Maybe incorrect usage of proc-macro-crate in some proc macros

[indirection42]

There are bunch of codes in the codebase use the @bkchr 's proc-macro-crate to generate crate access like this:

use proc_macro_crate::{crate_name, FoundCrate};
...
match crate_name(def_crate) {
     Ok(FoundCrate::Itself) => Ident::new(def_crate.replace('-', "_"), Span::call_site())
     Ok(FoundCrate::Name(name) => Ident::new(&name, Span::call_site()),
     Err(e) => return 	Error::new(Span::call_site(), e.to_compile_error());
}
...

However, the Itself branch seems incorrect. We cannot directly refer def_crate in def_crate itself, see also rust-lang/rust#54363.
I think the correct usage is Ok(FoundCrate::Itself) => Ident::new("crate", Span::call_site()).

[bkchr]

Do you have any issues or what is the problem? Using crate does not work for integration tests for example.

[indirection42]

Since there are no usages of referring def_crate in def_crate in this repo except integration test (actually each integration test is compiled as a separate crate), this issue doesn't show off.
I wrote an example to demonstrate this issue.

https://github.com/indirection42/proc-macro-crate-example/blob/465ad32f5f6dbb11d1d36caa81462c2daadd1265/adder/procedural/src/lib.rs#L24-L30
If we use quote!(adder::submod) in FoundCrate::Itself branch, we cannot use the macro in adder's unit test.
https://github.com/indirection42/proc-macro-crate-example/blob/465ad32f5f6dbb11d1d36caa81462c2daadd1265/adder/src/lib.rs#L11

[bkchr]

Everything is compiling in this repo. I have no idea why exactly you opened this issue. I mean did something not work for you? You are just confused that it works?

BTW, you can write in your lib.rs:

extern crate self as whatever;

Then you can refer to your own crate in your own crate using whatever.

Given that this is more an issue for the proc-macro-crate issue tracker and there is not really an issue, I'm going to close this.

[indirection42]

I mean it's a potential bug. Considering this pattern is used often in polkadot-sdk, if someone is referring the pattern used in this repo, and he/she tests the some-crate-proc-macro in a unit test within the some-crate, then he/she will get confused why it won't compile.