Do not error during method probe on `Sized` predicates for types that aren't the method receiver
Fixes#61525
This is safe even though we're skipping an error because we end up confirming the method, which means we're still checking the `Sized` predicate in the end. It just means that we don't emit an erroneous message as below:
```
error: the `query` method cannot be invoked on a trait object
--> src/lib.rs:14:11
|
14 | 1.query::<dyn ToString>("")
| ^^^^^
|
= note: another candidate was found in the following trait, perhaps add a `use` for it:
`use crate::Example;`
```
Also fixes erroneously suggesting the same trait over again, as seen in the `issue-35976.rs` UI test.
Mention similarly named associated type even if it's not clearly in supertrait
Due to query cycle avoidance, we sometimes restrict the candidates in `complain_about_assoc_type_not_found` too much so that we can't detect typo replacements from just supertraits.
This creates a more general note of the existence of a similarly named associated type from _all_ visible traits when possible.
Fixes#55673
Implement `SourceMap::is_span_accessible`
This patch adds `SourceMap::is_span_accessible` and replaces `span_to_snippet(span).is_ok()` and `span_to_snippet(span).is_err()` with it. This removes a `&str` to `String` conversion.
Track implicit `Sized` obligations in type params
When we evaluate `ty::GenericPredicates` we introduce the implicit
`Sized` predicate of type params, but we do so with only the `Predicate`
its `Span` as context, we don't have an `Obligation` or
`ObligationCauseCode` we could influence. To try and carry this
information through, we add a new field to `ty::GenericPredicates` that
tracks both which predicates come from a type param and whether that
param has any bounds already (to use in suggestions).
We also suggest adding a `?Sized` bound if appropriate on E0599.
Address part of #98539.
Add a `-Zdump-drop-tracking-cfg` debugging flag
This is useful for debugging drop-tracking; previously, you had to recompile
rustc from source and manually add a call to `write_graph_to_file`. This
makes the option more discoverable and configurable at runtime.
I also took the liberty of making the labels for the CFG nodes much easier to read:
previously, they looked like `id(2), local_id: 48`, now they look like
```
expr from_config (hir_id=HirId { owner: DefId(0:10 ~ default_struct_update[79f9]::foo), local_id: 2})
```
r? ``@eholk``
Do not fetch HIR to compute variances.
Everything can be done using higher-level queries. This simplifies the code, and should allow better incremental caching.
more `need_type_info` improvements
this now deals with macros in suggestions and the source cost computation does what I want for `channel` 🎉
r? ``@estebank``
Improve some inference diagnostics
- Properly point out point location where "type must be known at this point", or else omit the note if it's not associated with a useful span.
- Fix up some type ambiguity diagnostics, errors shouldn't say "cannot infer type for reference `&'a ()`" when the given type has no inference variables.
Suggest blanket impl to the local traits
This PR will add additional suggestion regarding the blanket implementation when it is possible, by generation a new help message + suggestion.
Closes https://github.com/rust-lang/rust/issues/96076
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
