Open IceTDrinker opened 1 month ago
dead_code
comes from rustc, does cargo +nightly-2024-07-18 check --all-targets --features serde
exhibit the same behaviour?
checking
warnings are popping up as well, so wrong repo I guess ? is there a way to transfer this issue to rustc ?
This will need a smaller reproduction. Any chance you could try extracting the relevant code out?
I don't really have time currently I'm afraid :/ otherwise I could offer an automated bisect on that
No worries, somebody will chase it down at some point :)
Regression in https://github.com/rust-lang-ci/rust/commit/4cfe57a6518913330a52c45021aa3ab26ac53558 The PR introducing the regression in this rollup is #122382: Detect unused structs which implement private traits
I will have a look
There are also similar older versions of this issue, like the following (playground). That's been warning since 1.57:
use std::mem;
#[repr(transparent)]
pub struct X<T: ?Sized> {
pub inner: T,
}
pub struct Y {}
impl Drop for Y {
fn drop(&mut self) {
type A = Vec<u8>;
const _: () = assert!(mem::size_of::<X<A>>() == mem::size_of::<A>());
}
}
Note that this is not a reduction of the OP and not necessarily a duplicate, but was encountered in real world code.
@rustbot claim
Summary
Some type is flagged by Clippy as never used, though it is used in an internal trait implementation
Lint Name
dead_code
Reproducer
I tried this code:
clone https://github.com/zama-ai/concrete-fft/commit/aeb75d4b7c5cc6b3031bf5b9f4730961f3132fe5
run pre commit checks, runs a clippy check: make pcc
faulty clippy invokation:
I saw this happen:
I expected to see this happen:
No warning/error for these types as they are used in e.g. https://github.com/zama-ai/concrete-fft/blob/aeb75d4b7c5cc6b3031bf5b9f4730961f3132fe5/src/dit16.rs#L823
Version
Additional Labels
No response