Re: [RFC PATCH 1/1] v4l2-core: rewrite the VP9 library in Rust

From: Alice Ryhl
Date: Wed Feb 28 2024 - 09:13:56 EST


On Tue, Feb 27, 2024 at 10:56 PM Daniel Almeida
<daniel.almeida@xxxxxxxxxxxxx> wrote:
>
> +#[no_mangle]
> +pub extern "C" fn v4l2_vp9_seg_feat_enabled_rs(
> + feature_enabled: &mut u8,
> + feature: u32,
> + segid: u32,
> +) -> bool {
> + let feature_enabled = unsafe { core::slice::from_raw_parts_mut(feature_enabled, 8) };
> + let mask = 1 << feature;
> + feature_enabled[segid as usize] & mask != 0
> +}

This seems to be the only unsafe block. Impressive!

I recommend taking an `*mut u8` here instead of `&mut u8` if you're
going to use `slice::from_raw_parts_mut`. Or, if cbindgen allows it,
take an `&mut [u8; 8]` instead and eliminate the unsafe block.

Alice