Function lean_alloc_ctor_memory

src/lib.rs:189–220

(sz: c_uint)

#[inline]
pub unsafe fn lean_alloc_ctor_memory(sz: c_uint) -> *mut lean_object {
    if LEAN_SMALL_ALLOCATOR {
        let sz1 = lean_align(sz as usize, LEAN_OBJECT_SIZE_DELTA) as c_uint;
        let slot_idx = lean_get_slot_idx(sz1);
        debug_assert!(sz1 <= LEAN_MAX_SMALL_OBJECT_SIZE);
        let r = lean_alloc_small(sz1, slot_idx);
        if sz1 > sz {
            //TODO: "two structurally equal objects"?
            /* Initialize last word.
            In our runtime `lean_object_byte_size` is always
            a multiple of the machine word size for constructors.

            By setting the last word to 0, we make sure the sharing
            maximizer procedures at `maxsharing.cpp` and `compact.cpp` are
            not affected by uninitialized data at the (sz1 - sz) last bytes.
            Otherwise, we may mistakenly assume to structurally equal
            objects are not identical because of this uninitialized memory. */
            let end = (r as *mut u8).add(sz1 as usize) as *mut usize;
            *end.sub(1) = 0;
        }
        r as *mut lean_object
    } else if LEAN_MIMALLOC {
        let sz1 = lean_align(sz as usize, LEAN_OBJECT_SIZE_DELTA) as c_uint;
        let r = lean_alloc_small_object(sz1);
        if sz1 > sz {
            *r.byte_add(sz1 as usize).cast::<usize>().sub(1) = 0;
        }
        r
    } else {
        lean_alloc_small_object(sz)
    }
}

#[inline(always)]
pub unsafe fn lean_small_object_size(o: *mut lean_object) -> c_uint {