Fix ICE in Definitions::create_def

[GoldsteinE]

Debug implementation for LocalDefId uses global Definitions. Normally it’s ok, but we can’t do it while holding a mutable reference to Definitions, since it causes ICE or deadlock (depending on whether parallel_compiler is enabled).

This PR effectively copies the Debug implementation into the problematic method. I don’t particularly love this solution (since it creates code duplication), but I don’t see any other options.

This issue was discovered when running rustdoc with RUSTDOC_LOG=trace on the following file:

pub struct SomeStruct;

fn asdf() {
    impl SomeStruct {
        pub fn qwop(&self) {
            println!("hidden function");
        }
    }
}

I’m not sure how to create a test for this behavior.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @lcnr (or someone else) soon.

Please see the contribution instructions for more information.

[lcnr]

thanks 👍

@bors r+ rollup squash

[bors]

📌 Commit b85c5f0417585cf77d8613a7d6d2e691da328aa5 has been approved by lcnr

It is now in the queue for this repository.

[klensy]

thanks 👍

@bors r+ rollup squash

Can't find exact PR, but recently r+ squash was tried and it didn't worked in rollup.

[GoldsteinE]

I manually squashed the commits, could someone re-approve this?

[lcnr]

@bors r+ rollup

[bors]

📌 Commit d9f28b7 has been approved by lcnr

It is now in the queue for this repository.