Skip to content

Commit

Permalink
Fix a couple of iterator ZST handling oversights
Browse files Browse the repository at this point in the history
  • Loading branch information
@slightlyoutofphase
slightlyoutofphase committed Jan 7, 2022
1 parent b90915f commit 342e907
Show file tree
Hide file tree
Showing 3 changed files with 116 additions and 19 deletions.
17 changes: 9 additions & 8 deletions src/iterators.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -170,7 +170,7 @@ impl<'a, T: 'a, const N: usize> Iterator for StaticVecIterConst<'a, T, N> {
// Safety: see the comments for the implementation of this function in
// 'core/slice/iter/macros.rs`, as they're equally applicable to us here.
match size_of::<T>() {
0 => &*zst_ptr_add(self.start, idx),
0 => &*((self.start as usize + idx) as *const T),
_ => &*self.start.add(idx),
}
}
Expand Down Expand Up @@ -368,7 +368,7 @@ impl<'a, T: 'a, const N: usize> Iterator for StaticVecIterMut<'a, T, N> {
// Safety: see the comments for the implementation of this function in
// 'core/slice/iter/macros.rs`, as they're equally applicable to us here.
match size_of::<T>() {
0 => &mut *zst_ptr_add_mut(self.start, idx),
0 => &mut *((self.start as usize + idx) as *mut T),
_ => &mut *self.start.add(idx),
}
}
Expand Down Expand Up @@ -655,13 +655,14 @@ impl<T: Clone, const N: usize> Clone for StaticVecIntoIter<T, N> {
data: {
let mut data = MaybeUninit::<[T; N]>::uninit();
let new_data_ptr = data.as_mut_ptr() as *mut T;
// Guaranteed safe assumption in this context.
unsafe { assume(!new_data_ptr.is_null()) };
let self_data_ptr = self.data.as_ptr() as *const T;
// Guaranteed safe assumption in this context.
unsafe { assume(!self_data_ptr.is_null()) };
for i in self.start..self.end {
unsafe { new_data_ptr.add(i).write((&*self_data_ptr.add(i)).clone()) };
unsafe {
// These are guaranteed safe assumptions in this context.
assume(!new_data_ptr.is_null());
assume(!self_data_ptr.is_null());
for i in self.start..self.end {
new_data_ptr.add(i).write((&*self_data_ptr.add(i)).clone());
}
}
data
},
Expand Down
5 changes: 4 additions & 1 deletion src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1991,7 +1991,10 @@ impl<T, const N: usize> StaticVec<T, N> {
unsafe {
// Set the length to `start` to avoid memory issues if anything goes wrong with the Drain.
self.set_len(start);
let start_ptr = self.ptr_at_unchecked(start);
let start_ptr = match size_of::<T>() {
0 => zst_ptr_add(self.as_ptr(), start),
_ => self.ptr_at_unchecked(start),
};
// `start_ptr` will never be null, so this is a safe assumption to give to
// the optimizer.
assume(!start_ptr.is_null());
Expand Down
113 changes: 103 additions & 10 deletions test/test_staticvec.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -488,10 +488,18 @@ fn drain_iter() {
ZST {},
ZST {},
ZST {},
ZST {}
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
];
v5.drain_iter(0..4);
assert_eq!(&v5[..], &[ZST {}, ZST {}, ZST {}, ZST {}]);
assert_eq!(v5.drain_iter(6..12).len(), 6);
assert_eq!(v5.len(), 10);
assert_eq!(
staticvec![1, 2, 3, 4]
.drain_iter(1..3)
Expand All @@ -515,6 +523,11 @@ fn drain_filter() {
let odds = numbers;
assert_eq!(evens, [2, 4, 6, 8, 14]);
assert_eq!(odds, [1, 3, 5, 9, 11, 13, 15]);
let mut zsts1 = staticvec![ZST {}, ZST {}, ZST {}, ZST {}];
let full = zsts1.drain_filter(|x| *x == ZST {});
let empty = zsts1;
assert_eq!(full, [ZST {}, ZST {}, ZST {}, ZST {}]);
assert_eq!(empty, []);
let mut empty: StaticVec<i32, 12> = StaticVec::from([]);
assert_eq!(empty.drain_filter(|x| *x == 0), []);
let mut structs: StaticVec<Box<Struct>, 4> = staticvec![
Expand Down Expand Up @@ -1025,10 +1038,27 @@ fn iter() {
assert_eq!(iter2.next(), Some((&ZST {}, &ZST {})));
assert_eq!(iter2.next(), Some((&ZST {}, &ZST {})));
assert_eq!(iter2.next(), None);
let a5 = staticvec![ZST {}, ZST {}, ZST {}, ZST {}];
let a5 = staticvec![
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {}
];
let mut iter3 = a5.iter();
unsafe {
assert_eq!(iter3.__iterator_get_unchecked(2), &ZST {});
assert_eq!(iter3.__iterator_get_unchecked(13), &ZST {});
}
}

Expand Down Expand Up @@ -1239,10 +1269,27 @@ fn iter_mut() {
a1.concat_clone(&a2),
staticvec![box 2, box 3, box 4, box 5, box 6, box 7]
);
let mut a3 = staticvec![ZST {}, ZST {}, ZST {}, ZST {}];
let mut a3 = staticvec![
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {},
ZST {}
];
let mut iter2 = a3.iter_mut();
unsafe {
assert_eq!(iter2.__iterator_get_unchecked(2), &ZST {});
assert_eq!(iter2.__iterator_get_unchecked(13), &ZST {});
}
}

Expand Down Expand Up @@ -1460,13 +1507,59 @@ fn into_iter() {
let iter3 = iter2.clone();
assert_eq!(iter2.as_slice(), iter3.as_slice());
// Needs to work properly with ZSTs too of course.
let a5 = staticvec![CloneableZST, CloneableZST, CloneableZST, CloneableZST, CloneableZST, CloneableZST];
let a5 = staticvec![
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST
];
let mut iter4 = a5.into_iter();
iter4.nth(0);
iter4.next_back();
iter4.next();
let iter5 = iter4.clone();
assert_eq!(iter4.as_slice(), iter5.as_slice());
let mut iter5 = iter4.clone();
assert_eq!(iter4.as_slice(), iter5.as_slice());
for x in iter4.as_slice().iter() {
assert_eq!(x, &CloneableZST);
}
for y in iter5.as_mut_slice().iter_mut() {
assert_eq!(y, &mut CloneableZST);
}
let mut i = 0;
for x in staticvec![
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST,
CloneableZST
] {
assert_eq!(x, CloneableZST);
i += 1;
}
assert_eq!(i, 16);
}

#[test]
Expand Down

0 comments on commit 342e907

Please sign in to comment.