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Rollup of 5 pull requests #94447

Merged
merged 10 commits into from
Feb 28, 2022
4 changes: 3 additions & 1 deletion compiler/rustc_codegen_llvm/src/back/archive.rs
Original file line number Diff line number Diff line change
@@ -151,7 +151,9 @@ impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> {
output_path.with_extension("lib")
};

let mingw_gnu_toolchain = self.config.sess.target.llvm_target.ends_with("pc-windows-gnu");
let target = &self.config.sess.target;
let mingw_gnu_toolchain =
target.vendor == "pc" && target.os == "windows" && target.env == "gnu";

let import_name_and_ordinal_vector: Vec<(String, Option<u16>)> = dll_imports
.iter()
3 changes: 3 additions & 0 deletions library/core/src/slice/mod.rs
Original file line number Diff line number Diff line change
@@ -71,6 +71,9 @@ pub use raw::{from_raw_parts, from_raw_parts_mut};
#[stable(feature = "from_ref", since = "1.28.0")]
pub use raw::{from_mut, from_ref};

#[unstable(feature = "slice_from_ptr_range", issue = "89792")]
pub use raw::{from_mut_ptr_range, from_ptr_range};

// This function is public only because there is no other way to unit test heapsort.
#[unstable(feature = "sort_internals", reason = "internal to sort module", issue = "none")]
pub use sort::heapsort;
111 changes: 111 additions & 0 deletions library/core/src/slice/raw.rs
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
//! Free functions to create `&[T]` and `&mut [T]`.

use crate::array;
use crate::ops::Range;
use crate::ptr;

/// Forms a slice from a pointer and a length.
@@ -177,3 +178,113 @@ pub const fn from_ref<T>(s: &T) -> &[T] {
pub const fn from_mut<T>(s: &mut T) -> &mut [T] {
array::from_mut(s)
}

/// Forms a slice from a pointer range.
///
/// This function is useful for interacting with foreign interfaces which
/// use two pointers to refer to a range of elements in memory, as is
/// common in C++.
///
/// # Safety
///
/// Behavior is undefined if any of the following conditions are violated:
///
/// * The `start` pointer of the range must be a [valid] and properly aligned pointer
/// to the first element of a slice.
///
/// * The `end` pointer must be a [valid] and properly aligned pointer to *one past*
/// the last element, such that the offset from the end to the start pointer is
/// the length of the slice.
///
/// * The range must contain `N` consecutive properly initialized values of type `T`:
///
/// * The entire memory range of this slice must be contained within a single allocated object!
/// Slices can never span across multiple allocated objects.
///
/// * The memory referenced by the returned slice must not be mutated for the duration
/// of lifetime `'a`, except inside an `UnsafeCell`.
///
/// * The total length of the range must be no larger than `isize::MAX`.
/// See the safety documentation of [`pointer::offset`].
///
/// Note that a range created from [`slice::as_ptr_range`] fulfills these requirements.
///
/// # Caveat
///
/// The lifetime for the returned slice is inferred from its usage. To
/// prevent accidental misuse, it's suggested to tie the lifetime to whichever
/// source lifetime is safe in the context, such as by providing a helper
/// function taking the lifetime of a host value for the slice, or by explicit
/// annotation.
///
/// # Examples
///
/// ```
/// #![feature(slice_from_ptr_range)]
///
/// use core::slice;
///
/// let x = [1, 2, 3];
/// let range = x.as_ptr_range();
///
/// unsafe {
/// assert_eq!(slice::from_ptr_range(range), &x);
/// }
/// ```
///
/// [valid]: ptr#safety
#[unstable(feature = "slice_from_ptr_range", issue = "89792")]
pub unsafe fn from_ptr_range<'a, T>(range: Range<*const T>) -> &'a [T] {
// SAFETY: the caller must uphold the safety contract for `from_ptr_range`.
unsafe { from_raw_parts(range.start, range.end.offset_from(range.start) as usize) }
}

/// Performs the same functionality as [`from_ptr_range`], except that a
/// mutable slice is returned.
///
/// # Safety
///
/// Behavior is undefined if any of the following conditions are violated:
///
/// * The `start` pointer of the range must be a [valid] and properly aligned pointer
/// to the first element of a slice.
///
/// * The `end` pointer must be a [valid] and properly aligned pointer to *one past*
/// the last element, such that the offset from the end to the start pointer is
/// the length of the slice.
///
/// * The range must contain `N` consecutive properly initialized values of type `T`:
///
/// * The entire memory range of this slice must be contained within a single allocated object!
/// Slices can never span across multiple allocated objects.
///
/// * The memory referenced by the returned slice must not be accessed through any other pointer
/// (not derived from the return value) for the duration of lifetime `'a`.
/// Both read and write accesses are forbidden.
///
/// * The total length of the range must be no larger than `isize::MAX`.
/// See the safety documentation of [`pointer::offset`].
///
/// Note that a range created from [`slice::as_mut_ptr_range`] fulfills these requirements.
///
/// # Examples
///
/// ```
/// #![feature(slice_from_ptr_range)]
///
/// use core::slice;
///
/// let mut x = [1, 2, 3];
/// let range = x.as_mut_ptr_range();
///
/// unsafe {
/// assert_eq!(slice::from_mut_ptr_range(range), &mut [1, 2, 3]);
/// }
/// ```
///
/// [valid]: ptr#safety
#[unstable(feature = "slice_from_ptr_range", issue = "89792")]
pub unsafe fn from_mut_ptr_range<'a, T>(range: Range<*mut T>) -> &'a mut [T] {
// SAFETY: the caller must uphold the safety contract for `from_mut_ptr_range`.
unsafe { from_raw_parts_mut(range.start, range.end.offset_from(range.start) as usize) }
}
1 change: 1 addition & 0 deletions library/core/tests/lib.rs
Original file line number Diff line number Diff line change
@@ -46,6 +46,7 @@
#![feature(pin_macro)]
#![feature(sort_internals)]
#![feature(slice_take)]
#![feature(slice_from_ptr_range)]
#![feature(maybe_uninit_uninit_array)]
#![feature(maybe_uninit_array_assume_init)]
#![feature(maybe_uninit_write_slice)]
22 changes: 22 additions & 0 deletions library/core/tests/slice.rs
Original file line number Diff line number Diff line change
@@ -2,6 +2,7 @@ use core::cell::Cell;
use core::cmp::Ordering;
use core::mem::MaybeUninit;
use core::result::Result::{Err, Ok};
use core::slice;

#[test]
fn test_position() {
@@ -2480,3 +2481,24 @@ take_tests! {
(take_mut_oob_max_range_to_inclusive, (..=usize::MAX), None, empty_max_mut!()),
(take_mut_in_bounds_max_range_from, (usize::MAX..), Some(&mut [] as _), empty_max_mut!()),
}

#[test]
fn test_slice_from_ptr_range() {
let arr = ["foo".to_owned(), "bar".to_owned()];
let range = arr.as_ptr_range();
unsafe {
assert_eq!(slice::from_ptr_range(range), &arr);
}

let mut arr = [1, 2, 3];
let range = arr.as_mut_ptr_range();
unsafe {
assert_eq!(slice::from_mut_ptr_range(range), &mut [1, 2, 3]);
}

let arr: [Vec<String>; 0] = [];
let range = arr.as_ptr_range();
unsafe {
assert_eq!(slice::from_ptr_range(range), &arr);
}
}
2 changes: 1 addition & 1 deletion src/doc/not_found.md
Original file line number Diff line number Diff line change
@@ -84,7 +84,7 @@ function on_submit(event) {
if (form['from'].value === 'duckduckgo') {
document.location.href = form.action + '?q=' + encodeURIComponent(q + ' site:doc.rust-lang.org');
} else if (form['from'].value === 'library') {
document.location.href = 'std/index.html?search=' + encodeURIComponent(q);
document.location.href = '/std/index.html?search=' + encodeURIComponent(q);
}
}

2 changes: 1 addition & 1 deletion src/doc/rustdoc/src/what-to-include.md
Original file line number Diff line number Diff line change
@@ -118,7 +118,7 @@ rustdoc --theme awesome.css src/lib.rs

Here is an example of a new theme, [Ayu].

[Ayu]: https://github.com/rust-lang/rust/blob/master/src/librustdoc/html/static/themes/ayu.css
[Ayu]: https://github.com/rust-lang/rust/blob/master/src/librustdoc/html/static/css/themes/ayu.css
[API Guidelines]: https://rust-lang.github.io/api-guidelines/documentation.html#rustdoc-does-not-show-unhelpful-implementation-details-c-hidden
[Documentation tests]: documentation-tests.md
[on this blog]: https://blog.guillaume-gomez.fr/articles/2016-09-16+Generating+doc+with+rustdoc+and+a+custom+theme
9 changes: 9 additions & 0 deletions src/test/ui/const-generics/generic_const_exprs/issue-90847.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,9 @@
// check-pass

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]
#![feature(adt_const_params)]

struct Foo<const A: [(); 0 + 0]> where [(); 0 + 0]: Sized;

fn main() {}