The previous error was confusing since it made it sound like you can't
link to items that are defined outside the current module.
Also suggested importing the item.
Previously, these were spread throughout the codebase. This had two
drawbacks:
1. It caused the fast path to be slower: even if a link resolved,
rustdoc would still perform various lookups for the error diagnostic.
2. It was inconsistent and didn't always give all diagnostics (https://github.com/rust-lang/rust/issues/76925)
Now, diagnostics only perform expensive lookups in the error case.
Additionally, the error handling is much more consistent, both in
wording and behavior.
- Remove `CannotHaveAssociatedItems`, `NotInScope`, `NoAssocItem`, and `NotAVariant`
in favor of the more general `NotResolved`
`resolution_failure` will now look up which of the four above
categories is relevant, instead of requiring the rest of the code to
be consistent and accurate in which it picked.
- Remove unnecessary lookups throughout the intra-doc link pass. These
are now done by `resolution_failure`.
+ Remove unnecessary `extra_fragment` argument to `variant_field()`;
it was only used to do lookups on failure.
+ Remove various lookups related to associated items
+ Remove distinction between 'not in scope' and 'no associated item'
- Don't perform unnecessary copies
- Remove unused variables and code
- Update tests
- Note why looking at other namespaces is still necessary
- 'has no inner item' -> 'contains no item'
bless tests
Before:
```
= note: this link partially resolves to the struct `S`
= note: no `fmt` in `S`
```
After:
```
= note: the struct `S` has no field or associated item named `fmt`
```
This commit refactors intra-doc link error reporting to deduplicate code
and decouple error construction from the type of error. This greatly
improves flexibility at each error construction site, while reducing the
complexity of the diagnostic creation.
This commit also rewords the diagnostics for clarity and style:
- Diagnostics should not end in periods.
- It's unnecessary to say "ignoring it". Since this is a warning by
default, it's already clear that the link is ignored.
This commit improves the calculation of code spans for intra-doc
resolution failures. All sugared doc comments should now have the
correct spans, including those where the comment is longer than the
docs.
It also fixes an issue where the spans were calculated incorrectly for
certain unsugared doc comments. The diagnostic will now always use the
span of the attributes, as originally intended.
Fixes#55964.
