rustdoc: Referencing methods on extern_types does not resolve

[crumblingstatue]

I tried this code:

#![feature(extern_types)]

extern {
    /// The extern type Foo.
    pub type Foo;
}

/// The struct Bar.
pub struct Bar;

impl Foo {
    /// Does stuff
    pub fn do_it(&self) {

    }
}

impl Bar {
    /// This does stuff too
    pub fn do_it(&self) {

    }
}

/// See also [Foo::do_it]
pub fn foo() {

}

/// See also [Bar::do_it]
pub fn bar() {

}

I expected to see this happen: Both Foo::do_it and Bar::do_it resolve.

Instead, this happened: Only Bar::do_it resolves.

warning: unresolved link to `Foo::do_it`
  --> src/lib.rs:25:15
   |
25 | /// See also [Foo::do_it]
   |               ^^^^^^^^^^ the foreign type `Foo` has no associated item named `do_it`

Meta

rustc --version --verbose:

rustc 1.49.0-nightly (ffa2e7ae8 2020-10-24)
binary: rustc
commit-hash: ffa2e7ae8fbf9badc035740db949b9dae271c29f
commit-date: 2020-10-24
host: x86_64-unknown-linux-gnu
release: 1.49.0-nightly
LLVM version: 11.0

[jyn514]

Mentoring instructions: in

rust/src/librustdoc/passes/collect_intra_doc_links.rs

Line 436 in b385598

Res::Def(DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::TyAlias, did) => {

instead of checking specific DefKinds one at a time, look to see if they're in the TypeNS. You can check with kind.ns() == Some(TypeNS).

[lochsh]

I'll have a crack at this if no one is working on it -- I'm a first-time contributor but the mentoring instructions look like enough to be getting on with 👍

[jyn514]

@lochsh awesome! There's instructions for getting started on https://rustc-dev-guide.rust-lang.org/, and you can ask in the Rustdoc Discord channel if you need help.