diff options
| -rw-r--r-- | Documentation/process/changes.rst | 2 | ||||
| -rw-r--r-- | rust/alloc/alloc.rs | 6 | ||||
| -rw-r--r-- | rust/alloc/boxed.rs | 4 | ||||
| -rw-r--r-- | rust/alloc/lib.rs | 7 | ||||
| -rw-r--r-- | rust/alloc/raw_vec.rs | 13 | ||||
| -rw-r--r-- | rust/alloc/slice.rs | 4 | ||||
| -rw-r--r-- | rust/alloc/vec/into_iter.rs | 108 | ||||
| -rw-r--r-- | rust/alloc/vec/mod.rs | 101 | ||||
| -rw-r--r-- | rust/kernel/lib.rs | 1 | ||||
| -rw-r--r-- | scripts/Makefile.build | 2 | ||||
| -rwxr-xr-x | scripts/min-tool-version.sh | 2 |
11 files changed, 160 insertions, 90 deletions
diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 7ef8de58f7f8..b5d3107c6734 100644 --- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -31,7 +31,7 @@ you probably needn't concern yourself with pcmciautils. ====================== =============== ======================================== GNU C 5.1 gcc --version Clang/LLVM (optional) 13.0.1 clang --version -Rust (optional) 1.76.0 rustc --version +Rust (optional) 1.77.1 rustc --version bindgen (optional) 0.65.1 bindgen --version GNU make 3.82 make --version bash 4.2 bash --version diff --git a/rust/alloc/alloc.rs b/rust/alloc/alloc.rs index abb791cc2371..b1204f87227b 100644 --- a/rust/alloc/alloc.rs +++ b/rust/alloc/alloc.rs @@ -5,7 +5,7 @@ #![stable(feature = "alloc_module", since = "1.28.0")] #[cfg(not(test))] -use core::intrinsics; +use core::hint; #[cfg(not(test))] use core::ptr::{self, NonNull}; @@ -210,7 +210,7 @@ impl Global { let new_size = new_layout.size(); // `realloc` probably checks for `new_size >= old_layout.size()` or something similar. - intrinsics::assume(new_size >= old_layout.size()); + hint::assert_unchecked(new_size >= old_layout.size()); let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size); let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?; @@ -301,7 +301,7 @@ unsafe impl Allocator for Global { // SAFETY: `new_size` is non-zero. Other conditions must be upheld by the caller new_size if old_layout.align() == new_layout.align() => unsafe { // `realloc` probably checks for `new_size <= old_layout.size()` or something similar. - intrinsics::assume(new_size <= old_layout.size()); + hint::assert_unchecked(new_size <= old_layout.size()); let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size); let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?; diff --git a/rust/alloc/boxed.rs b/rust/alloc/boxed.rs index c93a22a5c97f..5fc39dfeb8e7 100644 --- a/rust/alloc/boxed.rs +++ b/rust/alloc/boxed.rs @@ -26,6 +26,7 @@ //! Creating a recursive data structure: //! //! ``` +//! ##[allow(dead_code)] //! #[derive(Debug)] //! enum List<T> { //! Cons(T, Box<List<T>>), @@ -194,8 +195,7 @@ mod thin; #[fundamental] #[stable(feature = "rust1", since = "1.0.0")] // The declaration of the `Box` struct must be kept in sync with the -// `alloc::alloc::box_free` function or ICEs will happen. See the comment -// on `box_free` for more details. +// compiler or ICEs will happen. pub struct Box< T: ?Sized, #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global, diff --git a/rust/alloc/lib.rs b/rust/alloc/lib.rs index 36f79c075593..39afd55ec074 100644 --- a/rust/alloc/lib.rs +++ b/rust/alloc/lib.rs @@ -105,7 +105,6 @@ #![feature(allocator_api)] #![feature(array_chunks)] #![feature(array_into_iter_constructors)] -#![feature(array_methods)] #![feature(array_windows)] #![feature(ascii_char)] #![feature(assert_matches)] @@ -122,7 +121,6 @@ #![feature(const_size_of_val)] #![feature(const_waker)] #![feature(core_intrinsics)] -#![feature(core_panic)] #![feature(deprecated_suggestion)] #![feature(dispatch_from_dyn)] #![feature(error_generic_member_access)] @@ -132,6 +130,7 @@ #![feature(fmt_internals)] #![feature(fn_traits)] #![feature(hasher_prefixfree_extras)] +#![feature(hint_assert_unchecked)] #![feature(inline_const)] #![feature(inplace_iteration)] #![feature(iter_advance_by)] @@ -141,6 +140,8 @@ #![feature(maybe_uninit_slice)] #![feature(maybe_uninit_uninit_array)] #![feature(maybe_uninit_uninit_array_transpose)] +#![feature(non_null_convenience)] +#![feature(panic_internals)] #![feature(pattern)] #![feature(ptr_internals)] #![feature(ptr_metadata)] @@ -149,7 +150,6 @@ #![feature(set_ptr_value)] #![feature(sized_type_properties)] #![feature(slice_from_ptr_range)] -#![feature(slice_group_by)] #![feature(slice_ptr_get)] #![feature(slice_ptr_len)] #![feature(slice_range)] @@ -182,6 +182,7 @@ #![feature(const_ptr_write)] #![feature(const_trait_impl)] #![feature(const_try)] +#![feature(decl_macro)] #![feature(dropck_eyepatch)] #![feature(exclusive_range_pattern)] #![feature(fundamental)] diff --git a/rust/alloc/raw_vec.rs b/rust/alloc/raw_vec.rs index 98b6abf30af6..1839d1c8ee7a 100644 --- a/rust/alloc/raw_vec.rs +++ b/rust/alloc/raw_vec.rs @@ -4,7 +4,7 @@ use core::alloc::LayoutError; use core::cmp; -use core::intrinsics; +use core::hint; use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties}; use core::ptr::{self, NonNull, Unique}; use core::slice; @@ -317,7 +317,7 @@ impl<T, A: Allocator> RawVec<T, A> { /// /// # Panics /// - /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// Panics if the new capacity exceeds `isize::MAX` _bytes_. /// /// # Aborts /// @@ -358,7 +358,7 @@ impl<T, A: Allocator> RawVec<T, A> { } unsafe { // Inform the optimizer that the reservation has succeeded or wasn't needed - core::intrinsics::assume(!self.needs_to_grow(len, additional)); + hint::assert_unchecked(!self.needs_to_grow(len, additional)); } Ok(()) } @@ -381,7 +381,7 @@ impl<T, A: Allocator> RawVec<T, A> { /// /// # Panics /// - /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// Panics if the new capacity exceeds `isize::MAX` _bytes_. /// /// # Aborts /// @@ -402,7 +402,7 @@ impl<T, A: Allocator> RawVec<T, A> { } unsafe { // Inform the optimizer that the reservation has succeeded or wasn't needed - core::intrinsics::assume(!self.needs_to_grow(len, additional)); + hint::assert_unchecked(!self.needs_to_grow(len, additional)); } Ok(()) } @@ -553,7 +553,7 @@ where debug_assert_eq!(old_layout.align(), new_layout.align()); unsafe { // The allocator checks for alignment equality - intrinsics::assume(old_layout.align() == new_layout.align()); + hint::assert_unchecked(old_layout.align() == new_layout.align()); alloc.grow(ptr, old_layout, new_layout) } } else { @@ -591,7 +591,6 @@ fn handle_reserve(result: Result<(), TryReserveError>) { // `> isize::MAX` bytes will surely fail. On 32-bit and 16-bit we need to add // an extra guard for this in case we're running on a platform which can use // all 4GB in user-space, e.g., PAE or x32. - #[inline] fn alloc_guard(alloc_size: usize) -> Result<(), TryReserveError> { if usize::BITS < 64 && alloc_size > isize::MAX as usize { diff --git a/rust/alloc/slice.rs b/rust/alloc/slice.rs index 1181836da5f4..a36b072c9519 100644 --- a/rust/alloc/slice.rs +++ b/rust/alloc/slice.rs @@ -53,14 +53,14 @@ pub use core::slice::{from_mut, from_ref}; pub use core::slice::{from_mut_ptr_range, from_ptr_range}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::slice::{from_raw_parts, from_raw_parts_mut}; +#[stable(feature = "slice_group_by", since = "1.77.0")] +pub use core::slice::{ChunkBy, ChunkByMut}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::slice::{Chunks, Windows}; #[stable(feature = "chunks_exact", since = "1.31.0")] pub use core::slice::{ChunksExact, ChunksExactMut}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::slice::{ChunksMut, Split, SplitMut}; -#[unstable(feature = "slice_group_by", issue = "80552")] -pub use core::slice::{GroupBy, GroupByMut}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::slice::{Iter, IterMut}; #[stable(feature = "rchunks", since = "1.31.0")] diff --git a/rust/alloc/vec/into_iter.rs b/rust/alloc/vec/into_iter.rs index 136bfe94af6c..0f11744c44b3 100644 --- a/rust/alloc/vec/into_iter.rs +++ b/rust/alloc/vec/into_iter.rs @@ -20,6 +20,17 @@ use core::ops::Deref; use core::ptr::{self, NonNull}; use core::slice::{self}; +macro non_null { + (mut $place:expr, $t:ident) => {{ + #![allow(unused_unsafe)] // we're sometimes used within an unsafe block + unsafe { &mut *(ptr::addr_of_mut!($place) as *mut NonNull<$t>) } + }}, + ($place:expr, $t:ident) => {{ + #![allow(unused_unsafe)] // we're sometimes used within an unsafe block + unsafe { *(ptr::addr_of!($place) as *const NonNull<$t>) } + }}, +} + /// An iterator that moves out of a vector. /// /// This `struct` is created by the `into_iter` method on [`Vec`](super::Vec) @@ -43,10 +54,12 @@ pub struct IntoIter< // the drop impl reconstructs a RawVec from buf, cap and alloc // to avoid dropping the allocator twice we need to wrap it into ManuallyDrop pub(super) alloc: ManuallyDrop<A>, - pub(super) ptr: *const T, - pub(super) end: *const T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that - // ptr == end is a quick test for the Iterator being empty, that works - // for both ZST and non-ZST. + pub(super) ptr: NonNull<T>, + /// If T is a ZST, this is actually ptr+len. This encoding is picked so that + /// ptr == end is a quick test for the Iterator being empty, that works + /// for both ZST and non-ZST. + /// For non-ZSTs the pointer is treated as `NonNull<T>` + pub(super) end: *const T, } #[stable(feature = "vec_intoiter_debug", since = "1.13.0")] @@ -70,7 +83,7 @@ impl<T, A: Allocator> IntoIter<T, A> { /// ``` #[stable(feature = "vec_into_iter_as_slice", since = "1.15.0")] pub fn as_slice(&self) -> &[T] { - unsafe { slice::from_raw_parts(self.ptr, self.len()) } + unsafe { slice::from_raw_parts(self.ptr.as_ptr(), self.len()) } } /// Returns the remaining items of this iterator as a mutable slice. @@ -99,7 +112,7 @@ impl<T, A: Allocator> IntoIter<T, A> { } fn as_raw_mut_slice(&mut self) -> *mut [T] { - ptr::slice_from_raw_parts_mut(self.ptr as *mut T, self.len()) + ptr::slice_from_raw_parts_mut(self.ptr.as_ptr(), self.len()) } /// Drops remaining elements and relinquishes the backing allocation. @@ -126,7 +139,7 @@ impl<T, A: Allocator> IntoIter<T, A> { // this creates less assembly self.cap = 0; self.buf = unsafe { NonNull::new_unchecked(RawVec::NEW.ptr()) }; - self.ptr = self.buf.as_ptr(); + self.ptr = self.buf; self.end = self.buf.as_ptr(); // Dropping the remaining elements can panic, so this needs to be @@ -138,9 +151,9 @@ impl<T, A: Allocator> IntoIter<T, A> { /// Forgets to Drop the remaining elements while still allowing the backing allocation to be freed. pub(crate) fn forget_remaining_elements(&mut self) { - // For th ZST case, it is crucial that we mutate `end` here, not `ptr`. + // For the ZST case, it is crucial that we mutate `end` here, not `ptr`. // `ptr` must stay aligned, while `end` may be unaligned. - self.end = self.ptr; + self.end = self.ptr.as_ptr(); } #[cfg(not(no_global_oom_handling))] @@ -162,7 +175,7 @@ impl<T, A: Allocator> IntoIter<T, A> { // say that they're all at the beginning of the "allocation". 0..this.len() } else { - this.ptr.sub_ptr(buf)..this.end.sub_ptr(buf) + this.ptr.sub_ptr(this.buf)..this.end.sub_ptr(buf) }; let cap = this.cap; let alloc = ManuallyDrop::take(&mut this.alloc); @@ -189,29 +202,35 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> { #[inline] fn next(&mut self) -> Option<T> { - if self.ptr == self.end { - None - } else if T::IS_ZST { - // `ptr` has to stay where it is to remain aligned, so we reduce the length by 1 by - // reducing the `end`. - self.end = self.end.wrapping_byte_sub(1); - - // Make up a value of this ZST. - Some(unsafe { mem::zeroed() }) + if T::IS_ZST { + if self.ptr.as_ptr() == self.end as *mut _ { + None + } else { + // `ptr` has to stay where it is to remain aligned, so we reduce the length by 1 by + // reducing the `end`. + self.end = self.end.wrapping_byte_sub(1); + + // Make up a value of this ZST. + Some(unsafe { mem::zeroed() }) + } } else { - let old = self.ptr; - self.ptr = unsafe { self.ptr.add(1) }; + if self.ptr == non_null!(self.end, T) { + None + } else { + let old = self.ptr; + self.ptr = unsafe { old.add(1) }; - Some(unsafe { ptr::read(old) }) + Some(unsafe { ptr::read(old.as_ptr()) }) + } } } #[inline] fn size_hint(&self) -> (usize, Option<usize>) { let exact = if T::IS_ZST { - self.end.addr().wrapping_sub(self.ptr.addr()) + self.end.addr().wrapping_sub(self.ptr.as_ptr().addr()) } else { - unsafe { self.end.sub_ptr(self.ptr) } + unsafe { non_null!(self.end, T).sub_ptr(self.ptr) } }; (exact, Some(exact)) } @@ -219,7 +238,7 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> { #[inline] fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> { let step_size = self.len().min(n); - let to_drop = ptr::slice_from_raw_parts_mut(self.ptr as *mut T, step_size); + let to_drop = ptr::slice_from_raw_parts_mut(self.ptr.as_ptr(), step_size); if T::IS_ZST { // See `next` for why we sub `end` here. self.end = self.end.wrapping_byte_sub(step_size); @@ -261,7 +280,7 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> { // Safety: `len` indicates that this many elements are available and we just checked that // it fits into the array. unsafe { - ptr::copy_nonoverlapping(self.ptr, raw_ary.as_mut_ptr() as *mut T, len); + ptr::copy_nonoverlapping(self.ptr.as_ptr(), raw_ary.as_mut_ptr() as *mut T, len); self.forget_remaining_elements(); return Err(array::IntoIter::new_unchecked(raw_ary, 0..len)); } @@ -270,7 +289,7 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> { // Safety: `len` is larger than the array size. Copy a fixed amount here to fully initialize // the array. return unsafe { - ptr::copy_nonoverlapping(self.ptr, raw_ary.as_mut_ptr() as *mut T, N); + ptr::copy_nonoverlapping(self.ptr.as_ptr(), raw_ary.as_mut_ptr() as *mut T, N); self.ptr = self.ptr.add(N); Ok(raw_ary.transpose().assume_init()) }; @@ -288,7 +307,7 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> { // Also note the implementation of `Self: TrustedRandomAccess` requires // that `T: Copy` so reading elements from the buffer doesn't invalidate // them for `Drop`. - unsafe { if T::IS_ZST { mem::zeroed() } else { ptr::read(self.ptr.add(i)) } } + unsafe { if T::IS_ZST { mem::zeroed() } else { self.ptr.add(i).read() } } } } @@ -296,18 +315,25 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> { impl<T, A: Allocator> DoubleEndedIterator for IntoIter<T, A> { #[inline] fn next_back(&mut self) -> Option<T> { - if self.end == self.ptr { - None - } else if T::IS_ZST { - // See above for why 'ptr.offset' isn't used - self.end = self.end.wrapping_byte_sub(1); - - // Make up a value of this ZST. - Some(unsafe { mem::zeroed() }) + if T::IS_ZST { + if self.end as *mut _ == self.ptr.as_ptr() { + None + } else { + // See above for why 'ptr.offset' isn't used + self.end = self.end.wrapping_byte_sub(1); + + // Make up a value of this ZST. + Some(unsafe { mem::zeroed() }) + } } else { - self.end = unsafe { self.end.sub(1) }; + if non_null!(self.end, T) == self.ptr { + None + } else { + let new_end = unsafe { non_null!(self.end, T).sub(1) }; + *non_null!(mut self.end, T) = new_end; - Some(unsafe { ptr::read(self.end) }) + Some(unsafe { ptr::read(new_end.as_ptr()) }) + } } } @@ -333,7 +359,11 @@ impl<T, A: Allocator> DoubleEndedIterator for IntoIter<T, A> { #[stable(feature = "rust1", since = "1.0.0")] impl<T, A: Allocator> ExactSizeIterator for IntoIter<T, A> { fn is_empty(&self) -> bool { - self.ptr == self.end + if T::IS_ZST { + self.ptr.as_ptr() == self.end as *mut _ + } else { + self.ptr == non_null!(self.end, T) + } } } diff --git a/rust/alloc/vec/mod.rs b/rust/alloc/vec/mod.rs index 220fb9d6f45b..0be27fff4554 100644 --- a/rust/alloc/vec/mod.rs +++ b/rust/alloc/vec/mod.rs @@ -360,7 +360,7 @@ mod spec_extend; /// /// `vec![x; n]`, `vec![a, b, c, d]`, and /// [`Vec::with_capacity(n)`][`Vec::with_capacity`], will all produce a `Vec` -/// with exactly the requested capacity. If <code>[len] == [capacity]</code>, +/// with at least the requested capacity. If <code>[len] == [capacity]</code>, /// (as is the case for the [`vec!`] macro), then a `Vec<T>` can be converted to /// and from a [`Box<[T]>`][owned slice] without reallocating or moving the elements. /// @@ -447,7 +447,7 @@ impl<T> Vec<T> { /// /// # Panics /// - /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// Panics if the new capacity exceeds `isize::MAX` _bytes_. /// /// # Examples /// @@ -690,7 +690,7 @@ impl<T, A: Allocator> Vec<T, A> { /// /// # Panics /// - /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// Panics if the new capacity exceeds `isize::MAX` _bytes_. /// /// # Examples /// @@ -1013,7 +1013,7 @@ impl<T, A: Allocator> Vec<T, A> { /// /// # Panics /// - /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// Panics if the new capacity exceeds `isize::MAX` _bytes_. /// /// # Examples /// @@ -1043,7 +1043,7 @@ impl<T, A: Allocator> Vec<T, A> { /// /// # Panics /// - /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// Panics if the new capacity exceeds `isize::MAX` _bytes_. /// /// # Examples /// @@ -1140,8 +1140,11 @@ impl<T, A: Allocator> Vec<T, A> { /// Shrinks the capacity of the vector as much as possible. /// - /// It will drop down as close as possible to the length but the allocator - /// may still inform the vector that there is space for a few more elements. + /// The behavior of this method depends on the allocator, which may either shrink the vector + /// in-place or reallocate. The resulting vector might still have some excess capacity, just as + /// is the case for [`with_capacity`]. See [`Allocator::shrink`] for more details. + /// + /// [`with_capacity`]: Vec::with_capacity /// /// # Examples /// @@ -1191,10 +1194,10 @@ impl<T, A: Allocator> Vec<T, A> { /// Converts the vector into [`Box<[T]>`][owned slice]. /// - /// If the vector has excess capacity, its items will be moved into a - /// newly-allocated buffer with exactly the right capacity. + /// Before doing the conversion, this method discards excess capacity like [`shrink_to_fit`]. /// /// [owned slice]: Box + /// [`shrink_to_fit`]: Vec::shrink_to_fit /// /// # Examples /// @@ -2017,7 +2020,7 @@ impl<T, A: Allocator> Vec<T, A> { /// /// # Panics /// - /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// Panics if the new capacity exceeds `isize::MAX` _bytes_. /// /// # Examples /// @@ -2133,7 +2136,7 @@ impl<T, A: Allocator> Vec<T, A> { } else { unsafe { self.len -= 1; - core::intrinsics::assume(self.len < self.capacity()); + core::hint::assert_unchecked(self.len < self.capacity()); Some(ptr::read(self.as_ptr().add(self.len()))) } } @@ -2143,7 +2146,7 @@ impl<T, A: Allocator> Vec<T, A> { /// /// # Panics /// - /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// Panics if the new capacity exceeds `isize::MAX` _bytes_. /// /// # Examples /// @@ -2315,6 +2318,12 @@ impl<T, A: Allocator> Vec<T, A> { /// `[at, len)`. After the call, the original vector will be left containing /// the elements `[0, at)` with its previous capacity unchanged. /// + /// - If you want to take ownership of the entire contents and capacity of + /// the vector, see [`mem::take`] or [`mem::replace`]. + /// - If you don't need the returned vector at all, see [`Vec::truncate`]. + /// - If you want to take ownership of an arbitrary subslice, or you don't + /// necessarily want to store the removed items in a vector, see [`Vec::drain`]. + /// /// # Panics /// /// Panics if `at > len`. @@ -2346,14 +2355,6 @@ impl<T, A: Allocator> Vec<T, A> { assert_failed(at, self.len()); } - if at == 0 { - // the new vector can take over the original buffer and avoid the copy - return mem::replace( - self, - Vec::with_capacity_in(self.capacity(), self.allocator().clone()), - ); - } - let other_len = self.len - at; let mut other = Vec::with_capacity_in(other_len, self.allocator().clone()); @@ -3027,6 +3028,50 @@ impl<T, I: SliceIndex<[T]>, A: Allocator> IndexMut<I> for Vec<T, A> { } } +/// Collects an iterator into a Vec, commonly called via [`Iterator::collect()`] +/// +/// # Allocation behavior +/// +/// In general `Vec` does not guarantee any particular growth or allocation strategy. +/// That also applies to this trait impl. +/// +/// **Note:** This section covers implementation details and is therefore exempt from +/// stability guarantees. +/// +/// Vec may use any or none of the following strategies, +/// depending on the supplied iterator: +/// +/// * preallocate based on [`Iterator::size_hint()`] +/// * and panic if the number of items is outside the provided lower/upper bounds +/// * use an amortized growth strategy similar to `pushing` one item at a time +/// * perform the iteration in-place on the original allocation backing the iterator +/// +/// The last case warrants some attention. It is an optimization that in many cases reduces peak memory +/// consumption and improves cache locality. But when big, short-lived allocations are created, +/// only a small fraction of their items get collected, no further use is made of the spare capacity +/// and the resulting `Vec` is moved into a longer-lived structure, then this can lead to the large +/// allocations having their lifetimes unnecessarily extended which can result in increased memory +/// footprint. +/// +/// In cases where this is an issue, the excess capacity can be discarded with [`Vec::shrink_to()`], +/// [`Vec::shrink_to_fit()`] or by collecting into [`Box<[T]>`][owned slice] instead, which additionally reduces +/// the size of the long-lived struct. +/// +/// [owned slice]: Box +/// +/// ```rust +/// # use std::sync::Mutex; +/// static LONG_LIVED: Mutex<Vec<Vec<u16>>> = Mutex::new(Vec::new()); +/// +/// for i in 0..10 { +/// let big_temporary: Vec<u16> = (0..1024).collect(); +/// // discard most items +/// let mut result: Vec<_> = big_temporary.into_iter().filter(|i| i % 100 == 0).collect(); +/// // without this a lot of unused capacity might be moved into the global +/// result.shrink_to_fit(); +/// LONG_LIVED.lock().unwrap().push(result); +/// } +/// ``` #[cfg(not(no_global_oom_handling))] #[stable(feature = "rust1", since = "1.0.0")] impl<T> FromIterator<T> for Vec<T> { @@ -3069,14 +3114,8 @@ impl<T, A: Allocator> IntoIterator for Vec<T, A> { begin.add(me.len()) as *const T }; let cap = me.buf.capacity(); - IntoIter { - buf: NonNull::new_unchecked(begin), - phantom: PhantomData, - cap, - alloc, - ptr: begin, - end, - } + let buf = NonNull::new_unchecked(begin); + IntoIter { buf, phantom: PhantomData, cap, alloc, ptr: buf, end } } } } @@ -3598,8 +3637,10 @@ impl<T, A: Allocator> From<Box<[T], A>> for Vec<T, A> { impl<T, A: Allocator> From<Vec<T, A>> for Box<[T], A> { /// Convert a vector into a boxed slice. /// - /// If `v` has excess capacity, its items will be moved into a - /// newly-allocated buffer with exactly the right capacity. + /// Before doing the conversion, this method discards excess capacity like [`Vec::shrink_to_fit`]. + /// + /// [owned slice]: Box + /// [`Vec::shrink_to_fit`]: Vec::shrink_to_fit /// /// # Examples /// diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 1952a0df0a15..08dbc3eebaef 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -16,7 +16,6 @@ #![feature(coerce_unsized)] #![feature(dispatch_from_dyn)] #![feature(new_uninit)] -#![feature(offset_of)] #![feature(receiver_trait)] #![feature(unsize)] diff --git a/scripts/Makefile.build b/scripts/Makefile.build index baf86c0880b6..367cfeea74c5 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -263,7 +263,7 @@ $(obj)/%.lst: $(src)/%.c FORCE # Compile Rust sources (.rs) # --------------------------------------------------------------------------- -rust_allowed_features := new_uninit,offset_of +rust_allowed_features := new_uninit # `--out-dir` is required to avoid temporaries being created by `rustc` in the # current working directory, which may be not accessible in the out-of-tree diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index 5927cc6b7de3..6086e00e640e 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -33,7 +33,7 @@ llvm) fi ;; rustc) - echo 1.76.0 + echo 1.77.1 ;; bindgen) echo 0.65.1 |