Skip to content

add missing provenance APIs on NonNull #135242

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.

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

Merged
merged 1 commit into from
Jan 9, 2025
Merged
Changes from all commits
Commits
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
48 changes: 45 additions & 3 deletions library/core/src/ptr/non_null.rs
Original file line number Diff line number Diff line change
Expand Up @@ -85,6 +85,20 @@ impl<T: ?Sized> !Send for NonNull<T> {}
impl<T: ?Sized> !Sync for NonNull<T> {}

impl<T: Sized> NonNull<T> {
/// Creates a pointer with the given address and no [provenance][crate::ptr#provenance].
///
/// For more details, see the equivalent method on a raw pointer, [`ptr::without_provenance_mut`].
///
/// This is a [Strict Provenance][crate::ptr#strict-provenance] API.
#[unstable(feature = "nonnull_provenance", issue = "135243")]
pub const fn without_provenance(addr: NonZero<usize>) -> Self {
// SAFETY: we know `addr` is non-zero.
unsafe {
let ptr = crate::ptr::without_provenance_mut(addr.get());
NonNull::new_unchecked(ptr)
}
}

/// Creates a new `NonNull` that is dangling, but well-aligned.
///
/// This is useful for initializing types which lazily allocate, like
Expand Down Expand Up @@ -116,6 +130,21 @@ impl<T: Sized> NonNull<T> {
}
}

/// Converts an address back to a mutable pointer, picking up some previously 'exposed'
/// [provenance][crate::ptr#provenance].
///
/// For more details, see the equivalent method on a raw pointer, [`ptr::with_exposed_provenance_mut`].
///
/// This is an [Exposed Provenance][crate::ptr#exposed-provenance] API.
#[unstable(feature = "nonnull_provenance", issue = "135243")]
pub fn with_exposed_provenance(addr: NonZero<usize>) -> Self {
// SAFETY: we know `addr` is non-zero.
unsafe {
let ptr = crate::ptr::with_exposed_provenance_mut(addr.get());
NonNull::new_unchecked(ptr)
}
}

/// Returns a shared references to the value. In contrast to [`as_ref`], this does not require
/// that the value has to be initialized.
///
Expand Down Expand Up @@ -282,7 +311,7 @@ impl<T: ?Sized> NonNull<T> {

/// Gets the "address" portion of the pointer.
///
/// For more details see the equivalent method on a raw pointer, [`pointer::addr`].
/// For more details, see the equivalent method on a raw pointer, [`pointer::addr`].
///
/// This is a [Strict Provenance][crate::ptr#strict-provenance] API.
#[must_use]
Expand All @@ -294,10 +323,23 @@ impl<T: ?Sized> NonNull<T> {
unsafe { NonZero::new_unchecked(self.as_ptr().addr()) }
}

/// Exposes the ["provenance"][crate::ptr#provenance] part of the pointer for future use in
/// [`with_exposed_provenance`][NonNull::with_exposed_provenance] and returns the "address" portion.
///
/// For more details, see the equivalent method on a raw pointer, [`pointer::expose_provenance`].
///
/// This is an [Exposed Provenance][crate::ptr#exposed-provenance] API.
#[unstable(feature = "nonnull_provenance", issue = "135243")]
pub fn expose_provenance(self) -> NonZero<usize> {
// SAFETY: The pointer is guaranteed by the type to be non-null,
// meaning that the address will be non-zero.
unsafe { NonZero::new_unchecked(self.as_ptr().expose_provenance()) }
}

/// Creates a new pointer with the given address and the [provenance][crate::ptr#provenance] of
/// `self`.
///
/// For more details see the equivalent method on a raw pointer, [`pointer::with_addr`].
/// For more details, see the equivalent method on a raw pointer, [`pointer::with_addr`].
///
/// This is a [Strict Provenance][crate::ptr#strict-provenance] API.
#[must_use]
Expand All @@ -311,7 +353,7 @@ impl<T: ?Sized> NonNull<T> {
/// Creates a new pointer by mapping `self`'s address to a new one, preserving the
/// [provenance][crate::ptr#provenance] of `self`.
///
/// For more details see the equivalent method on a raw pointer, [`pointer::map_addr`].
/// For more details, see the equivalent method on a raw pointer, [`pointer::map_addr`].
///
/// This is a [Strict Provenance][crate::ptr#strict-provenance] API.
#[must_use]
Expand Down
Loading