Move top part of print_item to Tera templates
Part of #84419.
This moves the first line of each item page (E.g. `Struct foo::Bar .... 1.0.0 [-][src]` into a Tera template.
I also moved template initialization into its own module and added a small macro to reduce duplication and opportunity for errors.
Fix invalid HTML generation for higher bounds
Considering this is a bug, I cherry-picked the commit from #89676 so it's merged more quickly.
r? ``@notriddle``
Make cfg imply doc(cfg)
This is a reopening of #79341, rebased and modified a bit (we made a lot of refactoring in rustdoc's types so they needed to be reflected in this PR as well):
* `hidden_cfg` is now in the `Cache` instead of `DocContext` because `cfg` information isn't stored anymore on `clean::Attributes` type but instead computed on-demand, so we need this information in later parts of rustdoc.
* I removed the `bool_to_options` feature (which makes the code a bit simpler to read for `SingleExt` trait implementation.
* I updated the version for the feature.
There is only one thing I couldn't figure out: [this comment](https://github.com/rust-lang/rust/pull/79341#discussion_r561855624)
> I think I'll likely scrap the whole `SingleExt` extension trait as the diagnostics for 0 and >1 items should be different.
How/why should they differ?
EDIT: this part has been solved, the current code was fine, just needed a little simplification.
cc `@Nemo157`
r? `@jyn514`
Original PR description:
This is only active when the `doc_cfg` feature is active.
The implicit cfg can be overridden via `#[doc(cfg(...))]`, so e.g. to hide a `#[cfg]` you can use something like:
```rust
#[cfg(unix)]
#[doc(cfg(all()))]
pub struct Unix;
```
By adding `#![doc(cfg_hide(foobar))]` to the crate attributes the cfg `#[cfg(foobar)]` (and _only_ that _exact_ cfg) will not be implicitly treated as a `doc(cfg)` to render a message in the documentation.
librustdoc: Use correct heading levels.
Closes#89309
This fixes the `<h#>` header tags throughout the docs to reflect a semantic hierarchy.
- I ran a script to manually check that we don't have any files with multiple `<h1>` tags.
- Also checked that we never incorrectly nest e.g. a `<h2>` under an `<h3>`.
- I also spot-checked a bunch of pages (`trait.Read`, `enum.Ordering`, `primitive.isize`, `trait.Iterator`).
By adding #![doc(cfg_hide(foobar))] to the crate attributes the cfg
#[cfg(foobar)] (and _only_ that _exact_ cfg) will not be implicitly
treated as a doc(cfg) to render a message in the documentation.
This is only active when the `doc_cfg` feature is active.
The implicit cfg can be overridden via #[doc(cfg(...))], so e.g. to
hide a #[cfg] you can use something like:
```rust
#[cfg(unix)]
#[doc(cfg(all()))]
pub struct Unix;
```
(since `all()` is always true, it is never shown in the docs)
The change to `impl Clean<Path> for hir::TraitRef<'_>` was necessary to
fix a test failure for `src/test/rustdoc/trait-alias-mention.rs`.
Here's why:
The old code path was through `impl Clean<Type> for hir::TraitRef<'_>`,
which called `resolve_type`, which in turn called `register_res`. Now,
because `PolyTrait` uses a `Path` instead of a `Type`, the impl of
`Clean<Path>` was being run, which did not call `register_res`, causing
the trait alias to not be recorded in the `external_paths` cache.
It should only ever be a `ResolvedPath`, so this (a) enforces that, and
(b) reduces the size of `Impl`.
I had to update a test because the order of the rendered auto trait impl
bounds changed. I think the order changed because rustdoc sorts auto
trait bounds using their `Debug` output.
Fix union keyword highlighting in rustdoc HTML sources
I followed this logic: if I find an ident "union", I check if it followed by another ident or not. If it's the case, then I consider this is a keyword because it's declaring a union type.
To do so I created a new Iterator which allows to peek the next items without moving the current iterator position.
This is part of https://github.com/rust-lang/rust/issues/85016. If the fix makes sense, I'll extend it to other weak keywords (the issue only mentions they exist but https://doc.rust-lang.org/nightly/reference/keywords.html#weak-keywords only talks about `dyn` and `'static` so not sure if there is anything else to be done?).
cc `@notriddle` (you're one of the last ones who worked on this part of rustdoc so here you go 😉 )
r? `@jyn514`
Use the correct edition for syntax highlighting doctests
Previously it would unconditionally use edition 2015, which was incorrect.
Helps with https://github.com/rust-lang/rust/issues/89135 in that you can now override the doctest to be 2018 edition instead of being forced to fix the error. This doesn't resolve any of the deeper problems that rustdoc disagrees with most rust users on what a code block is.
cc `@Mark-Simulacrum`
rustdoc: Cleanup `clean` part 2
Split out from #88379. This contains the following commits from that PR:
- Remove `Type::ResolvedPath.is_generic`
- Rename `is_generic()` to `is_assoc_ty()`
r? `@jyn514`
