Re: [PATCH 1/7] drm/panic: avoid reimplementing Iterator::find

From: Jocelyn Falempe
Date: Mon Oct 14 2024 - 04:45:58 EST


On 12/10/2024 09:52, Thomas Böhler wrote:
Rust's standard library's `std::iter::Iterator` trait provides a function
`find` that finds the first element that satisfies a predicate.
The function `Version::from_segments` is doing the same thing but is
implementing the same logic itself.
Clippy complains about this in the `manual_find` lint:

error: manual implementation of `Iterator::find`
--> drivers/gpu/drm/drm_panic_qr.rs:212:9
|
212 | / for v in (1..=40).map(|k| Version(k)) {
213 | | if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() {
214 | | return Some(v);
215 | | }
216 | | }
217 | | None
| |____________^ help: replace with an iterator: `(1..=40).map(|k| Version(k)).find(|&v| v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum())`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_find
= note: `-D clippy::manual-find` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::manual_find)]`

Use `Iterator::find` instead to make the intention clearer.

Thanks for this patch, and the whole series.

It's a nice cleanup.

Reviewed-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>

--

Jocelyn



Reported-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Closes: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@xxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_panic_qr.rs | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs
index 1ef56cb07dfb..76decf49e678 100644
--- a/drivers/gpu/drm/drm_panic_qr.rs
+++ b/drivers/gpu/drm/drm_panic_qr.rs
@@ -209,12 +209,9 @@
impl Version {
/// Returns the smallest QR version than can hold these segments.
fn from_segments(segments: &[&Segment<'_>]) -> Option<Version> {
- for v in (1..=40).map(|k| Version(k)) {
- if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() {
- return Some(v);
- }
- }
- None
+ (1..=40)
+ .map(Version)
+ .find(|&v| v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum())
}
fn width(&self) -> u8 {