diff options
| -rw-r--r-- | library/core/src/intrinsics/mod.rs | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/library/core/src/intrinsics/mod.rs b/library/core/src/intrinsics/mod.rs index 48b265fabc7..078f7552c87 100644 --- a/library/core/src/intrinsics/mod.rs +++ b/library/core/src/intrinsics/mod.rs @@ -1774,10 +1774,14 @@ pub fn ptr_mask<T>(ptr: *const T, mask: usize) -> *const T; /// a size of `count` * `size_of::<T>()` and an alignment of /// `min_align_of::<T>()` /// -/// The volatile parameter is set to `true`, so it will not be optimized out -/// unless size is equal to zero. -/// /// This intrinsic does not have a stable counterpart. +/// # Safety +/// +/// The safety requirements are consistent with [`copy_nonoverlapping`] +/// while the read and write behaviors are volatile, +/// which means it will not be optimized out unless `_count` or `size_of::<T>()` is equal to zero. +/// +/// [`copy_nonoverlapping`]: ptr::copy_nonoverlapping #[rustc_intrinsic] #[rustc_nounwind] pub unsafe fn volatile_copy_nonoverlapping_memory<T>(dst: *mut T, src: *const T, count: usize); @@ -1796,10 +1800,13 @@ pub unsafe fn volatile_copy_memory<T>(dst: *mut T, src: *const T, count: usize); /// size of `count * size_of::<T>()` and an alignment of /// `min_align_of::<T>()`. /// -/// The volatile parameter is set to `true`, so it will not be optimized out -/// unless size is equal to zero. -/// /// This intrinsic does not have a stable counterpart. +/// # Safety +/// +/// The safety requirements are consistent with [`write_bytes`] while the write behavior is volatile, +/// which means it will not be optimized out unless `_count` or `size_of::<T>()` is equal to zero. +/// +/// [`write_bytes`]: ptr::write_bytes #[rustc_intrinsic] #[rustc_nounwind] pub unsafe fn volatile_set_memory<T>(dst: *mut T, val: u8, count: usize); @@ -3341,8 +3348,18 @@ pub const fn is_val_statically_known<T: Copy>(_arg: T) -> bool { /// The stabilized form of this intrinsic is [`crate::mem::swap`]. /// /// # Safety +/// Behavior is undefined if any of the following conditions are violated: +/// +/// * Both `x` and `y` must be [valid] for both reads and writes. /// -/// `x` and `y` are readable and writable as `T`, and non-overlapping. +/// * Both `x` and `y` must be properly aligned. +/// +/// * The region of memory beginning at `x` must *not* overlap with the region of memory +/// beginning at `y`. +/// +/// * The memory pointed by `x` and `y` must both contain values of type `T`. +/// +/// [valid]: crate::ptr#safety #[rustc_nounwind] #[inline] #[rustc_intrinsic] |