diff options
Diffstat (limited to 'library/core/src')
| -rw-r--r-- | library/core/src/fmt/rt.rs | 9 | ||||
| -rw-r--r-- | library/core/src/future/async_drop.rs | 311 | ||||
| -rw-r--r-- | library/core/src/future/mod.rs | 3 | ||||
| -rw-r--r-- | library/core/src/intrinsics/mod.rs | 2 | ||||
| -rw-r--r-- | library/core/src/lib.rs | 1 | ||||
| -rw-r--r-- | library/core/src/ops/drop.rs | 7 | ||||
| -rw-r--r-- | library/core/src/ops/index.rs | 2 | ||||
| -rw-r--r-- | library/core/src/ops/mod.rs | 1 | ||||
| -rw-r--r-- | library/core/src/panicking.rs | 94 | ||||
| -rw-r--r-- | library/core/src/pin.rs | 2 | ||||
| -rw-r--r-- | library/core/src/ptr/const_ptr.rs | 11 | ||||
| -rw-r--r-- | library/core/src/ptr/mut_ptr.rs | 14 | ||||
| -rw-r--r-- | library/core/src/ptr/non_null.rs | 8 | ||||
| -rw-r--r-- | library/core/src/slice/iter.rs | 1 | ||||
| -rw-r--r-- | library/core/src/slice/mod.rs | 133 | ||||
| -rw-r--r-- | library/core/src/str/mod.rs | 2 | ||||
| -rw-r--r-- | library/core/src/sync/atomic.rs | 94 |
17 files changed, 330 insertions, 365 deletions
diff --git a/library/core/src/fmt/rt.rs b/library/core/src/fmt/rt.rs index adcfdd309b7..e409771362e 100644 --- a/library/core/src/fmt/rt.rs +++ b/library/core/src/fmt/rt.rs @@ -200,8 +200,15 @@ impl Argument<'_> { /// let f = format_args!("{}", "a"); /// println!("{f}"); /// ``` + /// + /// This function should _not_ be const, to make sure we don't accept + /// format_args!() and panic!() with arguments in const, even when not evaluated: + /// + /// ```compile_fail,E0015 + /// const _: () = if false { panic!("a {}", "a") }; + /// ``` #[inline] - pub const fn none() -> [Self; 0] { + pub fn none() -> [Self; 0] { [] } } diff --git a/library/core/src/future/async_drop.rs b/library/core/src/future/async_drop.rs index f1778a4d782..fc4f95a98b4 100644 --- a/library/core/src/future/async_drop.rs +++ b/library/core/src/future/async_drop.rs @@ -1,284 +1,51 @@ #![unstable(feature = "async_drop", issue = "126482")] -use crate::fmt; -use crate::future::{Future, IntoFuture}; -use crate::intrinsics::discriminant_value; -use crate::marker::{DiscriminantKind, PhantomPinned}; -use crate::mem::MaybeUninit; -use crate::pin::Pin; -use crate::task::{Context, Poll, ready}; - -/// Asynchronously drops a value by running `AsyncDrop::async_drop` -/// on a value and its fields recursively. -#[unstable(feature = "async_drop", issue = "126482")] -pub fn async_drop<T>(value: T) -> AsyncDropOwning<T> { - AsyncDropOwning { value: MaybeUninit::new(value), dtor: None, _pinned: PhantomPinned } -} - -/// A future returned by the [`async_drop`]. -#[unstable(feature = "async_drop", issue = "126482")] -pub struct AsyncDropOwning<T> { - value: MaybeUninit<T>, - dtor: Option<AsyncDropInPlace<T>>, - _pinned: PhantomPinned, -} - -#[unstable(feature = "async_drop", issue = "126482")] -impl<T> fmt::Debug for AsyncDropOwning<T> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("AsyncDropOwning").finish_non_exhaustive() - } -} - -#[unstable(feature = "async_drop", issue = "126482")] -impl<T> Future for AsyncDropOwning<T> { - type Output = (); - - fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> { - // SAFETY: Self is pinned thus it is ok to store references to self - unsafe { - let this = self.get_unchecked_mut(); - let dtor = Pin::new_unchecked( - this.dtor.get_or_insert_with(|| async_drop_in_place(this.value.as_mut_ptr())), - ); - // AsyncDestuctors are idempotent so Self gets idempotency as well - dtor.poll(cx) - } - } -} +#[allow(unused_imports)] +use core::future::Future; -#[lang = "async_drop_in_place"] -#[allow(unconditional_recursion)] -// FIXME: Consider if `#[rustc_diagnostic_item = "ptr_drop_in_place"]` is needed? -unsafe fn async_drop_in_place_raw<T: ?Sized>( - to_drop: *mut T, -) -> <T as AsyncDestruct>::AsyncDestructor { - // Code here does not matter - this is replaced by the - // real async drop glue constructor by the compiler. - - // SAFETY: see comment above - unsafe { async_drop_in_place_raw(to_drop) } -} +#[allow(unused_imports)] +use crate::pin::Pin; +#[allow(unused_imports)] +use crate::task::{Context, Poll}; -/// Creates the asynchronous destructor of the pointed-to value. -/// -/// # Safety -/// -/// Behavior is undefined if any of the following conditions are violated: -/// -/// * `to_drop` must be [valid](crate::ptr#safety) for both reads and writes. -/// -/// * `to_drop` must be properly aligned, even if `T` has size 0. +/// Async version of Drop trait. /// -/// * `to_drop` must be nonnull, even if `T` has size 0. +/// When a value is no longer needed, Rust will run a "destructor" on that value. +/// The most common way that a value is no longer needed is when it goes out of +/// scope. Destructors may still run in other circumstances, but we're going to +/// focus on scope for the examples here. To learn about some of those other cases, +/// please see [the reference] section on destructors. /// -/// * The value `to_drop` points to must be valid for async dropping, -/// which may mean it must uphold additional invariants. These -/// invariants depend on the type of the value being dropped. For -/// instance, when dropping a Box, the box's pointer to the heap must -/// be valid. +/// [the reference]: https://doc.rust-lang.org/reference/destructors.html /// -/// * While `async_drop_in_place` is executing or the returned async -/// destructor is alive, the only way to access parts of `to_drop` -/// is through the `self: Pin<&mut Self>` references supplied to -/// the `AsyncDrop::async_drop` methods that `async_drop_in_place` -/// or `AsyncDropInPlace<T>::poll` invokes. This usually means the -/// returned future stores the `to_drop` pointer and user is required -/// to guarantee that dropped value doesn't move. +/// ## `Copy` and ([`Drop`]|`AsyncDrop`) are exclusive /// -#[unstable(feature = "async_drop", issue = "126482")] -pub unsafe fn async_drop_in_place<T: ?Sized>(to_drop: *mut T) -> AsyncDropInPlace<T> { - // SAFETY: `async_drop_in_place_raw` has the same safety requirements - unsafe { AsyncDropInPlace(async_drop_in_place_raw(to_drop)) } -} - -/// A future returned by the [`async_drop_in_place`]. -#[unstable(feature = "async_drop", issue = "126482")] -pub struct AsyncDropInPlace<T: ?Sized>(<T as AsyncDestruct>::AsyncDestructor); - -#[unstable(feature = "async_drop", issue = "126482")] -impl<T: ?Sized> fmt::Debug for AsyncDropInPlace<T> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("AsyncDropInPlace").finish_non_exhaustive() - } -} - -#[unstable(feature = "async_drop", issue = "126482")] -impl<T: ?Sized> Future for AsyncDropInPlace<T> { - type Output = (); - - #[inline(always)] - fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> { - // SAFETY: This code simply forwards poll call to the inner future - unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) }.poll(cx) - } -} - -// FIXME(zetanumbers): Add same restrictions on AsyncDrop impls as -// with Drop impls -/// Custom code within the asynchronous destructor. +/// You cannot implement both [`Copy`] and ([`Drop`]|`AsyncDrop`) on the same type. Types that +/// are `Copy` get implicitly duplicated by the compiler, making it very +/// hard to predict when, and how often destructors will be executed. As such, +/// these types cannot have destructors. +#[cfg(not(bootstrap))] #[unstable(feature = "async_drop", issue = "126482")] #[lang = "async_drop"] pub trait AsyncDrop { - /// A future returned by the [`AsyncDrop::async_drop`] to be part - /// of the async destructor. - #[unstable(feature = "async_drop", issue = "126482")] - type Dropper<'a>: Future<Output = ()> - where - Self: 'a; - - /// Constructs the asynchronous destructor for this type. - #[unstable(feature = "async_drop", issue = "126482")] - fn async_drop(self: Pin<&mut Self>) -> Self::Dropper<'_>; -} - -#[lang = "async_destruct"] -#[rustc_deny_explicit_impl] -#[rustc_do_not_implement_via_object] -trait AsyncDestruct { - type AsyncDestructor: Future<Output = ()>; -} - -/// Basically calls `AsyncDrop::async_drop` with pointer. Used to simplify -/// generation of the code for `async_drop_in_place_raw` -#[lang = "surface_async_drop_in_place"] -async unsafe fn surface_async_drop_in_place<T: AsyncDrop + ?Sized>(ptr: *mut T) { - // SAFETY: We call this from async drop `async_drop_in_place_raw` - // which has the same safety requirements - unsafe { <T as AsyncDrop>::async_drop(Pin::new_unchecked(&mut *ptr)).await } -} - -/// Basically calls `Drop::drop` with pointer. Used to simplify generation -/// of the code for `async_drop_in_place_raw` -#[allow(drop_bounds)] -#[lang = "async_drop_surface_drop_in_place"] -async unsafe fn surface_drop_in_place<T: Drop + ?Sized>(ptr: *mut T) { - // SAFETY: We call this from async drop `async_drop_in_place_raw` - // which has the same safety requirements - unsafe { crate::ops::fallback_surface_drop(&mut *ptr) } -} - -/// Wraps a future to continue outputting `Poll::Ready(())` once after -/// wrapped future completes by returning `Poll::Ready(())` on poll. This -/// is useful for constructing async destructors to guarantee this -/// "fuse" property -// -// FIXME: Consider optimizing combinators to not have to use fuse in majority -// of cases, perhaps by adding `#[(rustc_)idempotent(_future)]` attribute for -// async functions and blocks with the unit return type. However current layout -// optimizations currently encode `None` case into the async block's discriminant. -struct Fuse<T> { - inner: Option<T>, -} - -#[lang = "async_drop_fuse"] -fn fuse<T>(inner: T) -> Fuse<T> { - Fuse { inner: Some(inner) } -} - -impl<T> Future for Fuse<T> -where - T: Future<Output = ()>, -{ - type Output = (); - - fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> { - // SAFETY: pin projection into `self.inner` - unsafe { - let this = self.get_unchecked_mut(); - if let Some(inner) = &mut this.inner { - ready!(Pin::new_unchecked(inner).poll(cx)); - this.inner = None; - } - } - Poll::Ready(()) - } -} - -/// Async destructor for arrays and slices. -#[lang = "async_drop_slice"] -async unsafe fn slice<T>(s: *mut [T]) { - let len = s.len(); - let ptr = s.as_mut_ptr(); - for i in 0..len { - // SAFETY: we iterate over elements of `s` slice - unsafe { async_drop_in_place_raw(ptr.add(i)).await } - } -} - -/// Constructs a chain of two futures, which awaits them sequentially as -/// a future. -#[lang = "async_drop_chain"] -async fn chain<F, G>(first: F, last: G) -where - F: IntoFuture<Output = ()>, - G: IntoFuture<Output = ()>, -{ - first.await; - last.await; -} - -/// Basically a lazy version of `async_drop_in_place`. Returns a future -/// that would call `AsyncDrop::async_drop` on a first poll. -/// -/// # Safety -/// -/// Same as `async_drop_in_place` except is lazy to avoid creating -/// multiple mutable references. -#[lang = "async_drop_defer"] -async unsafe fn defer<T: ?Sized>(to_drop: *mut T) { - // SAFETY: same safety requirements as `async_drop_in_place` - unsafe { async_drop_in_place(to_drop) }.await -} - -/// If `T`'s discriminant is equal to the stored one then awaits `M` -/// otherwise awaits the `O`. -/// -/// # Safety -/// -/// Users should carefully manage the returned future, since it would -/// try creating an immutable reference from `this` and get pointee's -/// discriminant. -// FIXME(zetanumbers): Send and Sync impls -#[lang = "async_drop_either"] -async unsafe fn either<O: IntoFuture<Output = ()>, M: IntoFuture<Output = ()>, T>( - other: O, - matched: M, - this: *mut T, - discr: <T as DiscriminantKind>::Discriminant, -) { - // SAFETY: Guaranteed by the safety section of this funtion's documentation - if unsafe { discriminant_value(&*this) } == discr { - drop(other); - matched.await - } else { - drop(matched); - other.await - } -} - -#[lang = "async_drop_deferred_drop_in_place"] -async unsafe fn deferred_drop_in_place<T>(to_drop: *mut T) { - // SAFETY: same safety requirements as with drop_in_place (implied by - // function's name) - unsafe { crate::ptr::drop_in_place(to_drop) } -} - -/// Used for noop async destructors. We don't use [`core::future::Ready`] -/// because it panics after its second poll, which could be potentially -/// bad if that would happen during the cleanup. -#[derive(Clone, Copy)] -struct Noop; - -#[lang = "async_drop_noop"] -fn noop() -> Noop { - Noop -} - -impl Future for Noop { - type Output = (); - - fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Self::Output> { - Poll::Ready(()) - } + /// Executes the async destructor for this type. + /// + /// This method is called implicitly when the value goes out of scope, + /// and cannot be called explicitly. + /// + /// When this method has been called, `self` has not yet been deallocated. + /// That only happens after the method is over. + /// + /// # Panics + #[allow(async_fn_in_trait)] + async fn drop(self: Pin<&mut Self>); +} + +/// Async drop. +#[cfg(not(bootstrap))] +#[unstable(feature = "async_drop", issue = "126482")] +#[lang = "async_drop_in_place"] +pub async unsafe fn async_drop_in_place<T: ?Sized>(_to_drop: *mut T) { + // Code here does not matter - this is replaced by the + // real implementation by the compiler. } diff --git a/library/core/src/future/mod.rs b/library/core/src/future/mod.rs index 65c0171c88d..4b5a2f34d3f 100644 --- a/library/core/src/future/mod.rs +++ b/library/core/src/future/mod.rs @@ -20,8 +20,9 @@ mod pending; mod poll_fn; mod ready; +#[cfg(not(bootstrap))] #[unstable(feature = "async_drop", issue = "126482")] -pub use async_drop::{AsyncDrop, AsyncDropInPlace, async_drop, async_drop_in_place}; +pub use async_drop::{AsyncDrop, async_drop_in_place}; #[stable(feature = "into_future", since = "1.64.0")] pub use into_future::IntoFuture; #[stable(feature = "future_readiness_fns", since = "1.48.0")] diff --git a/library/core/src/intrinsics/mod.rs b/library/core/src/intrinsics/mod.rs index a7563f918a2..c5d5bc000f1 100644 --- a/library/core/src/intrinsics/mod.rs +++ b/library/core/src/intrinsics/mod.rs @@ -2996,7 +2996,7 @@ pub unsafe fn nontemporal_store<T>(ptr: *mut T, val: T); #[rustc_intrinsic] pub const unsafe fn ptr_offset_from<T>(ptr: *const T, base: *const T) -> isize; -/// See documentation of `<*const T>::sub_ptr` for details. +/// See documentation of `<*const T>::offset_from_unsigned` for details. #[rustc_nounwind] #[rustc_intrinsic] #[rustc_intrinsic_const_stable_indirect] diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index 9625475e617..64a7ec8906b 100644 --- a/library/core/src/lib.rs +++ b/library/core/src/lib.rs @@ -118,7 +118,6 @@ #![feature(ptr_metadata)] #![feature(set_ptr_value)] #![feature(slice_as_array)] -#![feature(slice_as_chunks)] #![feature(slice_ptr_get)] #![feature(str_internals)] #![feature(str_split_inclusive_remainder)] diff --git a/library/core/src/ops/drop.rs b/library/core/src/ops/drop.rs index e024b7fb4d3..5d040804a8d 100644 --- a/library/core/src/ops/drop.rs +++ b/library/core/src/ops/drop.rs @@ -240,10 +240,3 @@ pub trait Drop { #[stable(feature = "rust1", since = "1.0.0")] fn drop(&mut self); } - -/// Fallback function to call surface level `Drop::drop` function -#[allow(drop_bounds)] -#[lang = "fallback_surface_drop"] -pub(crate) fn fallback_surface_drop<T: Drop + ?Sized>(x: &mut T) { - <T as Drop>::drop(x) -} diff --git a/library/core/src/ops/index.rs b/library/core/src/ops/index.rs index 37d9a28fb99..8106c088f0b 100644 --- a/library/core/src/ops/index.rs +++ b/library/core/src/ops/index.rs @@ -67,6 +67,7 @@ pub trait Index<Idx: ?Sized> { /// /// May panic if the index is out of bounds. #[stable(feature = "rust1", since = "1.0.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[track_caller] fn index(&self, index: Idx) -> &Self::Output; } @@ -171,6 +172,7 @@ pub trait IndexMut<Idx: ?Sized>: Index<Idx> { /// /// May panic if the index is out of bounds. #[stable(feature = "rust1", since = "1.0.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[track_caller] fn index_mut(&mut self, index: Idx) -> &mut Self::Output; } diff --git a/library/core/src/ops/mod.rs b/library/core/src/ops/mod.rs index 627a875d9f7..1658f0e5a36 100644 --- a/library/core/src/ops/mod.rs +++ b/library/core/src/ops/mod.rs @@ -176,7 +176,6 @@ pub use self::deref::Receiver; pub use self::deref::{Deref, DerefMut}; #[stable(feature = "rust1", since = "1.0.0")] pub use self::drop::Drop; -pub(crate) use self::drop::fallback_surface_drop; #[stable(feature = "rust1", since = "1.0.0")] pub use self::function::{Fn, FnMut, FnOnce}; #[stable(feature = "rust1", since = "1.0.0")] diff --git a/library/core/src/panicking.rs b/library/core/src/panicking.rs index 33ad59916e3..83a45436b30 100644 --- a/library/core/src/panicking.rs +++ b/library/core/src/panicking.rs @@ -155,30 +155,26 @@ pub const fn panic(expr: &'static str) -> ! { // reducing binary size impact. macro_rules! panic_const { ($($lang:ident = $message:expr,)+) => { - pub mod panic_const { - use super::*; - - $( - /// This is a panic called with a message that's a result of a MIR-produced Assert. - // - // never inline unless panic_immediate_abort to avoid code - // bloat at the call sites as much as possible - #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)] - #[cfg_attr(feature = "panic_immediate_abort", inline)] - #[track_caller] - #[rustc_const_stable_indirect] // must follow stable const rules since it is exposed to stable - #[lang = stringify!($lang)] - pub const fn $lang() -> ! { - // Use Arguments::new_const instead of format_args!("{expr}") to potentially - // reduce size overhead. The format_args! macro uses str's Display trait to - // write expr, which calls Formatter::pad, which must accommodate string - // truncation and padding (even though none is used here). Using - // Arguments::new_const may allow the compiler to omit Formatter::pad from the - // output binary, saving up to a few kilobytes. - panic_fmt(fmt::Arguments::new_const(&[$message])); - } - )+ - } + $( + /// This is a panic called with a message that's a result of a MIR-produced Assert. + // + // never inline unless panic_immediate_abort to avoid code + // bloat at the call sites as much as possible + #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)] + #[cfg_attr(feature = "panic_immediate_abort", inline)] + #[track_caller] + #[rustc_const_stable_indirect] // must follow stable const rules since it is exposed to stable + #[lang = stringify!($lang)] + pub const fn $lang() -> ! { + // Use Arguments::new_const instead of format_args!("{expr}") to potentially + // reduce size overhead. The format_args! macro uses str's Display trait to + // write expr, which calls Formatter::pad, which must accommodate string + // truncation and padding (even though none is used here). Using + // Arguments::new_const may allow the compiler to omit Formatter::pad from the + // output binary, saving up to a few kilobytes. + panic_fmt(fmt::Arguments::new_const(&[$message])); + } + )+ } } @@ -186,25 +182,37 @@ macro_rules! panic_const { // slightly different forms. It's not clear if there's a good way to deduplicate without adding // special cases to the compiler (e.g., a const generic function wouldn't have a single definition // shared across crates, which is exactly what we want here). -panic_const! { - panic_const_add_overflow = "attempt to add with overflow", - panic_const_sub_overflow = "attempt to subtract with overflow", - panic_const_mul_overflow = "attempt to multiply with overflow", - panic_const_div_overflow = "attempt to divide with overflow", - panic_const_rem_overflow = "attempt to calculate the remainder with overflow", - panic_const_neg_overflow = "attempt to negate with overflow", - panic_const_shr_overflow = "attempt to shift right with overflow", - panic_const_shl_overflow = "attempt to shift left with overflow", - panic_const_div_by_zero = "attempt to divide by zero", - panic_const_rem_by_zero = "attempt to calculate the remainder with a divisor of zero", - panic_const_coroutine_resumed = "coroutine resumed after completion", - panic_const_async_fn_resumed = "`async fn` resumed after completion", - panic_const_async_gen_fn_resumed = "`async gen fn` resumed after completion", - panic_const_gen_fn_none = "`gen fn` should just keep returning `None` after completion", - panic_const_coroutine_resumed_panic = "coroutine resumed after panicking", - panic_const_async_fn_resumed_panic = "`async fn` resumed after panicking", - panic_const_async_gen_fn_resumed_panic = "`async gen fn` resumed after panicking", - panic_const_gen_fn_none_panic = "`gen fn` should just keep returning `None` after panicking", +pub mod panic_const { + use super::*; + panic_const! { + panic_const_add_overflow = "attempt to add with overflow", + panic_const_sub_overflow = "attempt to subtract with overflow", + panic_const_mul_overflow = "attempt to multiply with overflow", + panic_const_div_overflow = "attempt to divide with overflow", + panic_const_rem_overflow = "attempt to calculate the remainder with overflow", + panic_const_neg_overflow = "attempt to negate with overflow", + panic_const_shr_overflow = "attempt to shift right with overflow", + panic_const_shl_overflow = "attempt to shift left with overflow", + panic_const_div_by_zero = "attempt to divide by zero", + panic_const_rem_by_zero = "attempt to calculate the remainder with a divisor of zero", + panic_const_coroutine_resumed = "coroutine resumed after completion", + panic_const_async_fn_resumed = "`async fn` resumed after completion", + panic_const_async_gen_fn_resumed = "`async gen fn` resumed after completion", + panic_const_gen_fn_none = "`gen fn` should just keep returning `None` after completion", + panic_const_coroutine_resumed_panic = "coroutine resumed after panicking", + panic_const_async_fn_resumed_panic = "`async fn` resumed after panicking", + panic_const_async_gen_fn_resumed_panic = "`async gen fn` resumed after panicking", + panic_const_gen_fn_none_panic = "`gen fn` should just keep returning `None` after panicking", + } + // Separated panic constants list for async drop feature + // (May be joined when the corresponding lang items will be in the bootstrap) + #[cfg(not(bootstrap))] + panic_const! { + panic_const_coroutine_resumed_drop = "coroutine resumed after async drop", + panic_const_async_fn_resumed_drop = "`async fn` resumed after async drop", + panic_const_async_gen_fn_resumed_drop = "`async gen fn` resumed after async drop", + panic_const_gen_fn_none_drop = "`gen fn` resumed after async drop", + } } /// Like `panic`, but without unwinding and track_caller to reduce the impact on codesize on the caller. diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs index 9e6acf04bf7..dd1c2f2c285 100644 --- a/library/core/src/pin.rs +++ b/library/core/src/pin.rs @@ -676,7 +676,7 @@ //! let data_ptr = unpinned_src.data.as_ptr() as *const u8; //! let slice_ptr = unpinned_src.slice.as_ptr() as *const u8; //! let offset = slice_ptr.offset_from(data_ptr) as usize; -//! let len = (*unpinned_src.slice.as_ptr()).len(); +//! let len = unpinned_src.slice.as_ptr().len(); //! //! unpinned_self.slice = NonNull::from(&mut unpinned_self.data[offset..offset+len]); //! } diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs index 2d869958b85..5234fb83eb6 100644 --- a/library/core/src/ptr/const_ptr.rs +++ b/library/core/src/ptr/const_ptr.rs @@ -484,8 +484,9 @@ impl<T: ?Sized> *const T { /// /// This operation itself is always safe, but using the resulting pointer is not. /// - /// The resulting pointer "remembers" the [allocated object] that `self` points to; it must not - /// be used to read or write other allocated objects. + /// The resulting pointer "remembers" the [allocated object] that `self` points to + /// (this is called "[Provenance](ptr/index.html#provenance)"). + /// The pointer must not be used to read or write other allocated objects. /// /// In other words, `let z = x.wrapping_offset((y as isize) - (x as isize))` does *not* make `z` /// the same as `y` even if we assume `T` has size `1` and there is no overflow: `z` is still @@ -804,8 +805,8 @@ impl<T: ?Sized> *const T { /// units of **bytes**. /// /// This is purely a convenience for casting to a `u8` pointer and - /// using [`sub_ptr`][pointer::offset_from_unsigned] on it. See that method for - /// documentation and safety requirements. + /// using [`offset_from_unsigned`][pointer::offset_from_unsigned] on it. + /// See that method for documentation and safety requirements. /// /// For non-`Sized` pointees this operation considers only the data pointers, /// ignoring the metadata. @@ -814,7 +815,7 @@ impl<T: ?Sized> *const T { #[inline] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn byte_offset_from_unsigned<U: ?Sized>(self, origin: *const U) -> usize { - // SAFETY: the caller must uphold the safety contract for `sub_ptr`. + // SAFETY: the caller must uphold the safety contract for `offset_from_unsigned`. unsafe { self.cast::<u8>().offset_from_unsigned(origin.cast::<u8>()) } } diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs index df49eedb350..31b8d3b572c 100644 --- a/library/core/src/ptr/mut_ptr.rs +++ b/library/core/src/ptr/mut_ptr.rs @@ -482,8 +482,9 @@ impl<T: ?Sized> *mut T { /// /// This operation itself is always safe, but using the resulting pointer is not. /// - /// The resulting pointer "remembers" the [allocated object] that `self` points to; it must not - /// be used to read or write other allocated objects. + /// The resulting pointer "remembers" the [allocated object] that `self` points to + /// (this is called "[Provenance](ptr/index.html#provenance)"). + /// The pointer must not be used to read or write other allocated objects. /// /// In other words, `let z = x.wrapping_offset((y as isize) - (x as isize))` does *not* make `z` /// the same as `y` even if we assume `T` has size `1` and there is no overflow: `z` is still @@ -937,6 +938,7 @@ impl<T: ?Sized> *mut T { /// /// // This would be incorrect, as the pointers are not correctly ordered: /// // ptr1.offset_from(ptr2) + /// ``` #[stable(feature = "ptr_sub_ptr", since = "1.87.0")] #[rustc_const_stable(feature = "const_ptr_sub_ptr", since = "1.87.0")] #[inline] @@ -945,7 +947,7 @@ impl<T: ?Sized> *mut T { where T: Sized, { - // SAFETY: the caller must uphold the safety contract for `sub_ptr`. + // SAFETY: the caller must uphold the safety contract for `offset_from_unsigned`. unsafe { (self as *const T).offset_from_unsigned(origin) } } @@ -954,8 +956,8 @@ impl<T: ?Sized> *mut T { /// units of **bytes**. /// /// This is purely a convenience for casting to a `u8` pointer and - /// using [`sub_ptr`][pointer::offset_from_unsigned] on it. See that method for - /// documentation and safety requirements. + /// using [`offset_from_unsigned`][pointer::offset_from_unsigned] on it. + /// See that method for documentation and safety requirements. /// /// For non-`Sized` pointees this operation considers only the data pointers, /// ignoring the metadata. @@ -964,7 +966,7 @@ impl<T: ?Sized> *mut T { #[inline] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn byte_offset_from_unsigned<U: ?Sized>(self, origin: *mut U) -> usize { - // SAFETY: the caller must uphold the safety contract for `byte_sub_ptr`. + // SAFETY: the caller must uphold the safety contract for `byte_offset_from_unsigned`. unsafe { (self as *const T).byte_offset_from_unsigned(origin) } } diff --git a/library/core/src/ptr/non_null.rs b/library/core/src/ptr/non_null.rs index 68b8f0c3e4e..0864cc457b6 100644 --- a/library/core/src/ptr/non_null.rs +++ b/library/core/src/ptr/non_null.rs @@ -906,7 +906,7 @@ impl<T: ?Sized> NonNull<T> { where T: Sized, { - // SAFETY: the caller must uphold the safety contract for `sub_ptr`. + // SAFETY: the caller must uphold the safety contract for `offset_from_unsigned`. unsafe { self.as_ptr().offset_from_unsigned(subtracted.as_ptr()) } } @@ -915,8 +915,8 @@ impl<T: ?Sized> NonNull<T> { /// units of **bytes**. /// /// This is purely a convenience for casting to a `u8` pointer and - /// using [`sub_ptr`][NonNull::offset_from_unsigned] on it. See that method for - /// documentation and safety requirements. + /// using [`offset_from_unsigned`][NonNull::offset_from_unsigned] on it. + /// See that method for documentation and safety requirements. /// /// For non-`Sized` pointees this operation considers only the data pointers, /// ignoring the metadata. @@ -925,7 +925,7 @@ impl<T: ?Sized> NonNull<T> { #[stable(feature = "ptr_sub_ptr", since = "1.87.0")] #[rustc_const_stable(feature = "const_ptr_sub_ptr", since = "1.87.0")] pub const unsafe fn byte_offset_from_unsigned<U: ?Sized>(self, origin: NonNull<U>) -> usize { - // SAFETY: the caller must uphold the safety contract for `byte_sub_ptr`. + // SAFETY: the caller must uphold the safety contract for `byte_offset_from_unsigned`. unsafe { self.as_ptr().byte_offset_from_unsigned(origin.as_ptr()) } } diff --git a/library/core/src/slice/iter.rs b/library/core/src/slice/iter.rs index f507ee563ac..85a5e89a49e 100644 --- a/library/core/src/slice/iter.rs +++ b/library/core/src/slice/iter.rs @@ -2335,7 +2335,6 @@ pub struct ArrayChunks<'a, T: 'a, const N: usize> { impl<'a, T, const N: usize> ArrayChunks<'a, T, N> { #[rustc_const_unstable(feature = "const_slice_make_iter", issue = "137737")] - // #[rustc_const_unstable(feature = "slice_as_chunks", issue = "74985")] #[inline] pub(super) const fn new(slice: &'a [T]) -> Self { let (array_slice, rem) = slice.as_chunks(); diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs index 1ae0849db5b..81fe0166fd7 100644 --- a/library/core/src/slice/mod.rs +++ b/library/core/src/slice/mod.rs @@ -109,6 +109,7 @@ impl<T> [T] { #[lang = "slice_len_fn"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_slice_len", since = "1.39.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[inline] #[must_use] pub const fn len(&self) -> usize { @@ -128,6 +129,7 @@ impl<T> [T] { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_slice_is_empty", since = "1.39.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[inline] #[must_use] pub const fn is_empty(&self) -> bool { @@ -562,6 +564,7 @@ impl<T> [T] { /// assert_eq!(None, v.get(0..4)); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[inline] #[must_use] pub fn get<I>(&self, index: I) -> Option<&I::Output> @@ -587,6 +590,7 @@ impl<T> [T] { /// assert_eq!(x, &[0, 42, 2]); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[inline] #[must_use] pub fn get_mut<I>(&mut self, index: I) -> Option<&mut I::Output> @@ -624,6 +628,7 @@ impl<T> [T] { /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[inline] #[must_use] pub unsafe fn get_unchecked<I>(&self, index: I) -> &I::Output @@ -666,6 +671,7 @@ impl<T> [T] { /// assert_eq!(x, &[1, 13, 4]); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[inline] #[must_use] pub unsafe fn get_unchecked_mut<I>(&mut self, index: I) -> &mut I::Output @@ -1262,6 +1268,18 @@ impl<T> [T] { /// Splits the slice into a slice of `N`-element arrays, /// assuming that there's no remainder. /// + /// This is the inverse operation to [`as_flattened`]. + /// + /// [`as_flattened`]: slice::as_flattened + /// + /// As this is `unsafe`, consider whether you could use [`as_chunks`] or + /// [`as_rchunks`] instead, perhaps via something like + /// `if let (chunks, []) = slice.as_chunks()` or + /// `let (chunks, []) = slice.as_chunks() else { unreachable!() };`. + /// + /// [`as_chunks`]: slice::as_chunks + /// [`as_rchunks`]: slice::as_rchunks + /// /// # Safety /// /// This may only be called when @@ -1271,7 +1289,6 @@ impl<T> [T] { /// # Examples /// /// ``` - /// #![feature(slice_as_chunks)] /// let slice: &[char] = &['l', 'o', 'r', 'e', 'm', '!']; /// let chunks: &[[char; 1]] = /// // SAFETY: 1-element chunks never have remainder @@ -1286,7 +1303,8 @@ impl<T> [T] { /// // let chunks: &[[_; 5]] = slice.as_chunks_unchecked() // The slice length is not a multiple of 5 /// // let chunks: &[[_; 0]] = slice.as_chunks_unchecked() // Zero-length chunks are never allowed /// ``` - #[unstable(feature = "slice_as_chunks", issue = "74985")] + #[stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] #[inline] #[must_use] pub const unsafe fn as_chunks_unchecked<const N: usize>(&self) -> &[[T; N]] { @@ -1306,15 +1324,27 @@ impl<T> [T] { /// starting at the beginning of the slice, /// and a remainder slice with length strictly less than `N`. /// + /// The remainder is meaningful in the division sense. Given + /// `let (chunks, remainder) = slice.as_chunks()`, then: + /// - `chunks.len()` equals `slice.len() / N`, + /// - `remainder.len()` equals `slice.len() % N`, and + /// - `slice.len()` equals `chunks.len() * N + remainder.len()`. + /// + /// You can flatten the chunks back into a slice-of-`T` with [`as_flattened`]. + /// + /// [`as_flattened`]: slice::as_flattened + /// /// # Panics /// - /// Panics if `N` is zero. This check will most probably get changed to a compile time - /// error before this method gets stabilized. + /// Panics if `N` is zero. + /// + /// Note that this check is against a const generic parameter, not a runtime + /// value, and thus a particular monomorphization will either always panic + /// or it will never panic. /// /// # Examples /// /// ``` - /// #![feature(slice_as_chunks)] /// let slice = ['l', 'o', 'r', 'e', 'm']; /// let (chunks, remainder) = slice.as_chunks(); /// assert_eq!(chunks, &[['l', 'o'], ['r', 'e']]); @@ -1324,14 +1354,14 @@ impl<T> [T] { /// If you expect the slice to be an exact multiple, you can combine /// `let`-`else` with an empty slice pattern: /// ``` - /// #![feature(slice_as_chunks)] /// let slice = ['R', 'u', 's', 't']; /// let (chunks, []) = slice.as_chunks::<2>() else { /// panic!("slice didn't have even length") /// }; /// assert_eq!(chunks, &[['R', 'u'], ['s', 't']]); /// ``` - #[unstable(feature = "slice_as_chunks", issue = "74985")] + #[stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] #[inline] #[track_caller] #[must_use] @@ -1351,21 +1381,34 @@ impl<T> [T] { /// starting at the end of the slice, /// and a remainder slice with length strictly less than `N`. /// + /// The remainder is meaningful in the division sense. Given + /// `let (remainder, chunks) = slice.as_rchunks()`, then: + /// - `remainder.len()` equals `slice.len() % N`, + /// - `chunks.len()` equals `slice.len() / N`, and + /// - `slice.len()` equals `chunks.len() * N + remainder.len()`. + /// + /// You can flatten the chunks back into a slice-of-`T` with [`as_flattened`]. + /// + /// [`as_flattened`]: slice::as_flattened + /// /// # Panics /// - /// Panics if `N` is zero. This check will most probably get changed to a compile time - /// error before this method gets stabilized. + /// Panics if `N` is zero. + /// + /// Note that this check is against a const generic parameter, not a runtime + /// value, and thus a particular monomorphization will either always panic + /// or it will never panic. /// /// # Examples /// /// ``` - /// #![feature(slice_as_chunks)] /// let slice = ['l', 'o', 'r', 'e', 'm']; /// let (remainder, chunks) = slice.as_rchunks(); /// assert_eq!(remainder, &['l']); /// assert_eq!(chunks, &[['o', 'r'], ['e', 'm']]); /// ``` - #[unstable(feature = "slice_as_chunks", issue = "74985")] + #[stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] #[inline] #[track_caller] #[must_use] @@ -1418,6 +1461,18 @@ impl<T> [T] { /// Splits the slice into a slice of `N`-element arrays, /// assuming that there's no remainder. /// + /// This is the inverse operation to [`as_flattened_mut`]. + /// + /// [`as_flattened_mut`]: slice::as_flattened_mut + /// + /// As this is `unsafe`, consider whether you could use [`as_chunks_mut`] or + /// [`as_rchunks_mut`] instead, perhaps via something like + /// `if let (chunks, []) = slice.as_chunks_mut()` or + /// `let (chunks, []) = slice.as_chunks_mut() else { unreachable!() };`. + /// + /// [`as_chunks_mut`]: slice::as_chunks_mut + /// [`as_rchunks_mut`]: slice::as_rchunks_mut + /// /// # Safety /// /// This may only be called when @@ -1427,7 +1482,6 @@ impl<T> [T] { /// # Examples /// /// ``` - /// #![feature(slice_as_chunks)] /// let slice: &mut [char] = &mut ['l', 'o', 'r', 'e', 'm', '!']; /// let chunks: &mut [[char; 1]] = /// // SAFETY: 1-element chunks never have remainder @@ -1444,7 +1498,8 @@ impl<T> [T] { /// // let chunks: &[[_; 5]] = slice.as_chunks_unchecked_mut() // The slice length is not a multiple of 5 /// // let chunks: &[[_; 0]] = slice.as_chunks_unchecked_mut() // Zero-length chunks are never allowed /// ``` - #[unstable(feature = "slice_as_chunks", issue = "74985")] + #[stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] #[inline] #[must_use] pub const unsafe fn as_chunks_unchecked_mut<const N: usize>(&mut self) -> &mut [[T; N]] { @@ -1464,15 +1519,27 @@ impl<T> [T] { /// starting at the beginning of the slice, /// and a remainder slice with length strictly less than `N`. /// + /// The remainder is meaningful in the division sense. Given + /// `let (chunks, remainder) = slice.as_chunks_mut()`, then: + /// - `chunks.len()` equals `slice.len() / N`, + /// - `remainder.len()` equals `slice.len() % N`, and + /// - `slice.len()` equals `chunks.len() * N + remainder.len()`. + /// + /// You can flatten the chunks back into a slice-of-`T` with [`as_flattened_mut`]. + /// + /// [`as_flattened_mut`]: slice::as_flattened_mut + /// /// # Panics /// - /// Panics if `N` is zero. This check will most probably get changed to a compile time - /// error before this method gets stabilized. + /// Panics if `N` is zero. + /// + /// Note that this check is against a const generic parameter, not a runtime + /// value, and thus a particular monomorphization will either always panic + /// or it will never panic. /// /// # Examples /// /// ``` - /// #![feature(slice_as_chunks)] /// let v = &mut [0, 0, 0, 0, 0]; /// let mut count = 1; /// @@ -1484,7 +1551,8 @@ impl<T> [T] { /// } /// assert_eq!(v, &[1, 1, 2, 2, 9]); /// ``` - #[unstable(feature = "slice_as_chunks", issue = "74985")] + #[stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] #[inline] #[track_caller] #[must_use] @@ -1504,15 +1572,27 @@ impl<T> [T] { /// starting at the end of the slice, /// and a remainder slice with length strictly less than `N`. /// + /// The remainder is meaningful in the division sense. Given + /// `let (remainder, chunks) = slice.as_rchunks_mut()`, then: + /// - `remainder.len()` equals `slice.len() % N`, + /// - `chunks.len()` equals `slice.len() / N`, and + /// - `slice.len()` equals `chunks.len() * N + remainder.len()`. + /// + /// You can flatten the chunks back into a slice-of-`T` with [`as_flattened_mut`]. + /// + /// [`as_flattened_mut`]: slice::as_flattened_mut + /// /// # Panics /// - /// Panics if `N` is zero. This check will most probably get changed to a compile time - /// error before this method gets stabilized. + /// Panics if `N` is zero. + /// + /// Note that this check is against a const generic parameter, not a runtime + /// value, and thus a particular monomorphization will either always panic + /// or it will never panic. /// /// # Examples /// /// ``` - /// #![feature(slice_as_chunks)] /// let v = &mut [0, 0, 0, 0, 0]; /// let mut count = 1; /// @@ -1524,7 +1604,8 @@ impl<T> [T] { /// } /// assert_eq!(v, &[9, 1, 1, 2, 2]); /// ``` - #[unstable(feature = "slice_as_chunks", issue = "74985")] + #[stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "slice_as_chunks", since = "CURRENT_RUSTC_VERSION")] #[inline] #[track_caller] #[must_use] @@ -4810,6 +4891,11 @@ impl<T> [MaybeUninit<T>] { impl<T, const N: usize> [[T; N]] { /// Takes a `&[[T; N]]`, and flattens it to a `&[T]`. /// + /// For the opposite operation, see [`as_chunks`] and [`as_rchunks`]. + /// + /// [`as_chunks`]: slice::as_chunks + /// [`as_rchunks`]: slice::as_rchunks + /// /// # Panics /// /// This panics if the length of the resulting slice would overflow a `usize`. @@ -4850,6 +4936,11 @@ impl<T, const N: usize> [[T; N]] { /// Takes a `&mut [[T; N]]`, and flattens it to a `&mut [T]`. /// + /// For the opposite operation, see [`as_chunks_mut`] and [`as_rchunks_mut`]. + /// + /// [`as_chunks_mut`]: slice::as_chunks_mut + /// [`as_rchunks_mut`]: slice::as_rchunks_mut + /// /// # Panics /// /// This panics if the length of the resulting slice would overflow a `usize`. diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs index 818dcc2125f..dafabba645c 100644 --- a/library/core/src/str/mod.rs +++ b/library/core/src/str/mod.rs @@ -134,6 +134,7 @@ impl str { #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_str_len", since = "1.39.0")] #[rustc_diagnostic_item = "str_len"] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[must_use] #[inline] pub const fn len(&self) -> usize { @@ -153,6 +154,7 @@ impl str { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_str_is_empty", since = "1.39.0")] + #[cfg_attr(not(bootstrap), rustc_no_implicit_autorefs)] #[must_use] #[inline] pub const fn is_empty(&self) -> bool { diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs index 9b1b13e7129..84c7f1aafe1 100644 --- a/library/core/src/sync/atomic.rs +++ b/library/core/src/sync/atomic.rs @@ -247,6 +247,100 @@ use crate::cell::UnsafeCell; use crate::hint::spin_loop; use crate::{fmt, intrinsics}; +trait Sealed {} + +/// A marker trait for primitive types which can be modified atomically. +/// +/// This is an implementation detail for <code>[Atomic]\<T></code> which may disappear or be replaced at any time. +/// +/// # Safety +/// +/// Types implementing this trait must be primitives that can be modified atomically. +/// +/// The associated `Self::AtomicInner` type must have the same size and bit validity as `Self`, +/// but may have a higher alignment requirement, so the following `transmute`s are sound: +/// +/// - `&mut Self::AtomicInner` as `&mut Self` +/// - `Self` as `Self::AtomicInner` or the reverse +#[unstable( + feature = "atomic_internals", + reason = "implementation detail which may disappear or be replaced at any time", + issue = "none" +)] +#[expect(private_bounds)] +pub unsafe trait AtomicPrimitive: Sized + Copy + Sealed { + /// Temporary implementation detail. + type AtomicInner: Sized; +} + +macro impl_atomic_primitive( + $Atom:ident $(<$T:ident>)? ($Primitive:ty), + size($size:literal), + align($align:literal) $(,)? +) { + impl $(<$T>)? Sealed for $Primitive {} + + #[unstable( + feature = "atomic_internals", + reason = "implementation detail which may disappear or be replaced at any time", + issue = "none" + )] + #[cfg(target_has_atomic_load_store = $size)] + unsafe impl $(<$T>)? AtomicPrimitive for $Primitive { + type AtomicInner = $Atom $(<$T>)?; + } +} + +impl_atomic_primitive!(AtomicBool(bool), size("8"), align(1)); +impl_atomic_primitive!(AtomicI8(i8), size("8"), align(1)); +impl_atomic_primitive!(AtomicU8(u8), size("8"), align(1)); +impl_atomic_primitive!(AtomicI16(i16), size("16"), align(2)); +impl_atomic_primitive!(AtomicU16(u16), size("16"), align(2)); +impl_atomic_primitive!(AtomicI32(i32), size("32"), align(4)); +impl_atomic_primitive!(AtomicU32(u32), size("32"), align(4)); +impl_atomic_primitive!(AtomicI64(i64), size("64"), align(8)); +impl_atomic_primitive!(AtomicU64(u64), size("64"), align(8)); +impl_atomic_primitive!(AtomicI128(i128), size("128"), align(16)); +impl_atomic_primitive!(AtomicU128(u128), size("128"), align(16)); + +#[cfg(target_pointer_width = "16")] +impl_atomic_primitive!(AtomicIsize(isize), size("ptr"), align(2)); +#[cfg(target_pointer_width = "32")] +impl_atomic_primitive!(AtomicIsize(isize), size("ptr"), align(4)); +#[cfg(target_pointer_width = "64")] +impl_atomic_primitive!(AtomicIsize(isize), size("ptr"), align(8)); + +#[cfg(target_pointer_width = "16")] +impl_atomic_primitive!(AtomicUsize(usize), size("ptr"), align(2)); +#[cfg(target_pointer_width = "32")] +impl_atomic_primitive!(AtomicUsize(usize), size("ptr"), align(4)); +#[cfg(target_pointer_width = "64")] +impl_atomic_primitive!(AtomicUsize(usize), size("ptr"), align(8)); + +#[cfg(target_pointer_width = "16")] +impl_atomic_primitive!(AtomicPtr<T>(*mut T), size("ptr"), align(2)); +#[cfg(target_pointer_width = "32")] +impl_atomic_primitive!(AtomicPtr<T>(*mut T), size("ptr"), align(4)); +#[cfg(target_pointer_width = "64")] +impl_atomic_primitive!(AtomicPtr<T>(*mut T), size("ptr"), align(8)); + +/// A memory location which can be safely modified from multiple threads. +/// +/// This has the same size and bit validity as the underlying type `T`. However, +/// the alignment of this type is always equal to its size, even on targets where +/// `T` has alignment less than its size. +/// +/// For more about the differences between atomic types and non-atomic types as +/// well as information about the portability of this type, please see the +/// [module-level documentation]. +/// +/// **Note:** This type is only available on platforms that support atomic loads +/// and stores of `T`. +/// +/// [module-level documentation]: crate::sync::atomic +#[unstable(feature = "generic_atomic", issue = "130539")] +pub type Atomic<T> = <T as AtomicPrimitive>::AtomicInner; + // Some architectures don't have byte-sized atomics, which results in LLVM // emulating them using a LL/SC loop. However for AtomicBool we can take // advantage of the fact that it only ever contains 0 or 1 and use atomic OR/AND |