Having custom core module in scope breakes builtin derive(Clone) macro

[Veetaha]

Reproduction code

mod core {}

#[derive(Clone)]
struct Foo;

fn main() {
    let _ = Foo.clone();
    //          ^^^^^ this method call is not resolved according to rust-analyzer
}

Demo

Other reproductions

The real use case where this happened is in a reexport in our library that wraps the rusoto AWS SDK:

pub use rusoto_core as core;

So reexport of modules as core also suffer from the same problem.

Meta

rust-analyzer version: rust-analyzer version: 0.3.1277-standalone
rustc version: rustc 1.64.0 (a55dd71d5 2022-09-19)

[jonas-schievink]

Perhaps this should produce ::core instead of a plain core?

rust-analyzer/crates/hir-expand/src/builtin_derive_macro.rs

Line 154 in 599142c

quote! { core }

[lnicola]

Yup, this works, but then tt.token_trees[0] two lines below will point to the :: token instead. I couldn't figure out if quote! supports a Subtree or we need some other way of splicing the whole thing in the expansions.

[lnicola]

Fixed by #16308.