From 753dece88d70a23b015e01674a662e683235c08f Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Fri, 6 May 2022 17:52:44 +0200 Subject: rust: import upstream `alloc` crate This is a subset of the Rust standard library `alloc` crate, version 1.62.0, licensed under "Apache-2.0 OR MIT", from: https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src The files are copied as-is, with no modifications whatsoever (not even adding the SPDX identifiers). For copyright details, please see: https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT The next patch modifies these files as needed for use within the kernel. This patch split allows reviewers to double-check the import and to clearly see the differences introduced. Vendoring `alloc`, at least for the moment, allows us to have fallible allocations support (i.e. the `try_*` versions of methods which return a `Result` instead of panicking) early on. It also gives a bit more freedom to experiment with new interfaces and to iterate quickly. Eventually, the goal is to have everything the kernel needs in upstream `alloc` and drop it from the kernel tree. For a summary of work on `alloc` happening upstream, please see: https://github.com/Rust-for-Linux/linux/issues/408 The following script may be used to verify the contents: for path in $(cd rust/alloc/ && find . -type f -name '*.rs'); do curl --silent --show-error --location \ https://github.com/rust-lang/rust/raw/1.62.0/library/alloc/src/$path \ | diff --unified rust/alloc/$path - && echo $path: OK done Reviewed-by: Kees Cook Co-developed-by: Alex Gaynor Signed-off-by: Alex Gaynor Co-developed-by: Wedson Almeida Filho Signed-off-by: Wedson Almeida Filho Signed-off-by: Miguel Ojeda --- rust/alloc/raw_vec.rs | 518 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 518 insertions(+) create mode 100644 rust/alloc/raw_vec.rs (limited to 'rust/alloc/raw_vec.rs') diff --git a/rust/alloc/raw_vec.rs b/rust/alloc/raw_vec.rs new file mode 100644 index 000000000000..4be5f6cf9ca5 --- /dev/null +++ b/rust/alloc/raw_vec.rs @@ -0,0 +1,518 @@ +#![unstable(feature = "raw_vec_internals", reason = "unstable const warnings", issue = "none")] + +use core::alloc::LayoutError; +use core::cmp; +use core::intrinsics; +use core::mem::{self, ManuallyDrop, MaybeUninit}; +use core::ops::Drop; +use core::ptr::{self, NonNull, Unique}; +use core::slice; + +#[cfg(not(no_global_oom_handling))] +use crate::alloc::handle_alloc_error; +use crate::alloc::{Allocator, Global, Layout}; +use crate::boxed::Box; +use crate::collections::TryReserveError; +use crate::collections::TryReserveErrorKind::*; + +#[cfg(test)] +mod tests; + +#[cfg(not(no_global_oom_handling))] +enum AllocInit { + /// The contents of the new memory are uninitialized. + Uninitialized, + /// The new memory is guaranteed to be zeroed. + Zeroed, +} + +/// A low-level utility for more ergonomically allocating, reallocating, and deallocating +/// a buffer of memory on the heap without having to worry about all the corner cases +/// involved. This type is excellent for building your own data structures like Vec and VecDeque. +/// In particular: +/// +/// * Produces `Unique::dangling()` on zero-sized types. +/// * Produces `Unique::dangling()` on zero-length allocations. +/// * Avoids freeing `Unique::dangling()`. +/// * Catches all overflows in capacity computations (promotes them to "capacity overflow" panics). +/// * Guards against 32-bit systems allocating more than isize::MAX bytes. +/// * Guards against overflowing your length. +/// * Calls `handle_alloc_error` for fallible allocations. +/// * Contains a `ptr::Unique` and thus endows the user with all related benefits. +/// * Uses the excess returned from the allocator to use the largest available capacity. +/// +/// This type does not in anyway inspect the memory that it manages. When dropped it *will* +/// free its memory, but it *won't* try to drop its contents. It is up to the user of `RawVec` +/// to handle the actual things *stored* inside of a `RawVec`. +/// +/// Note that the excess of a zero-sized types is always infinite, so `capacity()` always returns +/// `usize::MAX`. This means that you need to be careful when round-tripping this type with a +/// `Box<[T]>`, since `capacity()` won't yield the length. +#[allow(missing_debug_implementations)] +pub(crate) struct RawVec { + ptr: Unique, + cap: usize, + alloc: A, +} + +impl RawVec { + /// HACK(Centril): This exists because stable `const fn` can only call stable `const fn`, so + /// they cannot call `Self::new()`. + /// + /// If you change `RawVec::new` or dependencies, please take care to not introduce anything + /// that would truly const-call something unstable. + pub const NEW: Self = Self::new(); + + /// Creates the biggest possible `RawVec` (on the system heap) + /// without allocating. If `T` has positive size, then this makes a + /// `RawVec` with capacity `0`. If `T` is zero-sized, then it makes a + /// `RawVec` with capacity `usize::MAX`. Useful for implementing + /// delayed allocation. + #[must_use] + pub const fn new() -> Self { + Self::new_in(Global) + } + + /// Creates a `RawVec` (on the system heap) with exactly the + /// capacity and alignment requirements for a `[T; capacity]`. This is + /// equivalent to calling `RawVec::new` when `capacity` is `0` or `T` is + /// zero-sized. Note that if `T` is zero-sized this means you will + /// *not* get a `RawVec` with the requested capacity. + /// + /// # Panics + /// + /// Panics if the requested capacity exceeds `isize::MAX` bytes. + /// + /// # Aborts + /// + /// Aborts on OOM. + #[cfg(not(any(no_global_oom_handling, test)))] + #[must_use] + #[inline] + pub fn with_capacity(capacity: usize) -> Self { + Self::with_capacity_in(capacity, Global) + } + + /// Like `with_capacity`, but guarantees the buffer is zeroed. + #[cfg(not(any(no_global_oom_handling, test)))] + #[must_use] + #[inline] + pub fn with_capacity_zeroed(capacity: usize) -> Self { + Self::with_capacity_zeroed_in(capacity, Global) + } +} + +impl RawVec { + // Tiny Vecs are dumb. Skip to: + // - 8 if the element size is 1, because any heap allocators is likely + // to round up a request of less than 8 bytes to at least 8 bytes. + // - 4 if elements are moderate-sized (<= 1 KiB). + // - 1 otherwise, to avoid wasting too much space for very short Vecs. + pub(crate) const MIN_NON_ZERO_CAP: usize = if mem::size_of::() == 1 { + 8 + } else if mem::size_of::() <= 1024 { + 4 + } else { + 1 + }; + + /// Like `new`, but parameterized over the choice of allocator for + /// the returned `RawVec`. + pub const fn new_in(alloc: A) -> Self { + // `cap: 0` means "unallocated". zero-sized types are ignored. + Self { ptr: Unique::dangling(), cap: 0, alloc } + } + + /// Like `with_capacity`, but parameterized over the choice of + /// allocator for the returned `RawVec`. + #[cfg(not(no_global_oom_handling))] + #[inline] + pub fn with_capacity_in(capacity: usize, alloc: A) -> Self { + Self::allocate_in(capacity, AllocInit::Uninitialized, alloc) + } + + /// Like `with_capacity_zeroed`, but parameterized over the choice + /// of allocator for the returned `RawVec`. + #[cfg(not(no_global_oom_handling))] + #[inline] + pub fn with_capacity_zeroed_in(capacity: usize, alloc: A) -> Self { + Self::allocate_in(capacity, AllocInit::Zeroed, alloc) + } + + /// Converts the entire buffer into `Box<[MaybeUninit]>` with the specified `len`. + /// + /// Note that this will correctly reconstitute any `cap` changes + /// that may have been performed. (See description of type for details.) + /// + /// # Safety + /// + /// * `len` must be greater than or equal to the most recently requested capacity, and + /// * `len` must be less than or equal to `self.capacity()`. + /// + /// Note, that the requested capacity and `self.capacity()` could differ, as + /// an allocator could overallocate and return a greater memory block than requested. + pub unsafe fn into_box(self, len: usize) -> Box<[MaybeUninit], A> { + // Sanity-check one half of the safety requirement (we cannot check the other half). + debug_assert!( + len <= self.capacity(), + "`len` must be smaller than or equal to `self.capacity()`" + ); + + let me = ManuallyDrop::new(self); + unsafe { + let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit, len); + Box::from_raw_in(slice, ptr::read(&me.alloc)) + } + } + + #[cfg(not(no_global_oom_handling))] + fn allocate_in(capacity: usize, init: AllocInit, alloc: A) -> Self { + // Don't allocate here because `Drop` will not deallocate when `capacity` is 0. + if mem::size_of::() == 0 || capacity == 0 { + Self::new_in(alloc) + } else { + // We avoid `unwrap_or_else` here because it bloats the amount of + // LLVM IR generated. + let layout = match Layout::array::(capacity) { + Ok(layout) => layout, + Err(_) => capacity_overflow(), + }; + match alloc_guard(layout.size()) { + Ok(_) => {} + Err(_) => capacity_overflow(), + } + let result = match init { + AllocInit::Uninitialized => alloc.allocate(layout), + AllocInit::Zeroed => alloc.allocate_zeroed(layout), + }; + let ptr = match result { + Ok(ptr) => ptr, + Err(_) => handle_alloc_error(layout), + }; + + // Allocators currently return a `NonNull<[u8]>` whose length + // matches the size requested. If that ever changes, the capacity + // here should change to `ptr.len() / mem::size_of::()`. + Self { + ptr: unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) }, + cap: capacity, + alloc, + } + } + } + + /// Reconstitutes a `RawVec` from a pointer, capacity, and allocator. + /// + /// # Safety + /// + /// The `ptr` must be allocated (via the given allocator `alloc`), and with the given + /// `capacity`. + /// The `capacity` cannot exceed `isize::MAX` for sized types. (only a concern on 32-bit + /// systems). ZST vectors may have a capacity up to `usize::MAX`. + /// If the `ptr` and `capacity` come from a `RawVec` created via `alloc`, then this is + /// guaranteed. + #[inline] + pub unsafe fn from_raw_parts_in(ptr: *mut T, capacity: usize, alloc: A) -> Self { + Self { ptr: unsafe { Unique::new_unchecked(ptr) }, cap: capacity, alloc } + } + + /// Gets a raw pointer to the start of the allocation. Note that this is + /// `Unique::dangling()` if `capacity == 0` or `T` is zero-sized. In the former case, you must + /// be careful. + #[inline] + pub fn ptr(&self) -> *mut T { + self.ptr.as_ptr() + } + + /// Gets the capacity of the allocation. + /// + /// This will always be `usize::MAX` if `T` is zero-sized. + #[inline(always)] + pub fn capacity(&self) -> usize { + if mem::size_of::() == 0 { usize::MAX } else { self.cap } + } + + /// Returns a shared reference to the allocator backing this `RawVec`. + pub fn allocator(&self) -> &A { + &self.alloc + } + + fn current_memory(&self) -> Option<(NonNull, Layout)> { + if mem::size_of::() == 0 || self.cap == 0 { + None + } else { + // We have an allocated chunk of memory, so we can bypass runtime + // checks to get our current layout. + unsafe { + let layout = Layout::array::(self.cap).unwrap_unchecked(); + Some((self.ptr.cast().into(), layout)) + } + } + } + + /// Ensures that the buffer contains at least enough space to hold `len + + /// additional` elements. If it doesn't already have enough capacity, will + /// reallocate enough space plus comfortable slack space to get amortized + /// *O*(1) behavior. Will limit this behavior if it would needlessly cause + /// itself to panic. + /// + /// If `len` exceeds `self.capacity()`, this may fail to actually allocate + /// the requested space. This is not really unsafe, but the unsafe + /// code *you* write that relies on the behavior of this function may break. + /// + /// This is ideal for implementing a bulk-push operation like `extend`. + /// + /// # Panics + /// + /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// + /// # Aborts + /// + /// Aborts on OOM. + #[cfg(not(no_global_oom_handling))] + #[inline] + pub fn reserve(&mut self, len: usize, additional: usize) { + // Callers expect this function to be very cheap when there is already sufficient capacity. + // Therefore, we move all the resizing and error-handling logic from grow_amortized and + // handle_reserve behind a call, while making sure that this function is likely to be + // inlined as just a comparison and a call if the comparison fails. + #[cold] + fn do_reserve_and_handle( + slf: &mut RawVec, + len: usize, + additional: usize, + ) { + handle_reserve(slf.grow_amortized(len, additional)); + } + + if self.needs_to_grow(len, additional) { + do_reserve_and_handle(self, len, additional); + } + } + + /// A specialized version of `reserve()` used only by the hot and + /// oft-instantiated `Vec::push()`, which does its own capacity check. + #[cfg(not(no_global_oom_handling))] + #[inline(never)] + pub fn reserve_for_push(&mut self, len: usize) { + handle_reserve(self.grow_amortized(len, 1)); + } + + /// The same as `reserve`, but returns on errors instead of panicking or aborting. + pub fn try_reserve(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> { + if self.needs_to_grow(len, additional) { + self.grow_amortized(len, additional) + } else { + Ok(()) + } + } + + /// Ensures that the buffer contains at least enough space to hold `len + + /// additional` elements. If it doesn't already, will reallocate the + /// minimum possible amount of memory necessary. Generally this will be + /// exactly the amount of memory necessary, but in principle the allocator + /// is free to give back more than we asked for. + /// + /// If `len` exceeds `self.capacity()`, this may fail to actually allocate + /// the requested space. This is not really unsafe, but the unsafe code + /// *you* write that relies on the behavior of this function may break. + /// + /// # Panics + /// + /// Panics if the new capacity exceeds `isize::MAX` bytes. + /// + /// # Aborts + /// + /// Aborts on OOM. + #[cfg(not(no_global_oom_handling))] + pub fn reserve_exact(&mut self, len: usize, additional: usize) { + handle_reserve(self.try_reserve_exact(len, additional)); + } + + /// The same as `reserve_exact`, but returns on errors instead of panicking or aborting. + pub fn try_reserve_exact( + &mut self, + len: usize, + additional: usize, + ) -> Result<(), TryReserveError> { + if self.needs_to_grow(len, additional) { self.grow_exact(len, additional) } else { Ok(()) } + } + + /// Shrinks the buffer down to the specified capacity. If the given amount + /// is 0, actually completely deallocates. + /// + /// # Panics + /// + /// Panics if the given amount is *larger* than the current capacity. + /// + /// # Aborts + /// + /// Aborts on OOM. + #[cfg(not(no_global_oom_handling))] + pub fn shrink_to_fit(&mut self, cap: usize) { + handle_reserve(self.shrink(cap)); + } +} + +impl RawVec { + /// Returns if the buffer needs to grow to fulfill the needed extra capacity. + /// Mainly used to make inlining reserve-calls possible without inlining `grow`. + fn needs_to_grow(&self, len: usize, additional: usize) -> bool { + additional > self.capacity().wrapping_sub(len) + } + + fn set_ptr_and_cap(&mut self, ptr: NonNull<[u8]>, cap: usize) { + // Allocators currently return a `NonNull<[u8]>` whose length matches + // the size requested. If that ever changes, the capacity here should + // change to `ptr.len() / mem::size_of::()`. + self.ptr = unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) }; + self.cap = cap; + } + + // This method is usually instantiated many times. So we want it to be as + // small as possible, to improve compile times. But we also want as much of + // its contents to be statically computable as possible, to make the + // generated code run faster. Therefore, this method is carefully written + // so that all of the code that depends on `T` is within it, while as much + // of the code that doesn't depend on `T` as possible is in functions that + // are non-generic over `T`. + fn grow_amortized(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> { + // This is ensured by the calling contexts. + debug_assert!(additional > 0); + + if mem::size_of::() == 0 { + // Since we return a capacity of `usize::MAX` when `elem_size` is + // 0, getting to here necessarily means the `RawVec` is overfull. + return Err(CapacityOverflow.into()); + } + + // Nothing we can really do about these checks, sadly. + let required_cap = len.checked_add(additional).ok_or(CapacityOverflow)?; + + // This guarantees exponential growth. The doubling cannot overflow + // because `cap <= isize::MAX` and the type of `cap` is `usize`. + let cap = cmp::max(self.cap * 2, required_cap); + let cap = cmp::max(Self::MIN_NON_ZERO_CAP, cap); + + let new_layout = Layout::array::(cap); + + // `finish_grow` is non-generic over `T`. + let ptr = finish_grow(new_layout, self.current_memory(), &mut self.alloc)?; + self.set_ptr_and_cap(ptr, cap); + Ok(()) + } + + // The constraints on this method are much the same as those on + // `grow_amortized`, but this method is usually instantiated less often so + // it's less critical. + fn grow_exact(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> { + if mem::size_of::() == 0 { + // Since we return a capacity of `usize::MAX` when the type size is + // 0, getting to here necessarily means the `RawVec` is overfull. + return Err(CapacityOverflow.into()); + } + + let cap = len.checked_add(additional).ok_or(CapacityOverflow)?; + let new_layout = Layout::array::(cap); + + // `finish_grow` is non-generic over `T`. + let ptr = finish_grow(new_layout, self.current_memory(), &mut self.alloc)?; + self.set_ptr_and_cap(ptr, cap); + Ok(()) + } + + fn shrink(&mut self, cap: usize) -> Result<(), TryReserveError> { + assert!(cap <= self.capacity(), "Tried to shrink to a larger capacity"); + + let (ptr, layout) = if let Some(mem) = self.current_memory() { mem } else { return Ok(()) }; + + let ptr = unsafe { + // `Layout::array` cannot overflow here because it would have + // overflowed earlier when capacity was larger. + let new_layout = Layout::array::(cap).unwrap_unchecked(); + self.alloc + .shrink(ptr, layout, new_layout) + .map_err(|_| AllocError { layout: new_layout, non_exhaustive: () })? + }; + self.set_ptr_and_cap(ptr, cap); + Ok(()) + } +} + +// This function is outside `RawVec` to minimize compile times. See the comment +// above `RawVec::grow_amortized` for details. (The `A` parameter isn't +// significant, because the number of different `A` types seen in practice is +// much smaller than the number of `T` types.) +#[inline(never)] +fn finish_grow( + new_layout: Result, + current_memory: Option<(NonNull, Layout)>, + alloc: &mut A, +) -> Result, TryReserveError> +where + A: Allocator, +{ + // Check for the error here to minimize the size of `RawVec::grow_*`. + let new_layout = new_layout.map_err(|_| CapacityOverflow)?; + + alloc_guard(new_layout.size())?; + + let memory = if let Some((ptr, old_layout)) = current_memory { + debug_assert_eq!(old_layout.align(), new_layout.align()); + unsafe { + // The allocator checks for alignment equality + intrinsics::assume(old_layout.align() == new_layout.align()); + alloc.grow(ptr, old_layout, new_layout) + } + } else { + alloc.allocate(new_layout) + }; + + memory.map_err(|_| AllocError { layout: new_layout, non_exhaustive: () }.into()) +} + +unsafe impl<#[may_dangle] T, A: Allocator> Drop for RawVec { + /// Frees the memory owned by the `RawVec` *without* trying to drop its contents. + fn drop(&mut self) { + if let Some((ptr, layout)) = self.current_memory() { + unsafe { self.alloc.deallocate(ptr, layout) } + } + } +} + +// Central function for reserve error handling. +#[cfg(not(no_global_oom_handling))] +#[inline] +fn handle_reserve(result: Result<(), TryReserveError>) { + match result.map_err(|e| e.kind()) { + Err(CapacityOverflow) => capacity_overflow(), + Err(AllocError { layout, .. }) => handle_alloc_error(layout), + Ok(()) => { /* yay */ } + } +} + +// We need to guarantee the following: +// * We don't ever allocate `> isize::MAX` byte-size objects. +// * We don't overflow `usize::MAX` and actually allocate too little. +// +// On 64-bit we just need to check for overflow since trying to allocate +// `> 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 { + Err(CapacityOverflow.into()) + } else { + Ok(()) + } +} + +// One central function responsible for reporting capacity overflows. This'll +// ensure that the code generation related to these panics is minimal as there's +// only one location which panics rather than a bunch throughout the module. +#[cfg(not(no_global_oom_handling))] +fn capacity_overflow() -> ! { + panic!("capacity overflow"); +} -- cgit v1.2.3 From 057b8d2571071da05d06810ca70f26c6316f6ea7 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sat, 3 Jul 2021 17:02:21 +0200 Subject: rust: adapt `alloc` crate to the kernel This customizes the subset of the Rust standard library `alloc` that was just imported as-is, mainly by: - Adding SPDX license identifiers. - Skipping modules (e.g. `rc` and `sync`) via new `cfg`s. - Adding fallible (`try_*`) versions of existing infallible methods (i.e. returning a `Result` instead of panicking). Since the standard library requires stable/unstable attributes, these additions are annotated with: #[stable(feature = "kernel", since = "1.0.0")] Using "kernel" as the feature allows to have the additions clearly marked. The "1.0.0" version is just a placeholder. (At the moment, only one is needed, but in the future more fallible methods will be added). Reviewed-by: Greg Kroah-Hartman Co-developed-by: Alex Gaynor Signed-off-by: Alex Gaynor Co-developed-by: Wedson Almeida Filho Signed-off-by: Wedson Almeida Filho Co-developed-by: Gary Guo Signed-off-by: Gary Guo Co-developed-by: Matthew Bakhtiari Signed-off-by: Matthew Bakhtiari Signed-off-by: Miguel Ojeda --- rust/alloc/README.md | 33 +++++++++++++++++++++++++++++++++ rust/alloc/alloc.rs | 2 ++ rust/alloc/borrow.rs | 4 +++- rust/alloc/boxed.rs | 4 ++++ rust/alloc/collections/mod.rs | 2 ++ rust/alloc/lib.rs | 8 ++++++++ rust/alloc/raw_vec.rs | 9 +++++++++ rust/alloc/slice.rs | 2 ++ rust/alloc/vec/drain.rs | 2 ++ rust/alloc/vec/drain_filter.rs | 2 ++ rust/alloc/vec/into_iter.rs | 4 ++++ rust/alloc/vec/is_zero.rs | 2 ++ rust/alloc/vec/mod.rs | 25 +++++++++++++++++++++++++ rust/alloc/vec/partial_eq.rs | 2 ++ 14 files changed, 100 insertions(+), 1 deletion(-) create mode 100644 rust/alloc/README.md (limited to 'rust/alloc/raw_vec.rs') diff --git a/rust/alloc/README.md b/rust/alloc/README.md new file mode 100644 index 000000000000..c89c753720b5 --- /dev/null +++ b/rust/alloc/README.md @@ -0,0 +1,33 @@ +# `alloc` + +These source files come from the Rust standard library, hosted in +the repository, licensed under +"Apache-2.0 OR MIT" and adapted for kernel use. For copyright details, +see . + +Please note that these files should be kept as close as possible to +upstream. In general, only additions should be performed (e.g. new +methods). Eventually, changes should make it into upstream so that, +at some point, this fork can be dropped from the kernel tree. + + +## Rationale + +On one hand, kernel folks wanted to keep `alloc` in-tree to have more +freedom in both workflow and actual features if actually needed +(e.g. receiver types if we ended up using them), which is reasonable. + +On the other hand, Rust folks wanted to keep `alloc` as close as +upstream as possible and avoid as much divergence as possible, which +is also reasonable. + +We agreed on a middle-ground: we would keep a subset of `alloc` +in-tree that would be as small and as close as possible to upstream. +Then, upstream can start adding the functions that we add to `alloc` +etc., until we reach a point where the kernel already knows exactly +what it needs in `alloc` and all the new methods are merged into +upstream, so that we can drop `alloc` from the kernel tree and go back +to using the upstream one. + +By doing this, the kernel can go a bit faster now, and Rust can +slowly incorporate and discuss the changes as needed. diff --git a/rust/alloc/alloc.rs b/rust/alloc/alloc.rs index 6162b5c6d4c9..ca224a541770 100644 --- a/rust/alloc/alloc.rs +++ b/rust/alloc/alloc.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! Memory allocation APIs #![stable(feature = "alloc_module", since = "1.28.0")] diff --git a/rust/alloc/borrow.rs b/rust/alloc/borrow.rs index cb4e438f8bea..dde4957200d4 100644 --- a/rust/alloc/borrow.rs +++ b/rust/alloc/borrow.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! A module for working with borrowed data. #![stable(feature = "rust1", since = "1.0.0")] @@ -11,7 +13,7 @@ use core::ops::{Add, AddAssign}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::borrow::{Borrow, BorrowMut}; -use crate::fmt; +use core::fmt; #[cfg(not(no_global_oom_handling))] use crate::string::String; diff --git a/rust/alloc/boxed.rs b/rust/alloc/boxed.rs index c07536f0d0ce..dcfe87b14f3a 100644 --- a/rust/alloc/boxed.rs +++ b/rust/alloc/boxed.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! A pointer type for heap allocation. //! //! [`Box`], casually referred to as a 'box', provides the simplest form of @@ -163,9 +165,11 @@ use crate::str::from_boxed_utf8_unchecked; #[cfg(not(no_global_oom_handling))] use crate::vec::Vec; +#[cfg(not(no_thin))] #[unstable(feature = "thin_box", issue = "92791")] pub use thin::ThinBox; +#[cfg(not(no_thin))] mod thin; /// A pointer type for heap allocation. diff --git a/rust/alloc/collections/mod.rs b/rust/alloc/collections/mod.rs index 628a5b155673..1eec265b28f8 100644 --- a/rust/alloc/collections/mod.rs +++ b/rust/alloc/collections/mod.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! Collection types. #![stable(feature = "rust1", since = "1.0.0")] diff --git a/rust/alloc/lib.rs b/rust/alloc/lib.rs index fd21b3671182..233bcd5e4654 100644 --- a/rust/alloc/lib.rs +++ b/rust/alloc/lib.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! # The Rust core allocation and collections library //! //! This library provides smart pointers and collections for managing @@ -192,6 +194,7 @@ extern crate std; extern crate test; // Module with internal macros used by other modules (needs to be included before other modules). +#[cfg(not(no_macros))] #[macro_use] mod macros; @@ -216,11 +219,16 @@ pub mod borrow; pub mod collections; #[cfg(not(no_global_oom_handling))] pub mod ffi; +#[cfg(not(no_fmt))] pub mod fmt; +#[cfg(not(no_rc))] pub mod rc; pub mod slice; +#[cfg(not(no_str))] pub mod str; +#[cfg(not(no_string))] pub mod string; +#[cfg(not(no_sync))] #[cfg(target_has_atomic = "ptr")] pub mod sync; #[cfg(all(not(no_global_oom_handling), target_has_atomic = "ptr"))] diff --git a/rust/alloc/raw_vec.rs b/rust/alloc/raw_vec.rs index 4be5f6cf9ca5..daf5f2da7168 100644 --- a/rust/alloc/raw_vec.rs +++ b/rust/alloc/raw_vec.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + #![unstable(feature = "raw_vec_internals", reason = "unstable const warnings", issue = "none")] use core::alloc::LayoutError; @@ -307,6 +309,12 @@ impl RawVec { } } + /// The same as `reserve_for_push`, but returns on errors instead of panicking or aborting. + #[inline(never)] + pub fn try_reserve_for_push(&mut self, len: usize) -> Result<(), TryReserveError> { + self.grow_amortized(len, 1) + } + /// Ensures that the buffer contains at least enough space to hold `len + /// additional` elements. If it doesn't already, will reallocate the /// minimum possible amount of memory necessary. Generally this will be @@ -421,6 +429,7 @@ impl RawVec { Ok(()) } + #[allow(dead_code)] fn shrink(&mut self, cap: usize) -> Result<(), TryReserveError> { assert!(cap <= self.capacity(), "Tried to shrink to a larger capacity"); diff --git a/rust/alloc/slice.rs b/rust/alloc/slice.rs index 199b3c9d0290..e444e97fa145 100644 --- a/rust/alloc/slice.rs +++ b/rust/alloc/slice.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! A dynamically-sized view into a contiguous sequence, `[T]`. //! //! *[See also the slice primitive type](slice).* diff --git a/rust/alloc/vec/drain.rs b/rust/alloc/vec/drain.rs index 5cdee0bd4da4..b6a5f98e4fcd 100644 --- a/rust/alloc/vec/drain.rs +++ b/rust/alloc/vec/drain.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + use crate::alloc::{Allocator, Global}; use core::fmt; use core::iter::{FusedIterator, TrustedLen}; diff --git a/rust/alloc/vec/drain_filter.rs b/rust/alloc/vec/drain_filter.rs index 3c37c92ae44b..b04fce041622 100644 --- a/rust/alloc/vec/drain_filter.rs +++ b/rust/alloc/vec/drain_filter.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + use crate::alloc::{Allocator, Global}; use core::ptr::{self}; use core::slice::{self}; diff --git a/rust/alloc/vec/into_iter.rs b/rust/alloc/vec/into_iter.rs index 9b84a1d9b4b6..f7a50e76691e 100644 --- a/rust/alloc/vec/into_iter.rs +++ b/rust/alloc/vec/into_iter.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + #[cfg(not(no_global_oom_handling))] use super::AsVecIntoIter; use crate::alloc::{Allocator, Global}; @@ -9,6 +11,7 @@ use core::iter::{ }; use core::marker::PhantomData; use core::mem::{self, ManuallyDrop}; +#[cfg(not(no_global_oom_handling))] use core::ops::Deref; use core::ptr::{self, NonNull}; use core::slice::{self}; @@ -123,6 +126,7 @@ impl IntoIter { } /// Forgets to Drop the remaining elements while still allowing the backing allocation to be freed. + #[allow(dead_code)] pub(crate) fn forget_remaining_elements(&mut self) { self.ptr = self.end; } diff --git a/rust/alloc/vec/is_zero.rs b/rust/alloc/vec/is_zero.rs index edf270db81d4..377f3d172777 100644 --- a/rust/alloc/vec/is_zero.rs +++ b/rust/alloc/vec/is_zero.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + use crate::boxed::Box; #[rustc_specialization_trait] diff --git a/rust/alloc/vec/mod.rs b/rust/alloc/vec/mod.rs index 3dc8a4fbba86..540787804cc2 100644 --- a/rust/alloc/vec/mod.rs +++ b/rust/alloc/vec/mod.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! A contiguous growable array type with heap-allocated contents, written //! `Vec`. //! @@ -1739,6 +1741,29 @@ impl Vec { } } + /// Tries to append an element to the back of a collection. + /// + /// # Examples + /// + /// ``` + /// let mut vec = vec![1, 2]; + /// vec.try_push(3).unwrap(); + /// assert_eq!(vec, [1, 2, 3]); + /// ``` + #[inline] + #[stable(feature = "kernel", since = "1.0.0")] + pub fn try_push(&mut self, value: T) -> Result<(), TryReserveError> { + if self.len == self.buf.capacity() { + self.buf.try_reserve_for_push(self.len)?; + } + unsafe { + let end = self.as_mut_ptr().add(self.len); + ptr::write(end, value); + self.len += 1; + } + Ok(()) + } + /// Removes the last element from a vector and returns it, or [`None`] if it /// is empty. /// diff --git a/rust/alloc/vec/partial_eq.rs b/rust/alloc/vec/partial_eq.rs index b0cf72577a1b..10ad4e492287 100644 --- a/rust/alloc/vec/partial_eq.rs +++ b/rust/alloc/vec/partial_eq.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + use crate::alloc::Allocator; #[cfg(not(no_global_oom_handling))] use crate::borrow::Cow; -- cgit v1.2.3