Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Make functions part of alloc_layout_extra (#55724) const. #99016

Closed
wants to merge 1 commit into from
Closed

Make functions part of alloc_layout_extra (#55724) const. #99016

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 19 additions & 10 deletions library/core/src/alloc/layout.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,3 @@
use crate::cmp;
use crate::fmt;
use crate::mem::{self, ValidAlign};
use crate::ptr::NonNull;
Expand Down Expand Up @@ -211,9 +210,13 @@ impl Layout {
/// Returns an error if the combination of `self.size()` and the given
/// `align` violates the conditions listed in [`Layout::from_size_align`].
#[stable(feature = "alloc_layout_manipulation", since = "1.44.0")]
#[rustc_const_unstable(feature = "alloc_layout_extra", issue = "55724")]
#[inline]
pub fn align_to(&self, align: usize) -> Result<Self, LayoutError> {
Layout::from_size_align(self.size(), cmp::max(self.align(), align))
pub const fn align_to(&self, align: usize) -> Result<Self, LayoutError> {
Layout::from_size_align(
self.size(),
if self.align() >= align { self.align() } else { align },
)
}

/// Returns the amount of padding we must insert after `self`
Expand Down Expand Up @@ -269,10 +272,11 @@ impl Layout {
/// This is equivalent to adding the result of `padding_needed_for`
/// to the layout's current size.
#[stable(feature = "alloc_layout_manipulation", since = "1.44.0")]
#[rustc_const_unstable(feature = "alloc_layout_extra", issue = "55724")]
#[must_use = "this returns a new `Layout`, \
without modifying the original"]
#[inline]
pub fn pad_to_align(&self) -> Layout {
pub const fn pad_to_align(&self) -> Layout {
let pad = self.padding_needed_for(self.align());
// This cannot overflow. Quoting from the invariant of Layout:
// > `size`, when rounded up to the nearest multiple of `align`,
Expand All @@ -294,8 +298,9 @@ impl Layout {
///
/// On arithmetic overflow, returns `LayoutError`.
#[unstable(feature = "alloc_layout_extra", issue = "55724")]
#[rustc_const_unstable(feature = "alloc_layout_extra", issue = "55724")]
#[inline]
pub fn repeat(&self, n: usize) -> Result<(Self, usize), LayoutError> {
pub const fn repeat(&self, n: usize) -> Result<(Self, usize), LayoutError> {
// This cannot overflow. Quoting from the invariant of Layout:
// > `size`, when rounded up to the nearest multiple of `align`,
// > must not overflow (i.e., the rounded value must be less than
Expand Down Expand Up @@ -354,9 +359,10 @@ impl Layout {
/// # assert_eq!(repr_c(&[u64, u32, u16, u32]), Ok((s, vec![0, 8, 12, 16])));
/// ```
#[stable(feature = "alloc_layout_manipulation", since = "1.44.0")]
#[rustc_const_unstable(feature = "alloc_layout_extra", issue = "55724")]
#[inline]
pub fn extend(&self, next: Self) -> Result<(Self, usize), LayoutError> {
let new_align = cmp::max(self.align(), next.align());
pub const fn extend(&self, next: Self) -> Result<(Self, usize), LayoutError> {
let new_align = if self.align() >= next.align() { self.align() } else { next.align() };
let pad = self.padding_needed_for(next.align());

let offset = self.size().checked_add(pad).ok_or(LayoutError)?;
Expand All @@ -379,8 +385,9 @@ impl Layout {
///
/// On arithmetic overflow, returns `LayoutError`.
#[unstable(feature = "alloc_layout_extra", issue = "55724")]
#[rustc_const_unstable(feature = "alloc_layout_extra", issue = "55724")]
#[inline]
pub fn repeat_packed(&self, n: usize) -> Result<Self, LayoutError> {
pub const fn repeat_packed(&self, n: usize) -> Result<Self, LayoutError> {
let size = self.size().checked_mul(n).ok_or(LayoutError)?;
Layout::from_size_align(size, self.align())
}
Expand All @@ -392,8 +399,9 @@ impl Layout {
///
/// On arithmetic overflow, returns `LayoutError`.
#[unstable(feature = "alloc_layout_extra", issue = "55724")]
#[rustc_const_unstable(feature = "alloc_layout_extra", issue = "55724")]
#[inline]
pub fn extend_packed(&self, next: Self) -> Result<Self, LayoutError> {
pub const fn extend_packed(&self, next: Self) -> Result<Self, LayoutError> {
let new_size = self.size().checked_add(next.size()).ok_or(LayoutError)?;
Layout::from_size_align(new_size, self.align())
}
Expand All @@ -402,8 +410,9 @@ impl Layout {
///
/// On arithmetic overflow, returns `LayoutError`.
#[stable(feature = "alloc_layout_manipulation", since = "1.44.0")]
#[rustc_const_unstable(feature = "alloc_layout_extra", issue = "55724")]
#[inline]
pub fn array<T>(n: usize) -> Result<Self, LayoutError> {
pub const fn array<T>(n: usize) -> Result<Self, LayoutError> {
let array_size = mem::size_of::<T>().checked_mul(n).ok_or(LayoutError)?;

// SAFETY:
Expand Down
2 changes: 2 additions & 0 deletions library/core/src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,7 @@
// Library features:
#![feature(const_align_offset)]
#![feature(const_align_of_val)]
#![feature(const_alloc_layout)]
#![feature(const_arguments_as_str)]
#![feature(const_array_into_iter_constructors)]
#![feature(const_bigint_helper_methods)]
Expand Down Expand Up @@ -139,6 +140,7 @@
#![feature(const_str_from_utf8_unchecked_mut)]
#![feature(const_swap)]
#![feature(const_trait_impl)]
#![feature(const_try)]
#![feature(const_type_id)]
#![feature(const_type_name)]
#![feature(const_default_impls)]
Expand Down