Stop using CRATE_DEF_INDEX outside of metadata encoding.
`CRATE_DEF_ID` and `CrateNum::as_def_id` are almost always what we want. We should not manipulate raw `DefIndex` outside of metadata encoding.
It was previously defined in `render::search_index` but wasn't used at
all there. `clean::types` seems like a better fit since that's where
`ExternalCrate` is defined.
I would like to rename it to `Type::Path`, but then it can't be
re-exported since the name would conflict with the `Path` struct.
Usually enum variants are referred to using their qualified names in
Rust (and parts of rustdoc already do that with `clean::Type`), so this
is also more consistent with the language.
This change has two advantages:
1. It makes the possible states clearer, and it makes it impossible to
construct invalid states, such as a blanket impl that is also an auto
trait impl.
2. It shrinks the size of `Impl` a bit, since now there is only one
field, rather than two.
It should be preferred over `def_id_no_primitives()`, so it should have
a shorter name. I also put it before `def_id_no_primitives()` so that it
shows up first in the docs.
Now that it's only implemented for `Type`, using inherent methods
instead means that imports are no longer necessary. Also, `GetDefId` is
only meant to be used with `Type`, so it shouldn't be a trait.
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.
rustdoc: Cleanup `clean` part 1
Split out from #88379.
These commits are completely independent of each other, and each is a fairly
small change (the last few are new commits; they are not from #88379):
- Remove unnecessary `Cache.*_did` fields
- rustdoc: Get symbol for `TyParam` directly
- Create a valid `Res` in `external_path()`
- Remove unused `hir_id` parameter from `resolve_type`
- Fix redundant arguments in `external_path()`
- Remove unnecessary `is_trait` argument
- rustdoc: Cleanup a pattern match in `external_generic_args()`
r? ``@jyn514``
- Fix broken handling of primitive associated items
- Remove fragment hack
Fixes 83083
- more logging
- Update CrateNum hacks
The CrateNum has no relation to where in the dependency tree the crate
is, only when it's loaded. Explicitly special-case core instead of
assuming it will be the first DefId.
- Update and add tests
- Cache calculation of primitive locations
This could possibly be avoided by passing a Cache into
collect_intra_doc_links; but that's a much larger change, and doesn't
seem valuable other than for this.
## What is an HTML root url?
It tells rustdoc where it should link when documentation for a crate is
not available locally; for example, when a crate is a dependency of a
crate documented with `cargo doc --no-deps`.
## What is the difference between `html_root_url` and `--extern-html-root-url`?
Both of these tell rustdoc what the HTML root should be set to.
`doc(html_root_url)` is set by the crate author, while
`--extern-html-root-url` is set by the person documenting the crate.
These are often different. For example, docs.rs uses
`--extern-html-root-url https://docs.rs/crate-name/version` to ensure
all crates have documentation, even if `html_root_url` is not set.
Conversely, crates such as Rocket set `doc(html_root_url =
"https://api.rocket.rs")`, because they prefer users to view the
documentation on their own site.
Crates also set `html_root_url` to ensure they have
documentation when building locally when offline. This is unfortunate to
require, because it's more work from the library author. It also makes
it impossible to distinguish between crates that want to be viewed on a
different site (e.g. Rocket) and crates that just want documentation to
be visible offline at all (e.g. Tokio). I have authored a separate
change to the API guidelines to no longer recommend doing this:
https://github.com/rust-lang/api-guidelines/pull/230.
## Why change the default?
In the past, docs.rs has been the main user of `--extern-html-root-url`.
However, it's useful for other projects as well. In particular, Cargo
wants to pass it by default when running `--no-deps`
(https://github.com/rust-lang/cargo/issues/8296).
Unfortunately, for these other use cases, the priority order is
inverted. They want to give *precedence* to the URL the crate picks, and
only fall back to the `--extern-html-root` if no `html_root_url` is
present. That allows passing `--extern-html-root` unconditionally,
without having to parse the source code to see what attributes are
present.
For docs.rs, however, we still want to keep the old behavior, so that
all links on docs.rs stay on the site.
