[rustdoc] Calculate span information on demand instead of storing it ahead of time
This brings `size_of<clean::types::Span>()` down from over 100 bytes (!!) to only 12, the same as rustc. It brings `Item` down even more, from `784` to `680`.
~~TODO: I need to figure out how to do this for the JSON backend too. That uses `From` impls everywhere, which don't allow passing in the `Session` as an argument. `@P1n3appl3,` `@tmandry,` maybe one of you have ideas?~~ Figured it out, fortunately only two functions needed to be changed. I like the `convert_x()` format better than `From` everywhere but I'm open to feedback.
Helps with #79103
Apply `doc(cfg)` from parent items while collecting trait impls
Because trait impls bypass the standard `clean` hierarchy they do not participate in the `propagate_doc_cfg` pass, so instead we need to pre-collect all possible `doc(cfg)` attributes that will apply to them when cleaning.
fixes#79201
- Take `String` instead of `Symbol` - this avoids having to intern then
immediately stringify the existing string.
- Remove unused `get_stability` and `get_deprecation`
- Remove unused `attrs` field from `primitives`
Because trait impls bypass the standard `clean` hierarchy they do not
participate in the `propagate_doc_cfg` pass, so instead we need to
pre-collect all possible `doc(cfg)` attributes that will apply to them
when cleaning.
- Add `Item::from_hir_id_and_kind` convenience wrapper
- Make name parameter mandatory
`tcx.opt_item_name` doesn't handle renames, so this is necessary
for any item that could be renamed, which is almost all of them.
- Override visibilities to be `Inherited` for enum variants
`tcx.visibility` returns the effective visibility, not the visibility
that was written in the source code. `pub enum E { A, B }` always has
public variants `A` and `B`, so there's no sense printing `pub` again.
- Don't duplicate handling of `Visibility::Crate`
Instead, represent it as just another `Restricted` path.
- Add `parent_module` to `DocFragment`
- Require the `parent_module` of the item being inlined
- Preserve the hir_id for ExternCrates so rustdoc can find the parent module later
- Take an optional `parent_module` for `build_impl` and `merge_attrs`.
Preserve the difference between parent modules for each doc-comment.
- Support arbitrarily many re-exports in from_ast. In retrospect this is
probably not used and could be simplified to a single
`Option<(Attrs, DefId)>`.
- Don't require the parent_module for all `impl`s, just inlined items
In particular, this will be `None` whenever the attribute is not on a
re-export.
- Only store the parent_module, not the HirId
When re-exporting a re-export, the HirId is not available. Fortunately,
`collect_intra_doc_links` doesn't actually need all the info from a
HirId, just the parent module.
#58972 ignored extern_traits because before #65983 was fixed, they
would always fail to resolve, giving spurious warnings.
This undoes that change, so extern traits are now seen by the
`collect_intra_doc_links` pass. There are also some minor changes in
librustdoc/fold.rs to avoid borrowing the extern_traits RefCell more
than once at a time.
Currently dependency crates of the standard library can sometimes leak
into error messages such as when traits to import are suggested.
Additionally they can leak into documentation such as in the list of
"all traits implemented by `u32`". The dependencies of the standard
library, however, are intended to be private.
The dependencies of the standard library can't actually be stabl-y
imported nor is the documentation that relevant since you can't import
them on stable either. This commit updates both the compiler and rustdoc
to ignore unstable traits in these two scenarios.
Specifically the suggestion for traits to import ignore unstable traits,
and similarly the list of traits implemented by a type excludes unstable
traits.
This commit is extracted from #73441 where the addition of some new
dependencies to the standard library was showed to leak into various
error messages and documentation. The intention here is to go ahead and
land these changes ahead of that since it will likely take some time to
land.
Remove spotlight
I had a few comments saying that this feature was at best misunderstood or not even used so I decided to organize a poll about on [twitter](https://twitter.com/imperioworld_/status/1232769353503956994). After 87 votes, the result is very clear: it's not useful. Considering the amount of code we have just to run it, I think it's definitely worth it to remove it.
r? @kinnison
cc @ollie27
