[PATCH 6/7] drm/panic: allow verbose boolean for clarity

[Alice Ryhl]

On Sat, Oct 12, 2024 at 9:53 AM Thomas Böhler <witcher at wiredspace.de> wrote:
>
> Clippy complains about a non-minimal boolean expression with
> `nonminimal_bool`:
>
>     error: this boolean expression can be simplified
>        --> drivers/gpu/drm/drm_panic_qr.rs:722:9
>         |
>     722 |         (x < 8 && y < 8) || (x < 8 && y >= end) || (x >= end && y < 8)
>         |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>         |
>         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool
>         = note: `-D clippy::nonminimal-bool` implied by `-D warnings`
>         = help: to override `-D warnings` add `#[allow(clippy::nonminimal_bool)]`
>     help: try
>         |
>     722 |         !(x >= 8 || y >= 8 && y < end) || (x >= end && y < 8)
>         |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     722 |         (y >= end || y < 8) && x < 8 || (x >= end && y < 8)
>         |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> While this can be useful in a lot of cases, it isn't here because the
> line expresses clearly what the intention is. Simplifying the expression
> means losing clarity, so opt-out of this lint for the offending line.
>
> Reported-by: Miguel Ojeda <ojeda at kernel.org>
> Closes: https://github.com/Rust-for-Linux/linux/issues/1123
> Signed-off-by: Thomas Böhler <witcher at wiredspace.de>
> ---
>  drivers/gpu/drm/drm_panic_qr.rs | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs
> index 58c46f366f76..226107c02679 100644
> --- a/drivers/gpu/drm/drm_panic_qr.rs
> +++ b/drivers/gpu/drm/drm_panic_qr.rs
> @@ -719,7 +719,8 @@ fn draw_finders(&mut self) {
>
>      fn is_finder(&self, x: u8, y: u8) -> bool {
>          let end = self.width - 8;
> -        (x < 8 && y < 8) || (x < 8 && y >= end) || (x >= end && y < 8)
> +        #[allow(clippy::nonminimal_bool)]
> +        return (x < 8 && y < 8) || (x < 8 && y >= end) || (x >= end && y < 8);

Surely introducing a return statement causes another clippy error?

You can do this:

#[allow(clippy::nonminimal_bool)]
{
    (x < 8 && y < 8) || (x < 8 && y >= end) || (x >= end && y < 8)
}

or just put the allow on the function.

Alice