dnrops
/
rust
mirror of https://github.com/rust-lang/rust.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Rollup merge of #120424 - RalfJung:raw-ptr-meta, r=Nilstrieb 

raw pointer metadata API: data address -> data pointer

A pointer consists of [more than just an address](https://github.com/rust-lang/rfcs/pull/3559), so let's not equate "pointer" and "address" in these docs.
This commit is contained in:
Guillaume Gomez 2024-01-30 11:19:16 +01:00 committed by GitHub
parent 8ab372d61a b4e1c569fe
commit 6e046fef29
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
7 changed files with 19 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
library/core/src/ptr/const_ptr.rs
View File

@ -285,7 +285,7 @@ impl<T: ?Sized> *const T {
self.with_addr(f(self.addr()))
}
/// Decompose a (possibly wide) pointer into its address and metadata components.
/// Decompose a (possibly wide) pointer into its data pointer and metadata components.
///
/// The pointer can be later reconstructed with [`from_raw_parts`].
#[unstable(feature = "ptr_metadata", issue = "81513")]

16
library/core/src/ptr/metadata.rs
View File

@ -39,13 +39,13 @@ use crate::hash::{Hash, Hasher};
///
/// # Usage
///
/// Raw pointers can be decomposed into the data address and metadata components
/// Raw pointers can be decomposed into the data pointer and metadata components
/// with their [`to_raw_parts`] method.
///
/// Alternatively, metadata alone can be extracted with the [`metadata`] function.
/// A reference can be passed to [`metadata`] and implicitly coerced.
///
/// A (possibly-wide) pointer can be put back together from its address and metadata
/// A (possibly-wide) pointer can be put back together from its data pointer and metadata
/// with [`from_raw_parts`] or [`from_raw_parts_mut`].
///
/// [`to_raw_parts`]: *const::to_raw_parts
@ -98,7 +98,7 @@ pub const fn metadata<T: ?Sized>(ptr: *const T) -> <T as Pointee>::Metadata {
unsafe { PtrRepr { const_ptr: ptr }.components.metadata }
}
/// Forms a (possibly-wide) raw pointer from a data address and metadata.
/// Forms a (possibly-wide) raw pointer from a data pointer and metadata.
///
/// This function is safe but the returned pointer is not necessarily safe to dereference.
/// For slices, see the documentation of [`slice::from_raw_parts`] for safety requirements.
@ -109,13 +109,13 @@ pub const fn metadata<T: ?Sized>(ptr: *const T) -> <T as Pointee>::Metadata {
#[rustc_const_unstable(feature = "ptr_metadata", issue = "81513")]
#[inline]
pub const fn from_raw_parts<T: ?Sized>(
data_address: *const (),
data_pointer: *const (),
metadata: <T as Pointee>::Metadata,
) -> *const T {
// SAFETY: Accessing the value from the `PtrRepr` union is safe since *const T
// and PtrComponents<T> have the same memory layouts. Only std can make this
// guarantee.
unsafe { PtrRepr { components: PtrComponents { data_address, metadata } }.const_ptr }
unsafe { PtrRepr { components: PtrComponents { data_pointer, metadata } }.const_ptr }
}
/// Performs the same functionality as [`from_raw_parts`], except that a
@ -126,13 +126,13 @@ pub const fn from_raw_parts<T: ?Sized>(
#[rustc_const_unstable(feature = "ptr_metadata", issue = "81513")]
#[inline]
pub const fn from_raw_parts_mut<T: ?Sized>(
data_address: *mut (),
data_pointer: *mut (),
metadata: <T as Pointee>::Metadata,
) -> *mut T {
// SAFETY: Accessing the value from the `PtrRepr` union is safe since *const T
// and PtrComponents<T> have the same memory layouts. Only std can make this
// guarantee.
unsafe { PtrRepr { components: PtrComponents { data_address, metadata } }.mut_ptr }
unsafe { PtrRepr { components: PtrComponents { data_pointer, metadata } }.mut_ptr }
}
#[repr(C)]
@ -144,7 +144,7 @@ union PtrRepr<T: ?Sized> {
#[repr(C)]
struct PtrComponents<T: ?Sized> {
data_address: *const (),
data_pointer: *const (),
metadata: <T as Pointee>::Metadata,
}

2
library/core/src/ptr/mut_ptr.rs
View File

@ -292,7 +292,7 @@ impl<T: ?Sized> *mut T {
self.with_addr(f(self.addr()))
}
/// Decompose a (possibly wide) pointer into its address and metadata components.
/// Decompose a (possibly wide) pointer into its data pointer and metadata components.
///
/// The pointer can be later reconstructed with [`from_raw_parts_mut`].
#[unstable(feature = "ptr_metadata", issue = "81513")]

8
library/core/src/ptr/non_null.rs
View File

@ -259,16 +259,16 @@ impl<T: ?Sized> NonNull<T> {
#[rustc_const_unstable(feature = "ptr_metadata", issue = "81513")]
#[inline]
pub const fn from_raw_parts(
data_address: NonNull<()>,
data_pointer: NonNull<()>,
metadata: <T as super::Pointee>::Metadata,
) -> NonNull<T> {
// SAFETY: The result of `ptr::from::raw_parts_mut` is non-null because `data_address` is.
// SAFETY: The result of `ptr::from::raw_parts_mut` is non-null because `data_pointer` is.
unsafe {
NonNull::new_unchecked(super::from_raw_parts_mut(data_address.as_ptr(), metadata))
NonNull::new_unchecked(super::from_raw_parts_mut(data_pointer.as_ptr(), metadata))
}
}
/// Decompose a (possibly wide) pointer into its address and metadata components.
/// Decompose a (possibly wide) pointer into its data pointer and metadata components.
///
/// The pointer can be later reconstructed with [`NonNull::from_raw_parts`].
#[unstable(feature = "ptr_metadata", issue = "81513")]

4
tests/mir-opt/pre-codegen/slice_index.slice_get_unchecked_mut_range.PreCodegen.after.panic-abort.mir
View File

@ -42,7 +42,7 @@ fn slice_get_unchecked_mut_range(_1: &mut [u32], _2: std::ops::Range<usize>) ->
debug self => _8;
}
scope 15 (inlined std::ptr::from_raw_parts_mut::<[u32]>) {
debug data_address => _9;
debug data_pointer => _9;
debug metadata => _6;
let mut _10: *const ();
let mut _11: std::ptr::metadata::PtrComponents<[u32]>;
@ -90,7 +90,7 @@ fn slice_get_unchecked_mut_range(_1: &mut [u32], _2: std::ops::Range<usize>) ->
StorageLive(_11);
StorageLive(_10);
_10 = _9 as *const () (PointerCoercion(MutToConstPointer));
_11 = std::ptr::metadata::PtrComponents::<[u32]> { data_address: move _10, metadata: _6 };
_11 = std::ptr::metadata::PtrComponents::<[u32]> { data_pointer: move _10, metadata: _6 };
StorageDead(_10);
_12 = std::ptr::metadata::PtrRepr::<[u32]> { const_ptr: move _11 };
StorageDead(_11);

4
tests/mir-opt/pre-codegen/slice_index.slice_get_unchecked_mut_range.PreCodegen.after.panic-unwind.mir
View File

@ -42,7 +42,7 @@ fn slice_get_unchecked_mut_range(_1: &mut [u32], _2: std::ops::Range<usize>) ->
debug self => _8;
}
scope 15 (inlined std::ptr::from_raw_parts_mut::<[u32]>) {
debug data_address => _9;
debug data_pointer => _9;
debug metadata => _6;
let mut _10: *const ();
let mut _11: std::ptr::metadata::PtrComponents<[u32]>;
@ -90,7 +90,7 @@ fn slice_get_unchecked_mut_range(_1: &mut [u32], _2: std::ops::Range<usize>) ->
StorageLive(_11);
StorageLive(_10);
_10 = _9 as *const () (PointerCoercion(MutToConstPointer));
_11 = std::ptr::metadata::PtrComponents::<[u32]> { data_address: move _10, metadata: _6 };
_11 = std::ptr::metadata::PtrComponents::<[u32]> { data_pointer: move _10, metadata: _6 };
StorageDead(_10);
_12 = std::ptr::metadata::PtrRepr::<[u32]> { const_ptr: move _11 };
StorageDead(_11);

2
tests/ui/union/issue-81199.rs
View File

@ -9,7 +9,7 @@ union PtrRepr<T: ?Sized> {
#[repr(C)]
struct PtrComponents<T: Pointee + ?Sized> {
data_address: *const (),
data_pointer: *const (),
metadata: <T as Pointee>::Metadata,
}