Rustdoc reports non accessable items in blocks with `--document-private-items`, even with `#[doc(hidden)]`

[aDotInTheVoid]

#![allow(unused_macros, dead_code)]

#[doc(hidden)]
const _: () = {
    macro_rules! stry {
        () => {};
    }

    struct ShouldBeHidden;

    impl Bar for Foo {
        fn bar(&self) {
            struct SHouldAlsoBeHidden;
        }
    }
};

pub struct Foo;

pub trait Bar {
    fn bar(&self);
}

Produces with rustdoc +nightly src/lib.rs --document-private-items

which erroniously includes stry, ShouldBeHidden, and ShouldAlsoBeHidden.

Stable (1.66.0) gets this right

It's debatable what the semantics of --document-private-items should be for items in blocks without #[doc(hidden)] ¹, but here, we're just wrong.

We also can't just ignore all items in #[doc(hidden)] blocks, as this would break a load of users, eg serde.

Zulip Discussion

Probably, caused by #104889, cc @GuillaumeGomez

Footnotes

1. FWIW, I think they should still be hidden, as their not accessible outside the block. ↩

[GuillaumeGomez]

Tricky indeed. I see two ways of handling this problem:

1. Hide all items inside the block: if we pick this way, then how to unhide items which are declared into a block like this if you only want to hide the "block owner" and not the items in the block.
2. Keep the current behaviour and only hide items which have #[doc(hidden)] and their direct children, therefore excluding blocks since they're not children of the item.