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Refactor unsafe blocks; update TODO comments
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Update TODO comments which track adding safety comments to `unsafe`
blocks which are missing them. Previously, we used #61 to track these.
Now, we're using #429.
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@joshlf
joshlf committed Sep 29, 2023
1 parent b083f1f commit 812f63e
Showing 1 changed file with 34 additions and 28 deletions.
62 changes: 34 additions & 28 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -754,13 +754,15 @@ pub unsafe trait FromZeroes {
return Box::new(Self::new_zeroed());
}

// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
let ptr = unsafe { alloc::alloc::alloc_zeroed(layout).cast::<Self>() };
if ptr.is_null() {
alloc::alloc::handle_alloc_error(layout);
}
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe {
let ptr = alloc::alloc::alloc_zeroed(layout).cast::<Self>();
if ptr.is_null() {
alloc::alloc::handle_alloc_error(layout);
}
Box::from_raw(ptr)
}
}
Expand Down Expand Up @@ -810,21 +812,25 @@ pub unsafe trait FromZeroes {
let layout =
Layout::from_size_align(size, align).expect("total allocation size overflows `isize`");

// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
let ptr = if layout.size() != 0 {
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
let ptr = unsafe { alloc::alloc::alloc_zeroed(layout).cast::<Self>() };
if ptr.is_null() {
alloc::alloc::handle_alloc_error(layout);
}
ptr
} else {
// `Box<[T]>` does not allocate when `T` is zero-sized or when `len`
// is zero, but it does require a non-null dangling pointer for its
// allocation.
NonNull::<Self>::dangling().as_ptr()
};

// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe {
if layout.size() != 0 {
let ptr = alloc::alloc::alloc_zeroed(layout).cast::<Self>();
if ptr.is_null() {
alloc::alloc::handle_alloc_error(layout);
}
Box::from_raw(slice::from_raw_parts_mut(ptr, len))
} else {
// `Box<[T]>` does not allocate when `T` is zero-sized or when
// `len` is zero, but it does require a non-null dangling
// pointer for its allocation.
Box::from_raw(slice::from_raw_parts_mut(NonNull::<Self>::dangling().as_ptr(), len))
}
Box::from_raw(slice::from_raw_parts_mut(ptr, len))
}
}

Expand Down Expand Up @@ -2328,7 +2334,7 @@ where
/// and no mutable references to the same memory may be constructed during
/// `'a`.
unsafe fn deref_helper<'a>(&self) -> &'a T {
// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe {
&*self.0.as_ptr().cast::<T>()
Expand All @@ -2353,7 +2359,7 @@ where
/// and no other references - mutable or immutable - to the same memory may
/// be constructed during `'a`.
unsafe fn deref_mut_helper<'a>(&mut self) -> &'a mut T {
// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe {
&mut *self.0.as_mut_ptr().cast::<T>()
Expand Down Expand Up @@ -2382,7 +2388,7 @@ where
debug_assert_eq!(len % elem_size, 0);
len / elem_size
};
// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe {
slice::from_raw_parts(self.0.as_ptr().cast::<T>(), elems)
Expand Down Expand Up @@ -2412,7 +2418,7 @@ where
debug_assert_eq!(len % elem_size, 0);
len / elem_size
};
// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe {
slice::from_raw_parts_mut(self.0.as_mut_ptr().cast::<T>(), elems)
Expand Down Expand Up @@ -2754,7 +2760,7 @@ pub unsafe trait ByteSliceMut: ByteSlice + DerefMut {
}

impl<'a> sealed::ByteSliceSealed for &'a [u8] {}
// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe impl<'a> ByteSlice for &'a [u8] {
#[inline]
Expand All @@ -2764,7 +2770,7 @@ unsafe impl<'a> ByteSlice for &'a [u8] {
}

impl<'a> sealed::ByteSliceSealed for &'a mut [u8] {}
// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe impl<'a> ByteSlice for &'a mut [u8] {
#[inline]
Expand All @@ -2774,7 +2780,7 @@ unsafe impl<'a> ByteSlice for &'a mut [u8] {
}

impl<'a> sealed::ByteSliceSealed for cell::Ref<'a, [u8]> {}
// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe impl<'a> ByteSlice for cell::Ref<'a, [u8]> {
#[inline]
Expand All @@ -2784,7 +2790,7 @@ unsafe impl<'a> ByteSlice for cell::Ref<'a, [u8]> {
}

impl<'a> sealed::ByteSliceSealed for RefMut<'a, [u8]> {}
// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe impl<'a> ByteSlice for RefMut<'a, [u8]> {
#[inline]
Expand All @@ -2793,11 +2799,11 @@ unsafe impl<'a> ByteSlice for RefMut<'a, [u8]> {
}
}

// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe impl<'a> ByteSliceMut for &'a mut [u8] {}

// TODO(#61): Add a "SAFETY" comment and remove this `allow`.
// TODO(#429): Add a "SAFETY" comment and remove this `allow`.
#[allow(clippy::undocumented_unsafe_blocks)]
unsafe impl<'a> ByteSliceMut for RefMut<'a, [u8]> {}

Expand Down

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