• String::capacity
• String::as_bytes
• String::len
• String::is_empty
• String::as_mut_str
• String::as_mut_vec
• Vec::as_ptr
• Vec::as_slice
• Vec::capacity
• Vec::len
• Vec::is_empty
• Vec::as_mut_slice
• Vec::as_mut_ptr

Cargo

• Add terminal integration via ANSI OSC 9;4 sequences
• chore: bump openssl to v3
• feat(package): add --exclude-lockfile flag

Compatibility Notes

• Rust now raises an error for macro invocations inside the #![crate_name] attribute
• Unstable fields are now always considered to be inhabited
• Macro arguments of unary operators followed by open beginning ranges may now be matched differently
• Make Debug impl of raw pointers print metadata if present
• Warn against function pointers using unsupported ABI strings in dependencies
• Associated types on dyn types are no longer deduplicated
• Forbid attributes on .. inside of struct patterns (let Struct { #[attribute] .. }) =
• Make ptr_cast_add_auto_to_object lint into hard error
• Many std::arch intrinsics are now safe to call in some contexts, there may now be new unused_unsafe warnings in existing codebases.
• Limit width and precision formatting options to 16 bits on all targets
• Turn order dependent trait objects future incompat warning into a hard error
• Denote ControlFlow as #[must_use]
• Windows: The standard library no longer links advapi32, except on win7. Code such as C libraries that were relying on this assumption may need to explicitly link advapi32.
• Proc macros can no longer observe expanded cfg(true) attributes.
• Start changing the internal representation of pasted tokens. Certain invalid declarative macros that were previously accepted in obscure circumstances are now correctly rejected by the compiler. Use of a tt fragment specifier can often fix these macros.
• Don't allow flattened format_args in const.

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 20

v1.86.0

Compare Source

==========================

Language

• Stabilize upcasting trait objects to supertraits.
• Allow safe functions to be marked with the #[target_feature] attribute.
• The missing_abi lint now warns-by-default.
• Rust now lints about double negations, to catch cases that might have intended to be a prefix decrement operator (--x) as written in other languages. This was previously a clippy lint, clippy::double_neg, and is now available directly in Rust as double_negations.
• More pointers are now detected as definitely not-null based on their alignment in const eval.
• Empty repr() attribute applied to invalid items are now correctly rejected.
• Inner attributes #![test] and #![rustfmt::skip] are no longer accepted in more places than intended.

Compiler

• Debug-assert that raw pointers are non-null on access.
• Change -O to mean -C opt-level=3 instead of -C opt-level=2 to match Cargo's defaults.
• Fix emission of overflowing_literals under certain macro environments.

Platform Support

• Replace i686-unknown-redox target with i586-unknown-redox.
• Increase baseline CPU of i686-unknown-hurd-gnu to Pentium 4.
• New tier 3 targets:
  • {aarch64-unknown,x86_64-pc}-nto-qnx710_iosock.
    For supporting Neutrino QNX 7.1 with io-socket network stack.
  • {aarch64-unknown,x86_64-pc}-nto-qnx800.
    For supporting Neutrino QNX 8.0 (no_std-only).
  • {x86_64,i686}-win7-windows-gnu.
    Intended for backwards compatibility with Windows 7. {x86_64,i686}-win7-windows-msvc are the Windows MSVC counterparts that already exist as Tier 3 targets.
  • amdgcn-amd-amdhsa.
  • x86_64-pc-cygwin.
  • {mips,mipsel}-mti-none-elf.
    Initial bare-metal support.
  • m68k-unknown-none-elf.
  • armv7a-nuttx-{eabi,eabihf}, aarch64-unknown-nuttx, and thumbv7a-nuttx-{eabi,eabihf}.

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

Libraries

• The type of FromBytesWithNulError in CStr::from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, FromBytesWithNulError> was changed from an opaque struct to an enum, allowing users to examine why the conversion failed.
• Remove RustcDecodable and RustcEncodable.
• Deprecate libtest's --logfile option.
• On recent versions of Windows, std::fs::remove_file will now remove read-only files.

Stabilized APIs

• {float}::next_down
• {float}::next_up
• <[_]>::get_disjoint_mut
• <[_]>::get_disjoint_unchecked_mut
• slice::GetDisjointMutError
• HashMap::get_disjoint_mut
• HashMap::get_disjoint_unchecked_mut
• NonZero::count_ones
• Vec::pop_if
• sync::Once::wait
• sync::Once::wait_force
• sync::OnceLock::wait

These APIs are now stable in const contexts:

• hint::black_box
• io::Cursor::get_mut
• io::Cursor::set_position
• str::is_char_boundary
• str::split_at
• str::split_at_checked
• str::split_at_mut
• str::split_at_mut_checked

Cargo

• When merging, replace rather than combine configuration keys that refer to a program path and its arguments.
• Error if both --package and --workspace are passed but the requested package is missing. This was previously silently ignored, which was considered a bug since missing packages should be reported.
• Deprecate the token argument in cargo login to avoid shell history leaks.
• Simplify the implementation of SourceID comparisons. This may potentially change behavior if the canonicalized URL compares differently in alternative registries.

Rustdoc

• Add a sans-serif font setting.

Compatibility Notes

• The wasm_c_abi future compatibility warning is now a hard error.
  Users of wasm-bindgen should upgrade to at least version 0.2.89, otherwise compilation will fail.
• Remove long-deprecated no-op attributes #![no_start] and #![crate_id].
• The future incompatibility lint cenum_impl_drop_cast has been made into a hard error. This means it is now an error to cast a field-less enum to an integer if the enum implements Drop.
• SSE2 is now required for "i686" 32-bit x86 hard-float targets; disabling it causes a warning that will become a hard error eventually.
  To compile for pre-SSE2 32-bit x86, use a "i586" target instead.

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 the rustc on AArch64 Linux with ThinLTO + PGO.
  The ARM 64-bit compiler (AArch64) on Linux is now optimized with ThinLTO and PGO, similar to the optimizations we have already performed for the x86-64 compiler on Linux. This should make it up to 30% faster.