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/alloc.rs | 438 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 438 insertions(+) create mode 100644 rust/alloc/alloc.rs (limited to 'rust/alloc/alloc.rs') diff --git a/rust/alloc/alloc.rs b/rust/alloc/alloc.rs new file mode 100644 index 000000000000..6162b5c6d4c9 --- /dev/null +++ b/rust/alloc/alloc.rs @@ -0,0 +1,438 @@ +//! Memory allocation APIs + +#![stable(feature = "alloc_module", since = "1.28.0")] + +#[cfg(not(test))] +use core::intrinsics; +use core::intrinsics::{min_align_of_val, size_of_val}; + +use core::ptr::Unique; +#[cfg(not(test))] +use core::ptr::{self, NonNull}; + +#[stable(feature = "alloc_module", since = "1.28.0")] +#[doc(inline)] +pub use core::alloc::*; + +use core::marker::Destruct; + +#[cfg(test)] +mod tests; + +extern "Rust" { + // These are the magic symbols to call the global allocator. rustc generates + // them to call `__rg_alloc` etc. if there is a `#[global_allocator]` attribute + // (the code expanding that attribute macro generates those functions), or to call + // the default implementations in libstd (`__rdl_alloc` etc. in `library/std/src/alloc.rs`) + // otherwise. + // The rustc fork of LLVM also special-cases these function names to be able to optimize them + // like `malloc`, `realloc`, and `free`, respectively. + #[rustc_allocator] + #[rustc_allocator_nounwind] + fn __rust_alloc(size: usize, align: usize) -> *mut u8; + #[rustc_allocator_nounwind] + fn __rust_dealloc(ptr: *mut u8, size: usize, align: usize); + #[rustc_allocator_nounwind] + fn __rust_realloc(ptr: *mut u8, old_size: usize, align: usize, new_size: usize) -> *mut u8; + #[rustc_allocator_nounwind] + fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8; +} + +/// The global memory allocator. +/// +/// This type implements the [`Allocator`] trait by forwarding calls +/// to the allocator registered with the `#[global_allocator]` attribute +/// if there is one, or the `std` crate’s default. +/// +/// Note: while this type is unstable, the functionality it provides can be +/// accessed through the [free functions in `alloc`](self#functions). +#[unstable(feature = "allocator_api", issue = "32838")] +#[derive(Copy, Clone, Default, Debug)] +#[cfg(not(test))] +pub struct Global; + +#[cfg(test)] +pub use std::alloc::Global; + +/// Allocate memory with the global allocator. +/// +/// This function forwards calls to the [`GlobalAlloc::alloc`] method +/// of the allocator registered with the `#[global_allocator]` attribute +/// if there is one, or the `std` crate’s default. +/// +/// This function is expected to be deprecated in favor of the `alloc` method +/// of the [`Global`] type when it and the [`Allocator`] trait become stable. +/// +/// # Safety +/// +/// See [`GlobalAlloc::alloc`]. +/// +/// # Examples +/// +/// ``` +/// use std::alloc::{alloc, dealloc, Layout}; +/// +/// unsafe { +/// let layout = Layout::new::(); +/// let ptr = alloc(layout); +/// +/// *(ptr as *mut u16) = 42; +/// assert_eq!(*(ptr as *mut u16), 42); +/// +/// dealloc(ptr, layout); +/// } +/// ``` +#[stable(feature = "global_alloc", since = "1.28.0")] +#[must_use = "losing the pointer will leak memory"] +#[inline] +pub unsafe fn alloc(layout: Layout) -> *mut u8 { + unsafe { __rust_alloc(layout.size(), layout.align()) } +} + +/// Deallocate memory with the global allocator. +/// +/// This function forwards calls to the [`GlobalAlloc::dealloc`] method +/// of the allocator registered with the `#[global_allocator]` attribute +/// if there is one, or the `std` crate’s default. +/// +/// This function is expected to be deprecated in favor of the `dealloc` method +/// of the [`Global`] type when it and the [`Allocator`] trait become stable. +/// +/// # Safety +/// +/// See [`GlobalAlloc::dealloc`]. +#[stable(feature = "global_alloc", since = "1.28.0")] +#[inline] +pub unsafe fn dealloc(ptr: *mut u8, layout: Layout) { + unsafe { __rust_dealloc(ptr, layout.size(), layout.align()) } +} + +/// Reallocate memory with the global allocator. +/// +/// This function forwards calls to the [`GlobalAlloc::realloc`] method +/// of the allocator registered with the `#[global_allocator]` attribute +/// if there is one, or the `std` crate’s default. +/// +/// This function is expected to be deprecated in favor of the `realloc` method +/// of the [`Global`] type when it and the [`Allocator`] trait become stable. +/// +/// # Safety +/// +/// See [`GlobalAlloc::realloc`]. +#[stable(feature = "global_alloc", since = "1.28.0")] +#[must_use = "losing the pointer will leak memory"] +#[inline] +pub unsafe fn realloc(ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 { + unsafe { __rust_realloc(ptr, layout.size(), layout.align(), new_size) } +} + +/// Allocate zero-initialized memory with the global allocator. +/// +/// This function forwards calls to the [`GlobalAlloc::alloc_zeroed`] method +/// of the allocator registered with the `#[global_allocator]` attribute +/// if there is one, or the `std` crate’s default. +/// +/// This function is expected to be deprecated in favor of the `alloc_zeroed` method +/// of the [`Global`] type when it and the [`Allocator`] trait become stable. +/// +/// # Safety +/// +/// See [`GlobalAlloc::alloc_zeroed`]. +/// +/// # Examples +/// +/// ``` +/// use std::alloc::{alloc_zeroed, dealloc, Layout}; +/// +/// unsafe { +/// let layout = Layout::new::(); +/// let ptr = alloc_zeroed(layout); +/// +/// assert_eq!(*(ptr as *mut u16), 0); +/// +/// dealloc(ptr, layout); +/// } +/// ``` +#[stable(feature = "global_alloc", since = "1.28.0")] +#[must_use = "losing the pointer will leak memory"] +#[inline] +pub unsafe fn alloc_zeroed(layout: Layout) -> *mut u8 { + unsafe { __rust_alloc_zeroed(layout.size(), layout.align()) } +} + +#[cfg(not(test))] +impl Global { + #[inline] + fn alloc_impl(&self, layout: Layout, zeroed: bool) -> Result, AllocError> { + match layout.size() { + 0 => Ok(NonNull::slice_from_raw_parts(layout.dangling(), 0)), + // SAFETY: `layout` is non-zero in size, + size => unsafe { + let raw_ptr = if zeroed { alloc_zeroed(layout) } else { alloc(layout) }; + let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?; + Ok(NonNull::slice_from_raw_parts(ptr, size)) + }, + } + } + + // SAFETY: Same as `Allocator::grow` + #[inline] + unsafe fn grow_impl( + &self, + ptr: NonNull, + old_layout: Layout, + new_layout: Layout, + zeroed: bool, + ) -> Result, AllocError> { + debug_assert!( + new_layout.size() >= old_layout.size(), + "`new_layout.size()` must be greater than or equal to `old_layout.size()`" + ); + + match old_layout.size() { + 0 => self.alloc_impl(new_layout, zeroed), + + // SAFETY: `new_size` is non-zero as `old_size` is greater than or equal to `new_size` + // as required by safety conditions. Other conditions must be upheld by the caller + old_size if old_layout.align() == new_layout.align() => unsafe { + 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()); + + let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size); + let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?; + if zeroed { + raw_ptr.add(old_size).write_bytes(0, new_size - old_size); + } + Ok(NonNull::slice_from_raw_parts(ptr, new_size)) + }, + + // SAFETY: because `new_layout.size()` must be greater than or equal to `old_size`, + // both the old and new memory allocation are valid for reads and writes for `old_size` + // bytes. Also, because the old allocation wasn't yet deallocated, it cannot overlap + // `new_ptr`. Thus, the call to `copy_nonoverlapping` is safe. The safety contract + // for `dealloc` must be upheld by the caller. + old_size => unsafe { + let new_ptr = self.alloc_impl(new_layout, zeroed)?; + ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), old_size); + self.deallocate(ptr, old_layout); + Ok(new_ptr) + }, + } + } +} + +#[unstable(feature = "allocator_api", issue = "32838")] +#[cfg(not(test))] +unsafe impl Allocator for Global { + #[inline] + fn allocate(&self, layout: Layout) -> Result, AllocError> { + self.alloc_impl(layout, false) + } + + #[inline] + fn allocate_zeroed(&self, layout: Layout) -> Result, AllocError> { + self.alloc_impl(layout, true) + } + + #[inline] + unsafe fn deallocate(&self, ptr: NonNull, layout: Layout) { + if layout.size() != 0 { + // SAFETY: `layout` is non-zero in size, + // other conditions must be upheld by the caller + unsafe { dealloc(ptr.as_ptr(), layout) } + } + } + + #[inline] + unsafe fn grow( + &self, + ptr: NonNull, + old_layout: Layout, + new_layout: Layout, + ) -> Result, AllocError> { + // SAFETY: all conditions must be upheld by the caller + unsafe { self.grow_impl(ptr, old_layout, new_layout, false) } + } + + #[inline] + unsafe fn grow_zeroed( + &self, + ptr: NonNull, + old_layout: Layout, + new_layout: Layout, + ) -> Result, AllocError> { + // SAFETY: all conditions must be upheld by the caller + unsafe { self.grow_impl(ptr, old_layout, new_layout, true) } + } + + #[inline] + unsafe fn shrink( + &self, + ptr: NonNull, + old_layout: Layout, + new_layout: Layout, + ) -> Result, AllocError> { + debug_assert!( + new_layout.size() <= old_layout.size(), + "`new_layout.size()` must be smaller than or equal to `old_layout.size()`" + ); + + match new_layout.size() { + // SAFETY: conditions must be upheld by the caller + 0 => unsafe { + self.deallocate(ptr, old_layout); + Ok(NonNull::slice_from_raw_parts(new_layout.dangling(), 0)) + }, + + // 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()); + + let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size); + let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?; + Ok(NonNull::slice_from_raw_parts(ptr, new_size)) + }, + + // SAFETY: because `new_size` must be smaller than or equal to `old_layout.size()`, + // both the old and new memory allocation are valid for reads and writes for `new_size` + // bytes. Also, because the old allocation wasn't yet deallocated, it cannot overlap + // `new_ptr`. Thus, the call to `copy_nonoverlapping` is safe. The safety contract + // for `dealloc` must be upheld by the caller. + new_size => unsafe { + let new_ptr = self.allocate(new_layout)?; + ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), new_size); + self.deallocate(ptr, old_layout); + Ok(new_ptr) + }, + } + } +} + +/// The allocator for unique pointers. +#[cfg(all(not(no_global_oom_handling), not(test)))] +#[lang = "exchange_malloc"] +#[inline] +unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 { + let layout = unsafe { Layout::from_size_align_unchecked(size, align) }; + match Global.allocate(layout) { + Ok(ptr) => ptr.as_mut_ptr(), + Err(_) => handle_alloc_error(layout), + } +} + +#[cfg_attr(not(test), lang = "box_free")] +#[inline] +#[rustc_const_unstable(feature = "const_box", issue = "92521")] +// 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) const 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()); + let layout = Layout::from_size_align_unchecked(size, align); + alloc.deallocate(From::from(ptr.cast()), layout) + } +} + +// # Allocation error handler + +#[cfg(not(no_global_oom_handling))] +extern "Rust" { + // This is the magic symbol to call the global alloc error handler. rustc generates + // it to call `__rg_oom` if there is a `#[alloc_error_handler]`, or to call the + // default implementations below (`__rdl_oom`) otherwise. + fn __rust_alloc_error_handler(size: usize, align: usize) -> !; +} + +/// Abort on memory allocation error or failure. +/// +/// Callers of memory allocation APIs wishing to abort computation +/// in response to an allocation error are encouraged to call this function, +/// rather than directly invoking `panic!` or similar. +/// +/// The default behavior of this function is to print a message to standard error +/// and abort the process. +/// It can be replaced with [`set_alloc_error_hook`] and [`take_alloc_error_hook`]. +/// +/// [`set_alloc_error_hook`]: ../../std/alloc/fn.set_alloc_error_hook.html +/// [`take_alloc_error_hook`]: ../../std/alloc/fn.take_alloc_error_hook.html +#[stable(feature = "global_alloc", since = "1.28.0")] +#[rustc_const_unstable(feature = "const_alloc_error", issue = "92523")] +#[cfg(all(not(no_global_oom_handling), not(test)))] +#[cold] +pub const fn handle_alloc_error(layout: Layout) -> ! { + const fn ct_error(_: Layout) -> ! { + panic!("allocation failed"); + } + + fn rt_error(layout: Layout) -> ! { + unsafe { + __rust_alloc_error_handler(layout.size(), layout.align()); + } + } + + unsafe { core::intrinsics::const_eval_select((layout,), ct_error, rt_error) } +} + +// For alloc test `std::alloc::handle_alloc_error` can be used directly. +#[cfg(all(not(no_global_oom_handling), test))] +pub use std::alloc::handle_alloc_error; + +#[cfg(all(not(no_global_oom_handling), not(test)))] +#[doc(hidden)] +#[allow(unused_attributes)] +#[unstable(feature = "alloc_internals", issue = "none")] +pub mod __alloc_error_handler { + use crate::alloc::Layout; + + // called via generated `__rust_alloc_error_handler` + + // if there is no `#[alloc_error_handler]` + #[rustc_std_internal_symbol] + pub unsafe extern "C-unwind" fn __rdl_oom(size: usize, _align: usize) -> ! { + panic!("memory allocation of {size} bytes failed") + } + + // if there is an `#[alloc_error_handler]` + #[rustc_std_internal_symbol] + pub unsafe extern "C-unwind" fn __rg_oom(size: usize, align: usize) -> ! { + let layout = unsafe { Layout::from_size_align_unchecked(size, align) }; + extern "Rust" { + #[lang = "oom"] + fn oom_impl(layout: Layout) -> !; + } + unsafe { oom_impl(layout) } + } +} + +/// Specialize clones into pre-allocated, uninitialized memory. +/// Used by `Box::clone` and `Rc`/`Arc::make_mut`. +pub(crate) trait WriteCloneIntoRaw: Sized { + unsafe fn write_clone_into_raw(&self, target: *mut Self); +} + +impl WriteCloneIntoRaw for T { + #[inline] + default unsafe fn write_clone_into_raw(&self, target: *mut Self) { + // Having allocated *first* may allow the optimizer to create + // the cloned value in-place, skipping the local and move. + unsafe { target.write(self.clone()) }; + } +} + +impl WriteCloneIntoRaw for T { + #[inline] + unsafe fn write_clone_into_raw(&self, target: *mut Self) { + // We can always copy in-place, without ever involving a local value. + unsafe { target.copy_from_nonoverlapping(self, 1) }; + } +} -- 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/alloc.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