Incorrect mixing of reexport and definition documentation of proc macros

[LukasKalbertodt]

The PR #62855 improved the situation about documenting proc macros. Thanks for that! However, I noticed a bug with it. I'm using rustc 1.39.0-nightly (6e19f3f38 2019-09-06).

Cargo.toml

[package]
name = "doc-bug"
version = "0.1.0"
authors = ["me"]
edition = "2018"

[dependencies]
macros = { path = "macros" }

src/lib.rs

/// Reexport `foo`.
pub use macros::foo;

/// Reexport `Bar`.
pub use macros::Bar;

/// Reexport `Baz`.
pub use macros::Baz;

macros/Cargo.toml

[package]
name = "macros"
version = "0.1.0"
authors = ["me"]
edition = "2018"

[lib]
proc-macro = true

macros/src/lib.rs

extern crate proc_macro;

use proc_macro::TokenStream;

/// Definition `foo`.
#[proc_macro]
pub fn foo(input: TokenStream) -> TokenStream {
    input
}

/// Definition `Bar`.
#[proc_macro_derive(Bar)]
pub fn bar(input: TokenStream) -> TokenStream {
    input
}

/// Definition `Baz`.
#[proc_macro_derive(Baz)]
pub fn baz(input: TokenStream) -> TokenStream {
    input
}

Running cargo doc results in this:

Looks like a simple typo or off-by-one or something like that bug. When using only proc_macro and not proc_macro_derives, everything looks good to me.

CC @Aaron1011

[LukasKalbertodt]

Oh, and also, running cargo doc prints:

   Compiling macros v0.1.0 (/home/lukas/dev/doc-bug/macros)
 Documenting macros v0.1.0 (/home/lukas/dev/doc-bug/macros)
warning: Trying to document proc macro crate without passing '--crate-type proc-macro to rustdoc
  |
  = warning: The generated documentation may be incorrect

 Documenting doc-bug v0.1.0 (/home/lukas/dev/doc-bug)
    Finished dev [unoptimized + debuginfo] target(s) in 1.71s

Not sure if this warning is expected there. And not sure if related to this bug.

[Aaron1011]

This is a consequence of the fact that rust-lang/cargo#7159 has not yet been merged. Once it gets merged, and rust updates its Cargo submodule, this issue should go away.

[Aaron1011]

@LukasKalbertodt: It turns out that this issue was unrelated. I've opened a PR to fix it.

[LukasKalbertodt]

@Aaron1011 I see. Thanks for your work on this :)