Possible problems involving clippy::shadow_reuse and auto-generated code

[c410-f3r]

Description

According to dtolnay/quote#232 (comment), clippy::shadow_reuse shouldn't be triggered but I am personally not aware of this intended limitation. Any thoughts?

Version

Latest 1.65 beta

Additional Labels

No response

[Alexendoo]

A fix for this case would be to check pat.span.from_expansion() in addition to the current ident.span.from_expansion() check

It wouldn't be intended for this to lint, macro span interactions are just non obvious

[c410-f3r]

Closing due to the lack of activity.

[Alexendoo]

The issue isn't fixed

[c410-f3r]

I am house-keeping my dashboard closing inactive issues that will probably take some time to resolve.

For this use-case specifically, I guess I can try to solve the problem.

[lochetti]

I am trying to take a look at this issue. Although, this would be my first contribution here.

Not linting the code if pat.span.from_expansion() does solve the specific issue mentioned for the quote crate, but I have one doubt: Which is the best way to increment the tests in order to add this use case? I am really not sure how to do that.

Thanks for the patience in helping a new contributor wannabe!

[c410-f3r]

To solve the issue, I think shadow_reuse should also check clippy_utils::is_from_proc_macro along side the already included ident.span.from_expansion(). See #10203 (comment).

In regards to test addition or how to test this issue specifically, I really have no clue because https://github.com/rust-lang/rust-clippy/pull/10203/files#diff-98b6b061d5b311aae09fd482c612aab5544d55b9c0da67438d79ef0fe181d526R129-R159 didn't help.

Perhaps one of the Clippy members can help you? @Alexendoo @Jarcho @xFrednet

EDIT: Oops, if pat.span.from_expansion() indeed solved the problem then forget about my clippy_utils::is_from_proc_macro suggestion.

[Alexendoo]

You can add a test along the lines of

macro_rules! reuse {
    ($v:ident) => {
        let $v = $v + 1;
    }
}

let x = 1;
reuse!(x);