diff options
Diffstat (limited to 'library')
32 files changed, 878 insertions, 99 deletions
diff --git a/library/alloc/src/alloc/tests.rs b/library/alloc/src/alloc/tests.rs index b2f0194599b..1a5938fd34c 100644 --- a/library/alloc/src/alloc/tests.rs +++ b/library/alloc/src/alloc/tests.rs @@ -22,7 +22,6 @@ fn allocate_zeroed() { } #[bench] -#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks fn alloc_owned_small(b: &mut Bencher) { b.iter(|| { let _: Box<_> = Box::new(10); diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs index b7e7d5a38a5..66f4c19e0f9 100644 --- a/library/alloc/src/boxed.rs +++ b/library/alloc/src/boxed.rs @@ -158,6 +158,8 @@ use core::hash::{Hash, Hasher}; #[cfg(not(no_global_oom_handling))] use core::iter::FromIterator; use core::iter::{FusedIterator, Iterator}; +#[cfg(not(bootstrap))] +use core::marker::Tuple; use core::marker::{Destruct, Unpin, Unsize}; use core::mem; use core::ops::{ @@ -1979,6 +1981,7 @@ impl<I: ExactSizeIterator + ?Sized, A: Allocator> ExactSizeIterator for Box<I, A #[stable(feature = "fused", since = "1.26.0")] impl<I: FusedIterator + ?Sized, A: Allocator> FusedIterator for Box<I, A> {} +#[cfg(bootstrap)] #[stable(feature = "boxed_closure_impls", since = "1.35.0")] impl<Args, F: FnOnce<Args> + ?Sized, A: Allocator> FnOnce<Args> for Box<F, A> { type Output = <F as FnOnce<Args>>::Output; @@ -1988,6 +1991,17 @@ impl<Args, F: FnOnce<Args> + ?Sized, A: Allocator> FnOnce<Args> for Box<F, A> { } } +#[cfg(not(bootstrap))] +#[stable(feature = "boxed_closure_impls", since = "1.35.0")] +impl<Args: Tuple, F: FnOnce<Args> + ?Sized, A: Allocator> FnOnce<Args> for Box<F, A> { + type Output = <F as FnOnce<Args>>::Output; + + extern "rust-call" fn call_once(self, args: Args) -> Self::Output { + <F as FnOnce<Args>>::call_once(*self, args) + } +} + +#[cfg(bootstrap)] #[stable(feature = "boxed_closure_impls", since = "1.35.0")] impl<Args, F: FnMut<Args> + ?Sized, A: Allocator> FnMut<Args> for Box<F, A> { extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output { @@ -1995,6 +2009,15 @@ impl<Args, F: FnMut<Args> + ?Sized, A: Allocator> FnMut<Args> for Box<F, A> { } } +#[cfg(not(bootstrap))] +#[stable(feature = "boxed_closure_impls", since = "1.35.0")] +impl<Args: Tuple, F: FnMut<Args> + ?Sized, A: Allocator> FnMut<Args> for Box<F, A> { + extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output { + <F as FnMut<Args>>::call_mut(self, args) + } +} + +#[cfg(bootstrap)] #[stable(feature = "boxed_closure_impls", since = "1.35.0")] impl<Args, F: Fn<Args> + ?Sized, A: Allocator> Fn<Args> for Box<F, A> { extern "rust-call" fn call(&self, args: Args) -> Self::Output { @@ -2002,6 +2025,14 @@ impl<Args, F: Fn<Args> + ?Sized, A: Allocator> Fn<Args> for Box<F, A> { } } +#[cfg(not(bootstrap))] +#[stable(feature = "boxed_closure_impls", since = "1.35.0")] +impl<Args: Tuple, F: Fn<Args> + ?Sized, A: Allocator> Fn<Args> for Box<F, A> { + extern "rust-call" fn call(&self, args: Args) -> Self::Output { + <F as Fn<Args>>::call(self, args) + } +} + #[unstable(feature = "coerce_unsized", issue = "27732")] impl<T: ?Sized + Unsize<U>, U: ?Sized, A: Allocator> CoerceUnsized<Box<U, A>> for Box<T, A> {} diff --git a/library/alloc/src/collections/btree/node/tests.rs b/library/alloc/src/collections/btree/node/tests.rs index aadb0dc9c40..64bce0ff8c0 100644 --- a/library/alloc/src/collections/btree/node/tests.rs +++ b/library/alloc/src/collections/btree/node/tests.rs @@ -94,6 +94,7 @@ fn test_partial_eq() { #[test] #[cfg(target_arch = "x86_64")] +#[cfg_attr(miri, ignore)] // We'd like to run Miri with layout randomization fn test_sizes() { assert_eq!(core::mem::size_of::<LeafNode<(), ()>>(), 16); assert_eq!(core::mem::size_of::<LeafNode<i64, i64>>(), 16 + CAPACITY * 2 * 8); diff --git a/library/alloc/src/collections/mod.rs b/library/alloc/src/collections/mod.rs index 161a375736c..3e0b0f73550 100644 --- a/library/alloc/src/collections/mod.rs +++ b/library/alloc/src/collections/mod.rs @@ -139,7 +139,7 @@ impl Display for TryReserveError { " because the computed capacity exceeded the collection's maximum" } TryReserveErrorKind::AllocError { .. } => { - " because the memory allocator returned a error" + " because the memory allocator returned an error" } }; fmt.write_str(reason) diff --git a/library/alloc/src/collections/vec_deque/tests.rs b/library/alloc/src/collections/vec_deque/tests.rs index 1f2daef213c..6e0f83020f9 100644 --- a/library/alloc/src/collections/vec_deque/tests.rs +++ b/library/alloc/src/collections/vec_deque/tests.rs @@ -3,7 +3,6 @@ use core::iter::TrustedLen; use super::*; #[bench] -#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks fn bench_push_back_100(b: &mut test::Bencher) { let mut deq = VecDeque::with_capacity(101); b.iter(|| { @@ -16,7 +15,6 @@ fn bench_push_back_100(b: &mut test::Bencher) { } #[bench] -#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks fn bench_push_front_100(b: &mut test::Bencher) { let mut deq = VecDeque::with_capacity(101); b.iter(|| { @@ -29,12 +27,15 @@ fn bench_push_front_100(b: &mut test::Bencher) { } #[bench] -#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks fn bench_pop_back_100(b: &mut test::Bencher) { - let mut deq = VecDeque::<i32>::with_capacity(101); + let size = 100; + let mut deq = VecDeque::<i32>::with_capacity(size + 1); + // We'll mess with private state to pretend like `deq` is filled. + // Make sure the buffer is initialized so that we don't read uninit memory. + unsafe { deq.ptr().write_bytes(0u8, size + 1) }; b.iter(|| { - deq.head = 100; + deq.head = size; deq.tail = 0; while !deq.is_empty() { test::black_box(deq.pop_back()); @@ -43,9 +44,9 @@ fn bench_pop_back_100(b: &mut test::Bencher) { } #[bench] -#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks fn bench_retain_whole_10000(b: &mut test::Bencher) { - let v = (1..100000).collect::<VecDeque<u32>>(); + let size = if cfg!(miri) { 1000 } else { 100000 }; + let v = (1..size).collect::<VecDeque<u32>>(); b.iter(|| { let mut v = v.clone(); @@ -54,9 +55,9 @@ fn bench_retain_whole_10000(b: &mut test::Bencher) { } #[bench] -#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks fn bench_retain_odd_10000(b: &mut test::Bencher) { - let v = (1..100000).collect::<VecDeque<u32>>(); + let size = if cfg!(miri) { 1000 } else { 100000 }; + let v = (1..size).collect::<VecDeque<u32>>(); b.iter(|| { let mut v = v.clone(); @@ -65,23 +66,26 @@ fn bench_retain_odd_10000(b: &mut test::Bencher) { } #[bench] -#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks fn bench_retain_half_10000(b: &mut test::Bencher) { - let v = (1..100000).collect::<VecDeque<u32>>(); + let size = if cfg!(miri) { 1000 } else { 100000 }; + let v = (1..size).collect::<VecDeque<u32>>(); b.iter(|| { let mut v = v.clone(); - v.retain(|x| *x > 50000) + v.retain(|x| *x > size / 2) }) } #[bench] -#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks fn bench_pop_front_100(b: &mut test::Bencher) { - let mut deq = VecDeque::<i32>::with_capacity(101); + let size = 100; + let mut deq = VecDeque::<i32>::with_capacity(size + 1); + // We'll mess with private state to pretend like `deq` is filled. + // Make sure the buffer is initialized so that we don't read uninit memory. + unsafe { deq.ptr().write_bytes(0u8, size + 1) }; b.iter(|| { - deq.head = 100; + deq.head = size; deq.tail = 0; while !deq.is_empty() { test::black_box(deq.pop_front()); diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs index ce36b116f13..008926666c1 100644 --- a/library/alloc/src/lib.rs +++ b/library/alloc/src/lib.rs @@ -150,6 +150,7 @@ #![feature(trusted_len)] #![feature(trusted_random_access)] #![feature(try_trait_v2)] +#![cfg_attr(not(bootstrap), feature(tuple_trait))] #![feature(unchecked_math)] #![feature(unicode_internals)] #![feature(unsize)] diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs index 834c8f58cb2..766006939fa 100644 --- a/library/alloc/src/vec/mod.rs +++ b/library/alloc/src/vec/mod.rs @@ -2780,7 +2780,7 @@ impl<T, A: Allocator> IntoIterator for Vec<T, A> { /// assert_eq!(v_iter.next(), None); /// ``` #[inline] - fn into_iter(self) -> IntoIter<T, A> { + fn into_iter(self) -> Self::IntoIter { unsafe { let mut me = ManuallyDrop::new(self); let alloc = ManuallyDrop::new(ptr::read(me.allocator())); @@ -2808,7 +2808,7 @@ impl<'a, T, A: Allocator> IntoIterator for &'a Vec<T, A> { type Item = &'a T; type IntoIter = slice::Iter<'a, T>; - fn into_iter(self) -> slice::Iter<'a, T> { + fn into_iter(self) -> Self::IntoIter { self.iter() } } @@ -2818,7 +2818,7 @@ impl<'a, T, A: Allocator> IntoIterator for &'a mut Vec<T, A> { type Item = &'a mut T; type IntoIter = slice::IterMut<'a, T>; - fn into_iter(self) -> slice::IterMut<'a, T> { + fn into_iter(self) -> Self::IntoIter { self.iter_mut() } } diff --git a/library/core/benches/iter.rs b/library/core/benches/iter.rs index 38887f29af1..9193c79bee8 100644 --- a/library/core/benches/iter.rs +++ b/library/core/benches/iter.rs @@ -1,3 +1,4 @@ +use core::borrow::Borrow; use core::iter::*; use core::mem; use core::num::Wrapping; @@ -403,13 +404,31 @@ fn bench_trusted_random_access_adapters(b: &mut Bencher) { /// Exercises the iter::Copied specialization for slice::Iter #[bench] -fn bench_copied_array_chunks(b: &mut Bencher) { +fn bench_copied_chunks(b: &mut Bencher) { + let v = vec![1u8; 1024]; + + b.iter(|| { + let mut iter = black_box(&v).iter().copied(); + let mut acc = Wrapping(0); + // This uses a while-let loop to side-step the TRA specialization in ArrayChunks + while let Ok(chunk) = iter.next_chunk::<{ mem::size_of::<u64>() }>() { + let d = u64::from_ne_bytes(chunk); + acc += Wrapping(d.rotate_left(7).wrapping_add(1)); + } + acc + }) +} + +/// Exercises the TrustedRandomAccess specialization in ArrayChunks +#[bench] +fn bench_trusted_random_access_chunks(b: &mut Bencher) { let v = vec![1u8; 1024]; b.iter(|| { black_box(&v) .iter() - .copied() + // this shows that we're not relying on the slice::Iter specialization in Copied + .map(|b| *b.borrow()) .array_chunks::<{ mem::size_of::<u64>() }>() .map(|ary| { let d = u64::from_ne_bytes(ary); diff --git a/library/core/benches/lib.rs b/library/core/benches/lib.rs index 1e462e3fc3f..f1244d93285 100644 --- a/library/core/benches/lib.rs +++ b/library/core/benches/lib.rs @@ -1,10 +1,10 @@ // wasm32 does not support benches (no time). #![cfg(not(target_arch = "wasm32"))] #![feature(flt2dec)] -#![feature(int_log)] #![feature(test)] #![feature(trusted_random_access)] #![feature(iter_array_chunks)] +#![feature(iter_next_chunk)] extern crate test; diff --git a/library/core/src/array/mod.rs b/library/core/src/array/mod.rs index eae0e1c7618..2090756d7a3 100644 --- a/library/core/src/array/mod.rs +++ b/library/core/src/array/mod.rs @@ -865,24 +865,6 @@ where return Ok(Try::from_output(unsafe { mem::zeroed() })); } - struct Guard<'a, T, const N: usize> { - array_mut: &'a mut [MaybeUninit<T>; N], - initialized: usize, - } - - impl<T, const N: usize> Drop for Guard<'_, T, N> { - fn drop(&mut self) { - debug_assert!(self.initialized <= N); - - // SAFETY: this slice will contain only initialized objects. - unsafe { - crate::ptr::drop_in_place(MaybeUninit::slice_assume_init_mut( - &mut self.array_mut.get_unchecked_mut(..self.initialized), - )); - } - } - } - let mut array = MaybeUninit::uninit_array::<N>(); let mut guard = Guard { array_mut: &mut array, initialized: 0 }; @@ -896,13 +878,11 @@ where ControlFlow::Continue(elem) => elem, }; - // SAFETY: `guard.initialized` starts at 0, is increased by one in the - // loop and the loop is aborted once it reaches N (which is - // `array.len()`). + // SAFETY: `guard.initialized` starts at 0, which means push can be called + // at most N times, which this loop does. unsafe { - guard.array_mut.get_unchecked_mut(guard.initialized).write(item); + guard.push_unchecked(item); } - guard.initialized += 1; } None => { let alive = 0..guard.initialized; @@ -920,6 +900,55 @@ where Ok(Try::from_output(output)) } +/// Panic guard for incremental initialization of arrays. +/// +/// Disarm the guard with `mem::forget` once the array has been initialized. +/// +/// # Safety +/// +/// All write accesses to this structure are unsafe and must maintain a correct +/// count of `initialized` elements. +/// +/// To minimize indirection fields are still pub but callers should at least use +/// `push_unchecked` to signal that something unsafe is going on. +pub(crate) struct Guard<'a, T, const N: usize> { + /// The array to be initialized. + pub array_mut: &'a mut [MaybeUninit<T>; N], + /// The number of items that have been initialized so far. + pub initialized: usize, +} + +impl<T, const N: usize> Guard<'_, T, N> { + /// Adds an item to the array and updates the initialized item counter. + /// + /// # Safety + /// + /// No more than N elements must be initialized. + #[inline] + pub unsafe fn push_unchecked(&mut self, item: T) { + // SAFETY: If `initialized` was correct before and the caller does not + // invoke this method more than N times then writes will be in-bounds + // and slots will not be initialized more than once. + unsafe { + self.array_mut.get_unchecked_mut(self.initialized).write(item); + self.initialized = self.initialized.unchecked_add(1); + } + } +} + +impl<T, const N: usize> Drop for Guard<'_, T, N> { + fn drop(&mut self) { + debug_assert!(self.initialized <= N); + + // SAFETY: this slice will contain only initialized objects. + unsafe { + crate::ptr::drop_in_place(MaybeUninit::slice_assume_init_mut( + &mut self.array_mut.get_unchecked_mut(..self.initialized), + )); + } + } +} + /// Returns the next chunk of `N` items from the iterator or errors with an /// iterator over the remainder. Used for `Iterator::next_chunk`. #[inline] diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs index e6a11218139..f2975d05457 100644 --- a/library/core/src/cell.rs +++ b/library/core/src/cell.rs @@ -1936,7 +1936,7 @@ impl<T> UnsafeCell<T> { /// Constructs a new instance of `UnsafeCell` which will wrap the specified /// value. /// - /// All access to the inner value through methods is `unsafe`. + /// All access to the inner value through `&UnsafeCell<T>` requires `unsafe` code. /// /// # Examples /// diff --git a/library/core/src/const_closure.rs b/library/core/src/const_closure.rs index 9e9c02093be..151c8e6d898 100644 --- a/library/core/src/const_closure.rs +++ b/library/core/src/const_closure.rs @@ -1,4 +1,6 @@ use crate::marker::Destruct; +#[cfg(not(bootstrap))] +use crate::marker::Tuple; /// Struct representing a closure with mutably borrowed data. /// @@ -44,6 +46,7 @@ impl<'a, CapturedData: ?Sized, Function> ConstFnMutClosure<&'a mut CapturedData, macro_rules! impl_fn_mut_tuple { ($($var:ident)*) => { + #[cfg(bootstrap)] #[allow(unused_parens)] impl<'a, $($var,)* ClosureArguments, Function, ClosureReturnValue> const FnOnce<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> @@ -56,6 +59,7 @@ macro_rules! impl_fn_mut_tuple { self.call_mut(args) } } + #[cfg(bootstrap)] #[allow(unused_parens)] impl<'a, $($var,)* ClosureArguments, Function, ClosureReturnValue> const FnMut<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> @@ -68,6 +72,32 @@ macro_rules! impl_fn_mut_tuple { (self.func)(($($var),*), args) } } + #[cfg(not(bootstrap))] + #[allow(unused_parens)] + impl<'a, $($var,)* ClosureArguments: Tuple, Function, ClosureReturnValue> const + FnOnce<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> + where + Function: ~const Fn(($(&mut $var),*), ClosureArguments) -> ClosureReturnValue+ ~const Destruct, + { + type Output = ClosureReturnValue; + + extern "rust-call" fn call_once(mut self, args: ClosureArguments) -> Self::Output { + self.call_mut(args) + } + } + #[cfg(not(bootstrap))] + #[allow(unused_parens)] + impl<'a, $($var,)* ClosureArguments: Tuple, Function, ClosureReturnValue> const + FnMut<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> + where + Function: ~const Fn(($(&mut $var),*), ClosureArguments)-> ClosureReturnValue, + { + extern "rust-call" fn call_mut(&mut self, args: ClosureArguments) -> Self::Output { + #[allow(non_snake_case)] + let ($($var),*) = &mut self.data; + (self.func)(($($var),*), args) + } + } }; } impl_fn_mut_tuple!(A); diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs index 1dc79afe83f..cec603dcb10 100644 --- a/library/core/src/intrinsics.rs +++ b/library/core/src/intrinsics.rs @@ -55,8 +55,13 @@ #![allow(missing_docs)] use crate::marker::DiscriminantKind; +#[cfg(not(bootstrap))] +use crate::marker::Tuple; use crate::mem; +#[cfg(not(bootstrap))] +pub mod mir; + // These imports are used for simplifying intra-doc links #[allow(unused_imports)] #[cfg(all(target_has_atomic = "8", target_has_atomic = "32", target_has_atomic = "ptr"))] @@ -2169,11 +2174,75 @@ extern "rust-intrinsic" { /// `unreachable_unchecked` is actually being reached. The bug is in *crate A*, /// which violates the principle that a `const fn` must behave the same at /// compile-time and at run-time. The unsafe code in crate B is fine. + #[cfg(bootstrap)] #[rustc_const_unstable(feature = "const_eval_select", issue = "none")] pub fn const_eval_select<ARG, F, G, RET>(arg: ARG, called_in_const: F, called_at_rt: G) -> RET where G: FnOnce<ARG, Output = RET>, F: FnOnce<ARG, Output = RET>; + + /// Selects which function to call depending on the context. + /// + /// If this function is evaluated at compile-time, then a call to this + /// intrinsic will be replaced with a call to `called_in_const`. It gets + /// replaced with a call to `called_at_rt` otherwise. + /// + /// # Type Requirements + /// + /// The two functions must be both function items. They cannot be function + /// pointers or closures. The first function must be a `const fn`. + /// + /// `arg` will be the tupled arguments that will be passed to either one of + /// the two functions, therefore, both functions must accept the same type of + /// arguments. Both functions must return RET. + /// + /// # Safety + /// + /// The two functions must behave observably equivalent. Safe code in other + /// crates may assume that calling a `const fn` at compile-time and at run-time + /// produces the same result. A function that produces a different result when + /// evaluated at run-time, or has any other observable side-effects, is + /// *unsound*. + /// + /// Here is an example of how this could cause a problem: + /// ```no_run + /// #![feature(const_eval_select)] + /// #![feature(core_intrinsics)] + /// use std::hint::unreachable_unchecked; + /// use std::intrinsics::const_eval_select; + /// + /// // Crate A + /// pub const fn inconsistent() -> i32 { + /// fn runtime() -> i32 { 1 } + /// const fn compiletime() -> i32 { 2 } + /// + /// unsafe { + // // ⚠ This code violates the required equivalence of `compiletime` + /// // and `runtime`. + /// const_eval_select((), compiletime, runtime) + /// } + /// } + /// + /// // Crate B + /// const X: i32 = inconsistent(); + /// let x = inconsistent(); + /// if x != X { unsafe { unreachable_unchecked(); }} + /// ``` + /// + /// This code causes Undefined Behavior when being run, since the + /// `unreachable_unchecked` is actually being reached. The bug is in *crate A*, + /// which violates the principle that a `const fn` must behave the same at + /// compile-time and at run-time. The unsafe code in crate B is fine. + #[cfg(not(bootstrap))] + #[rustc_const_unstable(feature = "const_eval_select", issue = "none")] + pub fn const_eval_select<ARG: Tuple, F, G, RET>( + arg: ARG, + called_in_const: F, + called_at_rt: G, + ) -> RET + where + G: FnOnce<ARG, Output = RET>, + F: FnOnce<ARG, Output = RET>; } // Some functions are defined here because they accidentally got made diff --git a/library/core/src/intrinsics/mir.rs b/library/core/src/intrinsics/mir.rs new file mode 100644 index 00000000000..1bacdc39148 --- /dev/null +++ b/library/core/src/intrinsics/mir.rs @@ -0,0 +1,123 @@ +//! Rustc internal tooling for hand-writing MIR. +//! +//! If for some reasons you are not writing rustc tests and have found yourself considering using +//! this feature, turn back. This is *exceptionally* unstable. There is no attempt at all to make +//! anything work besides those things which the rustc test suite happened to need. If you make a +//! typo you'll probably ICE. Really, this is not the solution to your problems. Consider instead +//! supporting the [stable MIR project group](https://github.com/rust-lang/project-stable-mir). +//! +//! The documentation for this module describes how to use this feature. If you are interested in +//! hacking on the implementation, most of that documentation lives at +//! `rustc_mir_building/src/build/custom/mod.rs`. +//! +//! Typical usage will look like this: +//! +//! ```rust +//! #![feature(core_intrinsics, custom_mir)] +//! +//! extern crate core; +//! use core::intrinsics::mir::*; +//! +//! #[custom_mir(dialect = "built")] +//! pub fn simple(x: i32) -> i32 { +//! mir!( +//! let temp1: i32; +//! let temp2: _; +//! +//! { +//! temp1 = x; +//! Goto(exit) +//! } +//! +//! exit = { +//! temp2 = Move(temp1); +//! RET = temp2; +//! Return() +//! } +//! ) +//! } +//! ``` +//! +//! Hopefully most of this is fairly self-explanatory. Expanding on some notable details: +//! +//! - The `custom_mir` attribute tells the compiler to treat the function as being custom MIR. This +//! attribute only works on functions - there is no way to insert custom MIR into the middle of +//! another function. +//! - The `dialect` and `phase` parameters indicate which version of MIR you are inserting here. +//! This will normally be the phase that corresponds to the thing you are trying to test. The +//! phase can be omitted for dialects that have just one. +//! - You should define your function signature like you normally would. Externally, this function +//! can be called like any other function. +//! - Type inference works - you don't have to spell out the type of all of your locals. +//! +//! For now, all statements and terminators are parsed from nested invocations of the special +//! functions provided in this module. We additionally want to (but do not yet) support more +//! "normal" Rust syntax in places where it makes sense. Also, most kinds of instructions are not +//! supported yet. +//! + +#![unstable( + feature = "custom_mir", + reason = "MIR is an implementation detail and extremely unstable", + issue = "none" +)] +#![allow(unused_variables, non_snake_case, missing_debug_implementations)] + +/// Type representing basic blocks. +/// +/// All terminators will have this type as a return type. It helps achieve some type safety. +pub struct BasicBlock; + +macro_rules! define { + ($name:literal, $($sig:tt)*) => { + #[rustc_diagnostic_item = $name] + pub $($sig)* { panic!() } + } +} + +define!("mir_return", fn Return() -> BasicBlock); +define!("mir_goto", fn Goto(destination: BasicBlock) -> BasicBlock); +define!("mir_retag", fn Retag<T>(place: T)); +define!("mir_retag_raw", fn RetagRaw<T>(place: T)); +define!("mir_move", fn Move<T>(place: T) -> T); + +/// Convenience macro for generating custom MIR. +/// +/// See the module documentation for syntax details. This macro is not magic - it only transforms +/// your MIR into something that is easier to parse in the compiler. +#[rustc_macro_transparency = "transparent"] +pub macro mir { + ( + $(let $local_decl:ident $(: $local_decl_ty:ty)? ;)* + + $entry_block:block + + $( + $block_name:ident = $block:block + )* + ) => {{ + // First, we declare all basic blocks. + $( + let $block_name: ::core::intrinsics::mir::BasicBlock; + )* + + { + // Now all locals + #[allow(non_snake_case)] + let RET; + $( + let $local_decl $(: $local_decl_ty)? ; + )* + + { + // Finally, the contents of the basic blocks + $entry_block; + $( + $block; + )* + + RET + } + } + }} +} diff --git a/library/core/src/iter/adapters/array_chunks.rs b/library/core/src/iter/adapters/array_chunks.rs index d4fb886101f..5e4211058aa 100644 --- a/library/core/src/iter/adapters/array_chunks.rs +++ b/library/core/src/iter/adapters/array_chunks.rs @@ -1,6 +1,8 @@ use crate::array; -use crate::iter::{ByRefSized, FusedIterator, Iterator}; -use crate::ops::{ControlFlow, Try}; +use crate::const_closure::ConstFnMutClosure; +use crate::iter::{ByRefSized, FusedIterator, Iterator, TrustedRandomAccessNoCoerce}; +use crate::mem::{self, MaybeUninit}; +use crate::ops::{ControlFlow, NeverShortCircuit, Try}; /// An iterator over `N` elements of the iterator at a time. /// @@ -82,7 +84,13 @@ where } } - impl_fold_via_try_fold! { fold -> try_fold } + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + <Self as SpecFold>::fold(self, init, f) + } } #[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] @@ -168,3 +176,64 @@ where self.iter.len() < N } } + +trait SpecFold: Iterator { + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B; +} + +impl<I, const N: usize> SpecFold for ArrayChunks<I, N> +where + I: Iterator, +{ + #[inline] + default fn fold<B, F>(mut self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + let fold = ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp); + self.try_fold(init, fold).0 + } +} + +impl<I, const N: usize> SpecFold for ArrayChunks<I, N> +where + I: Iterator + TrustedRandomAccessNoCoerce, +{ + #[inline] + fn fold<B, F>(mut self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + let mut accum = init; + let inner_len = self.iter.size(); + let mut i = 0; + // Use a while loop because (0..len).step_by(N) doesn't optimize well. + while inner_len - i >= N { + let mut chunk = MaybeUninit::uninit_array(); + let mut guard = array::Guard { array_mut: &mut chunk, initialized: 0 }; + while guard.initialized < N { + // SAFETY: The method consumes the iterator and the loop condition ensures that + // all accesses are in bounds and only happen once. + unsafe { + let idx = i + guard.initialized; + guard.push_unchecked(self.iter.__iterator_get_unchecked(idx)); + } + } + mem::forget(guard); + // SAFETY: The loop above initialized all elements + let chunk = unsafe { MaybeUninit::array_assume_init(chunk) }; + accum = f(accum, chunk); + i += N; + } + + // unlike try_fold this method does not need to take care of the remainder + // since `self` will be dropped + + accum + } +} diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs index 81f050cb283..404ddff4f9d 100644 --- a/library/core/src/num/int_macros.rs +++ b/library/core/src/num/int_macros.rs @@ -2271,15 +2271,16 @@ macro_rules! int_impl { /// # Panics /// /// This function will panic if `self` is less than or equal to zero, - /// or if `base` is less then 2. + /// or if `base` is less than 2. /// /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_allow_const_fn_unstable(const_option)] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -2298,10 +2299,11 @@ macro_rules! int_impl { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_allow_const_fn_unstable(const_option)] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -2319,10 +2321,11 @@ macro_rules! int_impl { /// # Example /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_allow_const_fn_unstable(const_option)] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -2343,10 +2346,10 @@ macro_rules! int_impl { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -2379,10 +2382,10 @@ macro_rules! int_impl { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -2403,10 +2406,10 @@ macro_rules! int_impl { /// # Example /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs index 6b6f3417f8a..5b7521220ac 100644 --- a/library/core/src/num/nonzero.rs +++ b/library/core/src/num/nonzero.rs @@ -460,14 +460,14 @@ macro_rules! nonzero_unsigned_operations { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("# use std::num::", stringify!($Ty), ";")] /// #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(7).unwrap().ilog2(), 2);")] #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(8).unwrap().ilog2(), 3);")] #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(9).unwrap().ilog2(), 3);")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -485,14 +485,14 @@ macro_rules! nonzero_unsigned_operations { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("# use std::num::", stringify!($Ty), ";")] /// #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(99).unwrap().ilog10(), 1);")] #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(100).unwrap().ilog10(), 2);")] #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(101).unwrap().ilog10(), 2);")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs index 93f65c5c7aa..0563f28278d 100644 --- a/library/core/src/num/uint_macros.rs +++ b/library/core/src/num/uint_macros.rs @@ -692,15 +692,16 @@ macro_rules! uint_impl { /// /// # Panics /// - /// This function will panic if `self` is zero, or if `base` is less then 2. + /// This function will panic if `self` is zero, or if `base` is less than 2. /// /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_allow_const_fn_unstable(const_option)] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -719,10 +720,11 @@ macro_rules! uint_impl { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_allow_const_fn_unstable(const_option)] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -740,10 +742,11 @@ macro_rules! uint_impl { /// # Example /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_allow_const_fn_unstable(const_option)] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -764,10 +767,10 @@ macro_rules! uint_impl { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -800,10 +803,10 @@ macro_rules! uint_impl { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -822,10 +825,10 @@ macro_rules! uint_impl { /// # Examples /// /// ``` - /// #![feature(int_log)] #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")] /// ``` - #[unstable(feature = "int_log", issue = "70887")] + #[stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "int_log", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] diff --git a/library/core/src/ops/function.rs b/library/core/src/ops/function.rs index 2e0a752c815..11b43b621c7 100644 --- a/library/core/src/ops/function.rs +++ b/library/core/src/ops/function.rs @@ -1,3 +1,6 @@ +#[cfg(not(bootstrap))] +use crate::marker::Tuple; + /// The version of the call operator that takes an immutable receiver. /// /// Instances of `Fn` can be called repeatedly without mutating state. @@ -51,6 +54,7 @@ /// let double = |x| x * 2; /// assert_eq!(call_with_one(double), 2); /// ``` +#[cfg(bootstrap)] #[lang = "fn"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "Fn"] @@ -71,13 +75,93 @@ )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] -#[cfg_attr(not(bootstrap), const_trait)] pub trait Fn<Args>: FnMut<Args> { /// Performs the call operation. #[unstable(feature = "fn_traits", issue = "29625")] extern "rust-call" fn call(&self, args: Args) -> Self::Output; } +/// The version of the call operator that takes an immutable receiver. +/// +/// Instances of `Fn` can be called repeatedly without mutating state. +/// +/// *This trait (`Fn`) is not to be confused with [function pointers] +/// (`fn`).* +/// +/// `Fn` is implemented automatically by closures which only take immutable +/// references to captured variables or don't capture anything at all, as well +/// as (safe) [function pointers] (with some caveats, see their documentation +/// for more details). Additionally, for any type `F` that implements `Fn`, `&F` +/// implements `Fn`, too. +/// +/// Since both [`FnMut`] and [`FnOnce`] are supertraits of `Fn`, any +/// instance of `Fn` can be used as a parameter where a [`FnMut`] or [`FnOnce`] +/// is expected. +/// +/// Use `Fn` as a bound when you want to accept a parameter of function-like +/// type and need to call it repeatedly and without mutating state (e.g., when +/// calling it concurrently). If you do not need such strict requirements, use +/// [`FnMut`] or [`FnOnce`] as bounds. +/// +/// See the [chapter on closures in *The Rust Programming Language*][book] for +/// some more information on this topic. +/// +/// Also of note is the special syntax for `Fn` traits (e.g. +/// `Fn(usize, bool) -> usize`). Those interested in the technical details of +/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. +/// +/// [book]: ../../book/ch13-01-closures.html +/// [function pointers]: fn +/// [nomicon]: ../../nomicon/hrtb.html +/// +/// # Examples +/// +/// ## Calling a closure +/// +/// ``` +/// let square = |x| x * x; +/// assert_eq!(square(5), 25); +/// ``` +/// +/// ## Using a `Fn` parameter +/// +/// ``` +/// fn call_with_one<F>(func: F) -> usize +/// where F: Fn(usize) -> usize { +/// func(1) +/// } +/// +/// let double = |x| x * 2; +/// assert_eq!(call_with_one(double), 2); +/// ``` +#[cfg(not(bootstrap))] +#[lang = "fn"] +#[stable(feature = "rust1", since = "1.0.0")] +#[rustc_diagnostic_item = "Fn"] +#[rustc_paren_sugar] +#[rustc_on_unimplemented( + on( + Args = "()", + note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" + ), + on( + _Self = "unsafe fn", + note = "unsafe function cannot be called generically without an unsafe block", + // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string + label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" + ), + message = "expected a `{Fn}<{Args}>` closure, found `{Self}`", + label = "expected an `Fn<{Args}>` closure, found `{Self}`" +)] +#[fundamental] // so that regex can rely that `&str: !FnMut` +#[must_use = "closures are lazy and do nothing unless called"] +#[const_trait] +pub trait Fn<Args: Tuple>: FnMut<Args> { + /// Performs the call operation. + #[unstable(feature = "fn_traits", issue = "29625")] + extern "rust-call" fn call(&self, args: Args) -> Self::Output; +} + /// The version of the call operator that takes a mutable receiver. /// /// Instances of `FnMut` can be called repeatedly and may mutate state. @@ -139,6 +223,7 @@ pub trait Fn<Args>: FnMut<Args> { /// /// assert_eq!(x, 5); /// ``` +#[cfg(bootstrap)] #[lang = "fn_mut"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "FnMut"] @@ -159,13 +244,101 @@ pub trait Fn<Args>: FnMut<Args> { )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] -#[cfg_attr(not(bootstrap), const_trait)] pub trait FnMut<Args>: FnOnce<Args> { /// Performs the call operation. #[unstable(feature = "fn_traits", issue = "29625")] extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output; } +/// The version of the call operator that takes a mutable receiver. +/// +/// Instances of `FnMut` can be called repeatedly and may mutate state. +/// +/// `FnMut` is implemented automatically by closures which take mutable +/// references to captured variables, as well as all types that implement +/// [`Fn`], e.g., (safe) [function pointers] (since `FnMut` is a supertrait of +/// [`Fn`]). Additionally, for any type `F` that implements `FnMut`, `&mut F` +/// implements `FnMut`, too. +/// +/// Since [`FnOnce`] is a supertrait of `FnMut`, any instance of `FnMut` can be +/// used where a [`FnOnce`] is expected, and since [`Fn`] is a subtrait of +/// `FnMut`, any instance of [`Fn`] can be used where `FnMut` is expected. +/// +/// Use `FnMut` as a bound when you want to accept a parameter of function-like +/// type and need to call it repeatedly, while allowing it to mutate state. +/// If you don't want the parameter to mutate state, use [`Fn`] as a +/// bound; if you don't need to call it repeatedly, use [`FnOnce`]. +/// +/// See the [chapter on closures in *The Rust Programming Language*][book] for +/// some more information on this topic. +/// +/// Also of note is the special syntax for `Fn` traits (e.g. +/// `Fn(usize, bool) -> usize`). Those interested in the technical details of +/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. +/// +/// [book]: ../../book/ch13-01-closures.html +/// [function pointers]: fn +/// [nomicon]: ../../nomicon/hrtb.html +/// +/// # Examples +/// +/// ## Calling a mutably capturing closure +/// +/// ``` +/// let mut x = 5; +/// { +/// let mut square_x = || x *= x; +/// square_x(); +/// } +/// assert_eq!(x, 25); +/// ``` +/// +/// ## Using a `FnMut` parameter +/// +/// ``` +/// fn do_twice<F>(mut func: F) +/// where F: FnMut() +/// { +/// func(); +/// func(); +/// } +/// +/// let mut x: usize = 1; +/// { +/// let add_two_to_x = || x += 2; +/// do_twice(add_two_to_x); +/// } +/// +/// assert_eq!(x, 5); +/// ``` +#[cfg(not(bootstrap))] +#[lang = "fn_mut"] +#[stable(feature = "rust1", since = "1.0.0")] +#[rustc_diagnostic_item = "FnMut"] +#[rustc_paren_sugar] +#[rustc_on_unimplemented( + on( + Args = "()", + note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" + ), + on( + _Self = "unsafe fn", + note = "unsafe function cannot be called generically without an unsafe block", + // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string + label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" + ), + message = "expected a `{FnMut}<{Args}>` closure, found `{Self}`", + label = "expected an `FnMut<{Args}>` closure, found `{Self}`" +)] +#[fundamental] // so that regex can rely that `&str: !FnMut` +#[must_use = "closures are lazy and do nothing unless called"] +#[const_trait] +pub trait FnMut<Args: Tuple>: FnOnce<Args> { + /// Performs the call operation. + #[unstable(feature = "fn_traits", issue = "29625")] + extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output; +} + /// The version of the call operator that takes a by-value receiver. /// /// Instances of `FnOnce` can be called, but might not be callable multiple @@ -219,6 +392,7 @@ pub trait FnMut<Args>: FnOnce<Args> { /// /// // `consume_and_return_x` can no longer be invoked at this point /// ``` +#[cfg(bootstrap)] #[lang = "fn_once"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "FnOnce"] @@ -239,7 +413,6 @@ pub trait FnMut<Args>: FnOnce<Args> { )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] -#[cfg_attr(not(bootstrap), const_trait)] pub trait FnOnce<Args> { /// The returned type after the call operator is used. #[lang = "fn_once_output"] @@ -251,6 +424,93 @@ pub trait FnOnce<Args> { extern "rust-call" fn call_once(self, args: Args) -> Self::Output; } +/// The version of the call operator that takes a by-value receiver. +/// +/// Instances of `FnOnce` can be called, but might not be callable multiple +/// times. Because of this, if the only thing known about a type is that it +/// implements `FnOnce`, it can only be called once. +/// +/// `FnOnce` is implemented automatically by closures that might consume captured +/// variables, as well as all types that implement [`FnMut`], e.g., (safe) +/// [function pointers] (since `FnOnce` is a supertrait of [`FnMut`]). +/// +/// Since both [`Fn`] and [`FnMut`] are subtraits of `FnOnce`, any instance of +/// [`Fn`] or [`FnMut`] can be used where a `FnOnce` is expected. +/// +/// Use `FnOnce` as a bound when you want to accept a parameter of function-like +/// type and only need to call it once. If you need to call the parameter +/// repeatedly, use [`FnMut`] as a bound; if you also need it to not mutate +/// state, use [`Fn`]. +/// +/// See the [chapter on closures in *The Rust Programming Language*][book] for +/// some more information on this topic. +/// +/// Also of note is the special syntax for `Fn` traits (e.g. +/// `Fn(usize, bool) -> usize`). Those interested in the technical details of +/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. +/// +/// [book]: ../../book/ch13-01-closures.html +/// [function pointers]: fn +/// [nomicon]: ../../nomicon/hrtb.html +/// +/// # Examples +/// +/// ## Using a `FnOnce` parameter +/// +/// ``` +/// fn consume_with_relish<F>(func: F) +/// where F: FnOnce() -> String +/// { +/// // `func` consumes its captured variables, so it cannot be run more +/// // than once. +/// println!("Consumed: {}", func()); +/// +/// println!("Delicious!"); +/// +/// // Attempting to invoke `func()` again will throw a `use of moved +/// // value` error for `func`. +/// } +/// +/// let x = String::from("x"); +/// let consume_and_return_x = move || x; +/// consume_with_relish(consume_and_return_x); +/// +/// // `consume_and_return_x` can no longer be invoked at this point +/// ``` +#[cfg(not(bootstrap))] +#[lang = "fn_once"] +#[stable(feature = "rust1", since = "1.0.0")] +#[rustc_diagnostic_item = "FnOnce"] +#[rustc_paren_sugar] +#[rustc_on_unimplemented( + on( + Args = "()", + note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" + ), + on( + _Self = "unsafe fn", + note = "unsafe function cannot be called generically without an unsafe block", + // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string + label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" + ), + message = "expected a `{FnOnce}<{Args}>` closure, found `{Self}`", + label = "expected an `FnOnce<{Args}>` closure, found `{Self}`" +)] +#[fundamental] // so that regex can rely that `&str: !FnMut` +#[must_use = "closures are lazy and do nothing unless called"] +#[const_trait] +pub trait FnOnce<Args: Tuple> { + /// The returned type after the call operator is used. + #[lang = "fn_once_output"] + #[stable(feature = "fn_once_output", since = "1.12.0")] + type Output; + + /// Performs the call operation. + #[unstable(feature = "fn_traits", issue = "29625")] + extern "rust-call" fn call_once(self, args: Args) -> Self::Output; +} + +#[cfg(bootstrap)] mod impls { #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] @@ -310,3 +570,66 @@ mod impls { } } } + +#[cfg(not(bootstrap))] +mod impls { + use crate::marker::Tuple; + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A: Tuple, F: ?Sized> const Fn<A> for &F + where + F: ~const Fn<A>, + { + extern "rust-call" fn call(&self, args: A) -> F::Output { + (**self).call(args) + } + } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A: Tuple, F: ?Sized> const FnMut<A> for &F + where + F: ~const Fn<A>, + { + extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output { + (**self).call(args) + } + } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A: Tuple, F: ?Sized> const FnOnce<A> for &F + where + F: ~const Fn<A>, + { + type Output = F::Output; + + extern "rust-call" fn call_once(self, args: A) -> F::Output { + (*self).call(args) + } + } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A: Tuple, F: ?Sized> const FnMut<A> for &mut F + where + F: ~const FnMut<A>, + { + extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output { + (*self).call_mut(args) + } + } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A: Tuple, F: ?Sized> const FnOnce<A> for &mut F + where + F: ~const FnMut<A>, + { + type Output = F::Output; + extern "rust-call" fn call_once(self, args: A) -> F::Output { + (*self).call_mut(args) + } + } +} diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs index ccef35b4532..f0258640e2a 100644 --- a/library/core/src/pin.rs +++ b/library/core/src/pin.rs @@ -1059,7 +1059,7 @@ impl<P, U> DispatchFromDyn<Pin<U>> for Pin<P> where P: DispatchFromDyn<U> {} /// 8 | let x: Pin<&mut Foo> = { /// | - borrow later stored here /// 9 | let x: Pin<&mut Foo> = pin!(Foo { /* … */ }); -/// | ^^^^^^^^^^^^^^^^^^^^^ creates a temporary which is freed while still in use +/// | ^^^^^^^^^^^^^^^^^^^^^ creates a temporary value which is freed while still in use /// 10 | x /// 11 | }; // <- Foo is dropped /// | - temporary value is freed at the end of this statement diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs index 5a083227bb0..926d2ae5113 100644 --- a/library/core/src/ptr/const_ptr.rs +++ b/library/core/src/ptr/const_ptr.rs @@ -568,6 +568,31 @@ impl<T: ?Sized> *const T { /// /// For non-`Sized` pointees this operation changes only the data pointer, /// leaving the metadata untouched. + /// + /// ## Examples + /// + /// ``` + /// #![feature(ptr_mask, strict_provenance)] + /// let v = 17_u32; + /// let ptr: *const u32 = &v; + /// + /// // `u32` is 4 bytes aligned, + /// // which means that lower 2 bits are always 0. + /// let tag_mask = 0b11; + /// let ptr_mask = !tag_mask; + /// + /// // We can store something in these lower bits + /// let tagged_ptr = ptr.map_addr(|a| a | 0b10); + /// + /// // Get the "tag" back + /// let tag = tagged_ptr.addr() & tag_mask; + /// assert_eq!(tag, 0b10); + /// + /// // Note that `tagged_ptr` is unaligned, it's UB to read from it. + /// // To get original pointer `mask` can be used: + /// let masked_ptr = tagged_ptr.mask(ptr_mask); + /// assert_eq!(unsafe { *masked_ptr }, 17); + /// ``` #[unstable(feature = "ptr_mask", issue = "98290")] #[must_use = "returns a new pointer rather than modifying its argument"] #[inline(always)] diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs index 6764002bcd4..f71696e9ca0 100644 --- a/library/core/src/ptr/mut_ptr.rs +++ b/library/core/src/ptr/mut_ptr.rs @@ -588,6 +588,34 @@ impl<T: ?Sized> *mut T { /// /// For non-`Sized` pointees this operation changes only the data pointer, /// leaving the metadata untouched. + /// + /// ## Examples + /// + /// ``` + /// #![feature(ptr_mask, strict_provenance)] + /// let mut v = 17_u32; + /// let ptr: *mut u32 = &mut v; + /// + /// // `u32` is 4 bytes aligned, + /// // which means that lower 2 bits are always 0. + /// let tag_mask = 0b11; + /// let ptr_mask = !tag_mask; + /// + /// // We can store something in these lower bits + /// let tagged_ptr = ptr.map_addr(|a| a | 0b10); + /// + /// // Get the "tag" back + /// let tag = tagged_ptr.addr() & tag_mask; + /// assert_eq!(tag, 0b10); + /// + /// // Note that `tagged_ptr` is unaligned, it's UB to read from/write to it. + /// // To get original pointer `mask` can be used: + /// let masked_ptr = tagged_ptr.mask(ptr_mask); + /// assert_eq!(unsafe { *masked_ptr }, 17); + /// + /// unsafe { *masked_ptr = 0 }; + /// assert_eq!(v, 0); + /// ``` #[unstable(feature = "ptr_mask", issue = "98290")] #[must_use = "returns a new pointer rather than modifying its argument"] #[inline(always)] diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs index 4f1bb17344b..0f58bc643d9 100644 --- a/library/core/src/slice/mod.rs +++ b/library/core/src/slice/mod.rs @@ -3524,8 +3524,8 @@ impl<T> [T] { } } - /// Transmute the slice to a slice of another type, ensuring alignment of the types is - /// maintained. + /// Transmute the mutable slice to a mutable slice of another type, ensuring alignment of the + /// types is maintained. /// /// This method splits the slice into three distinct slices: prefix, correctly aligned middle /// slice of a new type, and the suffix slice. The method may make the middle slice the greatest @@ -3667,7 +3667,8 @@ impl<T> [T] { unsafe { self.align_to() } } - /// Split a slice into a prefix, a middle of aligned SIMD types, and a suffix. + /// Split a mutable slice into a mutable prefix, a middle of aligned SIMD types, + /// and a mutable suffix. /// /// This is a safe wrapper around [`slice::align_to_mut`], so has the same weak /// postconditions as that method. You're only assured that diff --git a/library/core/src/tuple.rs b/library/core/src/tuple.rs index fc91fe468cc..28275798f75 100644 --- a/library/core/src/tuple.rs +++ b/library/core/src/tuple.rs @@ -22,7 +22,8 @@ macro_rules! tuple_impls { maybe_tuple_doc! { $($T)+ @ #[stable(feature = "rust1", since = "1.0.0")] - impl<$($T:PartialEq),+> PartialEq for ($($T,)+) + #[rustc_const_unstable(feature = "const_cmp", issue = "92391")] + impl<$($T: ~const PartialEq),+> const PartialEq for ($($T,)+) where last_type!($($T,)+): ?Sized { @@ -40,7 +41,7 @@ macro_rules! tuple_impls { maybe_tuple_doc! { $($T)+ @ #[stable(feature = "rust1", since = "1.0.0")] - impl<$($T:Eq),+> Eq for ($($T,)+) + impl<$($T: Eq),+> Eq for ($($T,)+) where last_type!($($T,)+): ?Sized {} @@ -49,7 +50,8 @@ macro_rules! tuple_impls { maybe_tuple_doc! { $($T)+ @ #[stable(feature = "rust1", since = "1.0.0")] - impl<$($T:PartialOrd + PartialEq),+> PartialOrd for ($($T,)+) + #[rustc_const_unstable(feature = "const_cmp", issue = "92391")] + impl<$($T: ~const PartialOrd + ~const PartialEq),+> const PartialOrd for ($($T,)+) where last_type!($($T,)+): ?Sized { @@ -79,7 +81,8 @@ macro_rules! tuple_impls { maybe_tuple_doc! { $($T)+ @ #[stable(feature = "rust1", since = "1.0.0")] - impl<$($T:Ord),+> Ord for ($($T,)+) + #[rustc_const_unstable(feature = "const_cmp", issue = "92391")] + impl<$($T: ~const Ord),+> const Ord for ($($T,)+) where last_type!($($T,)+): ?Sized { diff --git a/library/core/tests/iter/adapters/array_chunks.rs b/library/core/tests/iter/adapters/array_chunks.rs index 4e9d89e1e58..ef4a7e53bdd 100644 --- a/library/core/tests/iter/adapters/array_chunks.rs +++ b/library/core/tests/iter/adapters/array_chunks.rs @@ -139,7 +139,8 @@ fn test_iterator_array_chunks_fold() { let result = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>().fold(0, |acc, _item| acc + 1); assert_eq!(result, 3); - assert_eq!(count.get(), 10); + // fold impls may or may not process the remainder + assert!(count.get() <= 10 && count.get() >= 9); } #[test] diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs index eda176d9fcb..a7db2a02bd7 100644 --- a/library/core/tests/lib.rs +++ b/library/core/tests/lib.rs @@ -64,7 +64,6 @@ #![feature(try_trait_v2)] #![feature(slice_internals)] #![feature(slice_partition_dedup)] -#![feature(int_log)] #![feature(iter_advance_by)] #![feature(iter_array_chunks)] #![feature(iter_collect_into)] diff --git a/library/std/Cargo.toml b/library/std/Cargo.toml index bc10b12ec2a..daa6976c301 100644 --- a/library/std/Cargo.toml +++ b/library/std/Cargo.toml @@ -23,11 +23,11 @@ hashbrown = { version = "0.12", default-features = false, features = ['rustc-dep std_detect = { path = "../stdarch/crates/std_detect", default-features = false, features = ['rustc-dep-of-std'] } # Dependencies of the `backtrace` crate -addr2line = { version = "0.16.0", optional = true, default-features = false } +addr2line = { version = "0.17.0", optional = true, default-features = false } rustc-demangle = { version = "0.1.21", features = ['rustc-dep-of-std'] } -miniz_oxide = { version = "0.4.0", optional = true, default-features = false } +miniz_oxide = { version = "0.5.0", optional = true, default-features = false } [dependencies.object] -version = "0.26.1" +version = "0.29.0" optional = true default-features = false features = ['read_core', 'elf', 'macho', 'pe', 'unaligned', 'archive'] diff --git a/library/std/src/f32.rs b/library/std/src/f32.rs index dafcd876744..4127c4056f2 100644 --- a/library/std/src/f32.rs +++ b/library/std/src/f32.rs @@ -77,9 +77,11 @@ impl f32 { /// ``` /// let f = 3.3_f32; /// let g = -3.3_f32; + /// let h = -3.7_f32; /// /// assert_eq!(f.round(), 3.0); /// assert_eq!(g.round(), -3.0); + /// assert_eq!(h.round(), -4.0); /// ``` #[rustc_allow_incoherent_impl] #[must_use = "method returns a new number and does not mutate the original value"] diff --git a/library/std/src/f64.rs b/library/std/src/f64.rs index 77048f9a28f..cc64258da60 100644 --- a/library/std/src/f64.rs +++ b/library/std/src/f64.rs @@ -77,9 +77,11 @@ impl f64 { /// ``` /// let f = 3.3_f64; /// let g = -3.3_f64; + /// let h = -3.7_f64; /// /// assert_eq!(f.round(), 3.0); /// assert_eq!(g.round(), -3.0); + /// assert_eq!(h.round(), -4.0); /// ``` #[rustc_allow_incoherent_impl] #[must_use = "method returns a new number and does not mutate the original value"] diff --git a/library/std/src/sync/mpsc/mpsc_queue.rs b/library/std/src/sync/mpsc/mpsc_queue.rs index cdd64a5def5..7322512e3b4 100644 --- a/library/std/src/sync/mpsc/mpsc_queue.rs +++ b/library/std/src/sync/mpsc/mpsc_queue.rs @@ -8,8 +8,15 @@ //! method, and see the method for more information about it. Due to this //! caveat, this queue might not be appropriate for all use-cases. -// https://www.1024cores.net/home/lock-free-algorithms -// /queues/non-intrusive-mpsc-node-based-queue +// The original implementation is based off: +// https://www.1024cores.net/home/lock-free-algorithms/queues/non-intrusive-mpsc-node-based-queue +// +// Note that back when the code was imported, it was licensed under the BSD-2-Clause license: +// http://web.archive.org/web/20110411011612/https://www.1024cores.net/home/lock-free-algorithms/queues/unbounded-spsc-queue +// +// The original author of the code agreed to relicense it under `MIT OR Apache-2.0` in 2017, so as +// of today the license of this file is the same as the rest of the codebase: +// https://github.com/rust-lang/rust/pull/42149 #[cfg(all(test, not(target_os = "emscripten")))] mod tests; diff --git a/library/std/src/sync/mpsc/spsc_queue.rs b/library/std/src/sync/mpsc/spsc_queue.rs index 7e745eb31de..61f91313ea9 100644 --- a/library/std/src/sync/mpsc/spsc_queue.rs +++ b/library/std/src/sync/mpsc/spsc_queue.rs @@ -4,7 +4,15 @@ //! concurrently between two threads. This data structure is safe to use and //! enforces the semantics that there is one pusher and one popper. +// The original implementation is based off: // https://www.1024cores.net/home/lock-free-algorithms/queues/unbounded-spsc-queue +// +// Note that back when the code was imported, it was licensed under the BSD-2-Clause license: +// http://web.archive.org/web/20110411011612/https://www.1024cores.net/home/lock-free-algorithms/queues/unbounded-spsc-queue +// +// The original author of the code agreed to relicense it under `MIT OR Apache-2.0` in 2017, so as +// of today the license of this file is the same as the rest of the codebase: +// https://github.com/rust-lang/rust/pull/42149 #[cfg(all(test, not(target_os = "emscripten")))] mod tests; diff --git a/library/unwind/src/lib.rs b/library/unwind/src/lib.rs index 46fe50cb945..32c0ef3e116 100644 --- a/library/unwind/src/lib.rs +++ b/library/unwind/src/lib.rs @@ -15,7 +15,6 @@ cfg_if::cfg_if! { target_os = "espidf", ))] { // These "unix" family members do not have unwinder. - // Note this also matches x86_64-unknown-none-linuxkernel. } else if #[cfg(any( unix, windows, |