diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index b48da698d6f253..7aeb97560dd7a8 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) 11.0.0 clang --version -Rust (optional) 1.71.1 rustc --version +Rust (optional) 1.72.0 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 0b6bf5b6da4345..51821feb20b1b2 100644 --- a/rust/alloc/alloc.rs +++ b/rust/alloc/alloc.rs @@ -6,8 +6,10 @@ #[cfg(not(test))] use core::intrinsics; +#[cfg(all(bootstrap, not(test)))] use core::intrinsics::{min_align_of_val, size_of_val}; +#[cfg(all(bootstrap, not(test)))] use core::ptr::Unique; #[cfg(not(test))] use core::ptr::{self, NonNull}; @@ -40,7 +42,6 @@ extern "Rust" { #[rustc_nounwind] fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8; - #[cfg(not(bootstrap))] static __rust_no_alloc_shim_is_unstable: u8; } @@ -98,7 +99,6 @@ pub unsafe fn alloc(layout: Layout) -> *mut u8 { unsafe { // Make sure we don't accidentally allow omitting the allocator shim in // stable code until it is actually stabilized. - #[cfg(not(bootstrap))] core::ptr::read_volatile(&__rust_no_alloc_shim_is_unstable); __rust_alloc(layout.size(), layout.align()) @@ -339,14 +339,15 @@ unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 { } } -#[cfg_attr(not(test), lang = "box_free")] +#[cfg(all(bootstrap, not(test)))] +#[lang = "box_free"] #[inline] // This signature has to be the same as `Box`, otherwise an ICE will happen. // When an additional parameter to `Box` is added (like `A: Allocator`), this has to be added here as // well. // For example if `Box` is changed to `struct Box(Unique, A)`, // this function has to be changed to `fn box_free(Unique, A)` as well. -pub(crate) unsafe fn box_free(ptr: Unique, alloc: A) { +unsafe fn box_free(ptr: Unique, alloc: A) { unsafe { let size = size_of_val(ptr.as_ref()); let align = min_align_of_val(ptr.as_ref()); diff --git a/rust/alloc/boxed.rs b/rust/alloc/boxed.rs index c8173cea831773..bdab710f77374b 100644 --- a/rust/alloc/boxed.rs +++ b/rust/alloc/boxed.rs @@ -1215,8 +1215,16 @@ impl Box { #[stable(feature = "rust1", since = "1.0.0")] unsafe impl<#[may_dangle] T: ?Sized, A: Allocator> Drop for Box { + #[inline] fn drop(&mut self) { - // FIXME: Do nothing, drop is currently performed by compiler. + // the T in the Box is dropped by the compiler before the destructor is run + + let ptr = self.0; + + unsafe { + let layout = Layout::for_value_raw(ptr.as_ptr()); + self.1.deallocate(From::from(ptr.cast()), layout) + } } } diff --git a/rust/alloc/lib.rs b/rust/alloc/lib.rs index 85e91356ecb308..115fcb053e73ad 100644 --- a/rust/alloc/lib.rs +++ b/rust/alloc/lib.rs @@ -58,6 +58,11 @@ //! [`Rc`]: rc //! [`RefCell`]: core::cell +// To run alloc tests without x.py without ending up with two copies of alloc, Miri needs to be +// able to "empty" this crate. See . +// rustc itself never sets the feature, so this line has no affect there. +#![cfg(any(not(feature = "miri-test-libstd"), test, doctest))] +// #![allow(unused_attributes)] #![stable(feature = "alloc", since = "1.36.0")] #![doc( @@ -77,11 +82,6 @@ ))] #![no_std] #![needs_allocator] -// To run alloc tests without x.py without ending up with two copies of alloc, Miri needs to be -// able to "empty" this crate. See . -// rustc itself never sets the feature, so this line has no affect there. -#![cfg(any(not(feature = "miri-test-libstd"), test, doctest))] -// // Lints: #![deny(unsafe_op_in_unsafe_fn)] #![deny(fuzzy_provenance_casts)] diff --git a/rust/alloc/vec/drain_filter.rs b/rust/alloc/vec/drain_filter.rs deleted file mode 100644 index 09efff090e428c..00000000000000 --- a/rust/alloc/vec/drain_filter.rs +++ /dev/null @@ -1,199 +0,0 @@ -// SPDX-License-Identifier: Apache-2.0 OR MIT - -use crate::alloc::{Allocator, Global}; -use core::mem::{ManuallyDrop, SizedTypeProperties}; -use core::ptr; -use core::slice; - -use super::Vec; - -/// An iterator which uses a closure to determine if an element should be removed. -/// -/// This struct is created by [`Vec::drain_filter`]. -/// See its documentation for more. -/// -/// # Example -/// -/// ``` -/// #![feature(drain_filter)] -/// -/// let mut v = vec![0, 1, 2]; -/// let iter: std::vec::DrainFilter<'_, _, _> = v.drain_filter(|x| *x % 2 == 0); -/// ``` -#[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")] -#[derive(Debug)] -pub struct DrainFilter< - 'a, - T, - F, - #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global, -> where - F: FnMut(&mut T) -> bool, -{ - pub(super) vec: &'a mut Vec, - /// The index of the item that will be inspected by the next call to `next`. - pub(super) idx: usize, - /// The number of items that have been drained (removed) thus far. - pub(super) del: usize, - /// The original length of `vec` prior to draining. - pub(super) old_len: usize, - /// The filter test predicate. - pub(super) pred: F, - /// A flag that indicates a panic has occurred in the filter test predicate. - /// This is used as a hint in the drop implementation to prevent consumption - /// of the remainder of the `DrainFilter`. Any unprocessed items will be - /// backshifted in the `vec`, but no further items will be dropped or - /// tested by the filter predicate. - pub(super) panic_flag: bool, -} - -impl DrainFilter<'_, T, F, A> -where - F: FnMut(&mut T) -> bool, -{ - /// Returns a reference to the underlying allocator. - #[unstable(feature = "allocator_api", issue = "32838")] - #[inline] - pub fn allocator(&self) -> &A { - self.vec.allocator() - } - - /// Keep unyielded elements in the source `Vec`. - /// - /// # Examples - /// - /// ``` - /// #![feature(drain_filter)] - /// #![feature(drain_keep_rest)] - /// - /// let mut vec = vec!['a', 'b', 'c']; - /// let mut drain = vec.drain_filter(|_| true); - /// - /// assert_eq!(drain.next().unwrap(), 'a'); - /// - /// // This call keeps 'b' and 'c' in the vec. - /// drain.keep_rest(); - /// - /// // If we wouldn't call `keep_rest()`, - /// // `vec` would be empty. - /// assert_eq!(vec, ['b', 'c']); - /// ``` - #[unstable(feature = "drain_keep_rest", issue = "101122")] - pub fn keep_rest(self) { - // At this moment layout looks like this: - // - // _____________________/-- old_len - // / \ - // [kept] [yielded] [tail] - // \_______/ ^-- idx - // \-- del - // - // Normally `Drop` impl would drop [tail] (via .for_each(drop), ie still calling `pred`) - // - // 1. Move [tail] after [kept] - // 2. Update length of the original vec to `old_len - del` - // a. In case of ZST, this is the only thing we want to do - // 3. Do *not* drop self, as everything is put in a consistent state already, there is nothing to do - let mut this = ManuallyDrop::new(self); - - unsafe { - // ZSTs have no identity, so we don't need to move them around. - if !T::IS_ZST && this.idx < this.old_len && this.del > 0 { - let ptr = this.vec.as_mut_ptr(); - let src = ptr.add(this.idx); - let dst = src.sub(this.del); - let tail_len = this.old_len - this.idx; - src.copy_to(dst, tail_len); - } - - let new_len = this.old_len - this.del; - this.vec.set_len(new_len); - } - } -} - -#[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")] -impl Iterator for DrainFilter<'_, T, F, A> -where - F: FnMut(&mut T) -> bool, -{ - type Item = T; - - fn next(&mut self) -> Option { - unsafe { - while self.idx < self.old_len { - let i = self.idx; - let v = slice::from_raw_parts_mut(self.vec.as_mut_ptr(), self.old_len); - self.panic_flag = true; - let drained = (self.pred)(&mut v[i]); - self.panic_flag = false; - // Update the index *after* the predicate is called. If the index - // is updated prior and the predicate panics, the element at this - // index would be leaked. - self.idx += 1; - if drained { - self.del += 1; - return Some(ptr::read(&v[i])); - } else if self.del > 0 { - let del = self.del; - let src: *const T = &v[i]; - let dst: *mut T = &mut v[i - del]; - ptr::copy_nonoverlapping(src, dst, 1); - } - } - None - } - } - - fn size_hint(&self) -> (usize, Option) { - (0, Some(self.old_len - self.idx)) - } -} - -#[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")] -impl Drop for DrainFilter<'_, T, F, A> -where - F: FnMut(&mut T) -> bool, -{ - fn drop(&mut self) { - struct BackshiftOnDrop<'a, 'b, T, F, A: Allocator> - where - F: FnMut(&mut T) -> bool, - { - drain: &'b mut DrainFilter<'a, T, F, A>, - } - - impl<'a, 'b, T, F, A: Allocator> Drop for BackshiftOnDrop<'a, 'b, T, F, A> - where - F: FnMut(&mut T) -> bool, - { - fn drop(&mut self) { - unsafe { - if self.drain.idx < self.drain.old_len && self.drain.del > 0 { - // This is a pretty messed up state, and there isn't really an - // obviously right thing to do. We don't want to keep trying - // to execute `pred`, so we just backshift all the unprocessed - // elements and tell the vec that they still exist. The backshift - // is required to prevent a double-drop of the last successfully - // drained item prior to a panic in the predicate. - let ptr = self.drain.vec.as_mut_ptr(); - let src = ptr.add(self.drain.idx); - let dst = src.sub(self.drain.del); - let tail_len = self.drain.old_len - self.drain.idx; - src.copy_to(dst, tail_len); - } - self.drain.vec.set_len(self.drain.old_len - self.drain.del); - } - } - } - - let backshift = BackshiftOnDrop { drain: self }; - - // Attempt to consume any remaining elements if the filter predicate - // has not yet panicked. We'll backshift any remaining elements - // whether we've already panicked or if the consumption here panics. - if !backshift.drain.panic_flag { - backshift.drain.for_each(drop); - } - } -} diff --git a/rust/alloc/vec/extract_if.rs b/rust/alloc/vec/extract_if.rs new file mode 100644 index 00000000000000..f314a51d4d3dbb --- /dev/null +++ b/rust/alloc/vec/extract_if.rs @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use crate::alloc::{Allocator, Global}; +use core::ptr; +use core::slice; + +use super::Vec; + +/// An iterator which uses a closure to determine if an element should be removed. +/// +/// This struct is created by [`Vec::extract_if`]. +/// See its documentation for more. +/// +/// # Example +/// +/// ``` +/// #![feature(extract_if)] +/// +/// let mut v = vec![0, 1, 2]; +/// let iter: std::vec::ExtractIf<'_, _, _> = v.extract_if(|x| *x % 2 == 0); +/// ``` +#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")] +#[derive(Debug)] +#[must_use = "iterators are lazy and do nothing unless consumed"] +pub struct ExtractIf< + 'a, + T, + F, + #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global, +> where + F: FnMut(&mut T) -> bool, +{ + pub(super) vec: &'a mut Vec, + /// The index of the item that will be inspected by the next call to `next`. + pub(super) idx: usize, + /// The number of items that have been drained (removed) thus far. + pub(super) del: usize, + /// The original length of `vec` prior to draining. + pub(super) old_len: usize, + /// The filter test predicate. + pub(super) pred: F, +} + +impl ExtractIf<'_, T, F, A> +where + F: FnMut(&mut T) -> bool, +{ + /// Returns a reference to the underlying allocator. + #[unstable(feature = "allocator_api", issue = "32838")] + #[inline] + pub fn allocator(&self) -> &A { + self.vec.allocator() + } +} + +#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")] +impl Iterator for ExtractIf<'_, T, F, A> +where + F: FnMut(&mut T) -> bool, +{ + type Item = T; + + fn next(&mut self) -> Option { + unsafe { + while self.idx < self.old_len { + let i = self.idx; + let v = slice::from_raw_parts_mut(self.vec.as_mut_ptr(), self.old_len); + let drained = (self.pred)(&mut v[i]); + // Update the index *after* the predicate is called. If the index + // is updated prior and the predicate panics, the element at this + // index would be leaked. + self.idx += 1; + if drained { + self.del += 1; + return Some(ptr::read(&v[i])); + } else if self.del > 0 { + let del = self.del; + let src: *const T = &v[i]; + let dst: *mut T = &mut v[i - del]; + ptr::copy_nonoverlapping(src, dst, 1); + } + } + None + } + } + + fn size_hint(&self) -> (usize, Option) { + (0, Some(self.old_len - self.idx)) + } +} + +#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")] +impl Drop for ExtractIf<'_, T, F, A> +where + F: FnMut(&mut T) -> bool, +{ + fn drop(&mut self) { + unsafe { + if self.idx < self.old_len && self.del > 0 { + // This is a pretty messed up state, and there isn't really an + // obviously right thing to do. We don't want to keep trying + // to execute `pred`, so we just backshift all the unprocessed + // elements and tell the vec that they still exist. The backshift + // is required to prevent a double-drop of the last successfully + // drained item prior to a panic in the predicate. + let ptr = self.vec.as_mut_ptr(); + let src = ptr.add(self.idx); + let dst = src.sub(self.del); + let tail_len = self.old_len - self.idx; + src.copy_to(dst, tail_len); + } + self.vec.set_len(self.old_len - self.del); + } + } +} diff --git a/rust/alloc/vec/mod.rs b/rust/alloc/vec/mod.rs index 05c70de0227ed3..a4e9a5002a6d16 100644 --- a/rust/alloc/vec/mod.rs +++ b/rust/alloc/vec/mod.rs @@ -74,10 +74,10 @@ use crate::boxed::Box; use crate::collections::{TryReserveError, TryReserveErrorKind}; use crate::raw_vec::RawVec; -#[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")] -pub use self::drain_filter::DrainFilter; +#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")] +pub use self::extract_if::ExtractIf; -mod drain_filter; +mod extract_if; #[cfg(not(no_global_oom_handling))] #[stable(feature = "vec_splice", since = "1.21.0")] @@ -618,22 +618,20 @@ impl Vec { /// Using memory that was allocated elsewhere: /// /// ```rust - /// #![feature(allocator_api)] - /// - /// use std::alloc::{AllocError, Allocator, Global, Layout}; + /// use std::alloc::{alloc, Layout}; /// /// fn main() { /// let layout = Layout::array::(16).expect("overflow cannot happen"); /// /// let vec = unsafe { - /// let mem = match Global.allocate(layout) { - /// Ok(mem) => mem.cast::().as_ptr(), - /// Err(AllocError) => return, - /// }; + /// let mem = alloc(layout).cast::(); + /// if mem.is_null() { + /// return; + /// } /// /// mem.write(1_000_000); /// - /// Vec::from_raw_parts_in(mem, 1, 16, Global) + /// Vec::from_raw_parts(mem, 1, 16) /// }; /// /// assert_eq!(vec, &[1_000_000]); @@ -876,19 +874,22 @@ impl Vec { /// Using memory that was allocated elsewhere: /// /// ```rust - /// use std::alloc::{alloc, Layout}; + /// #![feature(allocator_api)] + /// + /// use std::alloc::{AllocError, Allocator, Global, Layout}; /// /// fn main() { /// let layout = Layout::array::(16).expect("overflow cannot happen"); + /// /// let vec = unsafe { - /// let mem = alloc(layout).cast::(); - /// if mem.is_null() { - /// return; - /// } + /// let mem = match Global.allocate(layout) { + /// Ok(mem) => mem.cast::().as_ptr(), + /// Err(AllocError) => return, + /// }; /// /// mem.write(1_000_000); /// - /// Vec::from_raw_parts(mem, 1, 16) + /// Vec::from_raw_parts_in(mem, 1, 16, Global) /// }; /// /// assert_eq!(vec, &[1_000_000]); @@ -2507,7 +2508,7 @@ impl Vec { let len = self.len(); if new_len > len { - self.extend_with(new_len - len, ExtendElement(value)) + self.extend_with(new_len - len, value) } else { self.truncate(new_len); } @@ -2545,7 +2546,7 @@ impl Vec { let len = self.len(); if new_len > len { - self.try_extend_with(new_len - len, ExtendElement(value)) + self.try_extend_with(new_len - len, value) } else { self.truncate(new_len); Ok(()) @@ -2684,26 +2685,10 @@ impl Vec<[T; N], A> { } } -// This code generalizes `extend_with_{element,default}`. -trait ExtendWith { - fn next(&mut self) -> T; - fn last(self) -> T; -} - -struct ExtendElement(T); -impl ExtendWith for ExtendElement { - fn next(&mut self) -> T { - self.0.clone() - } - fn last(self) -> T { - self.0 - } -} - -impl Vec { +impl Vec { #[cfg(not(no_global_oom_handling))] - /// Extend the vector by `n` values, using the given generator. - fn extend_with>(&mut self, n: usize, mut value: E) { + /// Extend the vector by `n` clones of value. + fn extend_with(&mut self, n: usize, value: T) { self.reserve(n); unsafe { @@ -2715,15 +2700,15 @@ impl Vec { // Write all elements except the last one for _ in 1..n { - ptr::write(ptr, value.next()); + ptr::write(ptr, value.clone()); ptr = ptr.add(1); - // Increment the length in every step in case next() panics + // Increment the length in every step in case clone() panics local_len.increment_len(1); } if n > 0 { // We can write the last element directly without cloning needlessly - ptr::write(ptr, value.last()); + ptr::write(ptr, value); local_len.increment_len(1); } @@ -2731,8 +2716,8 @@ impl Vec { } } - /// Try to extend the vector by `n` values, using the given generator. - fn try_extend_with>(&mut self, n: usize, mut value: E) -> Result<(), TryReserveError> { + /// Try to extend the vector by `n` clones of value. + fn try_extend_with(&mut self, n: usize, value: T) -> Result<(), TryReserveError> { self.try_reserve(n)?; unsafe { @@ -2744,15 +2729,15 @@ impl Vec { // Write all elements except the last one for _ in 1..n { - ptr::write(ptr, value.next()); + ptr::write(ptr, value.clone()); ptr = ptr.add(1); - // Increment the length in every step in case next() panics + // Increment the length in every step in case clone() panics local_len.increment_len(1); } if n > 0 { // We can write the last element directly without cloning needlessly - ptr::write(ptr, value.last()); + ptr::write(ptr, value); local_len.increment_len(1); } @@ -3210,6 +3195,12 @@ impl Vec { /// If the closure returns false, the element will remain in the vector and will not be yielded /// by the iterator. /// + /// If the returned `ExtractIf` is not exhausted, e.g. because it is dropped without iterating + /// or the iteration short-circuits, then the remaining elements will be retained. + /// Use [`retain`] with a negated predicate if you do not need the returned iterator. + /// + /// [`retain`]: Vec::retain + /// /// Using this method is equivalent to the following code: /// /// ``` @@ -3228,10 +3219,10 @@ impl Vec { /// # assert_eq!(vec, vec![1, 4, 5]); /// ``` /// - /// But `drain_filter` is easier to use. `drain_filter` is also more efficient, + /// But `extract_if` is easier to use. `extract_if` is also more efficient, /// because it can backshift the elements of the array in bulk. /// - /// Note that `drain_filter` also lets you mutate every element in the filter closure, + /// Note that `extract_if` also lets you mutate every element in the filter closure, /// regardless of whether you choose to keep or remove it. /// /// # Examples @@ -3239,17 +3230,17 @@ impl Vec { /// Splitting an array into evens and odds, reusing the original allocation: /// /// ``` - /// #![feature(drain_filter)] + /// #![feature(extract_if)] /// let mut numbers = vec![1, 2, 3, 4, 5, 6, 8, 9, 11, 13, 14, 15]; /// - /// let evens = numbers.drain_filter(|x| *x % 2 == 0).collect::>(); + /// let evens = numbers.extract_if(|x| *x % 2 == 0).collect::>(); /// let odds = numbers; /// /// assert_eq!(evens, vec![2, 4, 6, 8, 14]); /// assert_eq!(odds, vec![1, 3, 5, 9, 11, 13, 15]); /// ``` - #[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")] - pub fn drain_filter(&mut self, filter: F) -> DrainFilter<'_, T, F, A> + #[unstable(feature = "extract_if", reason = "recently added", issue = "43244")] + pub fn extract_if(&mut self, filter: F) -> ExtractIf<'_, T, F, A> where F: FnMut(&mut T) -> bool, { @@ -3260,7 +3251,7 @@ impl Vec { self.set_len(0); } - DrainFilter { vec: self, idx: 0, del: 0, old_len, pred: filter, panic_flag: false } + ExtractIf { vec: self, idx: 0, del: 0, old_len, pred: filter } } } @@ -3290,9 +3281,14 @@ impl<'a, T: Copy + 'a, A: Allocator + 'a> Extend<&'a T> for Vec { /// Implements comparison of vectors, [lexicographically](Ord#lexicographical-comparison). #[stable(feature = "rust1", since = "1.0.0")] -impl PartialOrd for Vec { +impl PartialOrd> for Vec +where + T: PartialOrd, + A1: Allocator, + A2: Allocator, +{ #[inline] - fn partial_cmp(&self, other: &Self) -> Option { + fn partial_cmp(&self, other: &Vec) -> Option { PartialOrd::partial_cmp(&**self, &**other) } } diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index d65ab8bfeaf4b5..9520612dd3982b 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -31,7 +31,7 @@ llvm) fi ;; rustc) - echo 1.71.1 + echo 1.72.0 ;; bindgen) echo 0.65.1