rust-lang
Custom derive attribute stripping is insufficient
In
#[derive(Derive)]
#[cfg_attr(never, derive(Clone))]
struct S {
#[cfg(never)]
invisible_field: u8,
#[cfg(not(never))]
visible_field: u8,
}
The Derive macro should be passed the token stream corresponding to
struct S {
#[cfg(not(never))]
visible_field: u8,
}
Currently, we pass
#[cfg_attr(never, derive(Clone))]
struct S {
#[cfg(never)]
invisible_field: u8,
#[cfg(not(never))]
visible_field: u8,
}
Since we have to evalutate cfgs to do this correctly, I propose moving the remove_derive_attrs code to hir_expand.
Also, we should only be removing #[derive] attributes that come before the currently expanded derive macro, at least when https://github.com/rust-lang/rust/pull/84023 lands (see its tests)
Another relevant upstream PR: https://github.com/rust-lang/rust/pull/84110
Hello! Our team is struggling because of this bug. Do you plan to fix this? It's open for 2 years already.
This got worse for me about 3 or 4 weeks ago, specifically with #[cfg(target_os = ...)] fields. Maybe a regression? It's unfortunately making it impossible to see real errors in VSCode.
Same (or very similar) problem here with serde derive, it causes no-such-field error , it's caused by field, which is behind inactive feature, line 164,165. If I enable the feature in rust-analyzer settings that it's OK. I'm almost sure that it did work some time ago - few month, so wondering why this old issue demostrated just now.
