feat: make `let_binding_suggestion` more reasonable
This is my first PR for rustc, which trying to fix https://github.com/rust-lang/rust/issues/117894, I am not familiar with some internal api so maybe some modification here isn't the way to go, appreciated for any review suggestion.
Suggest field typo through derefs
Take into account implicit dereferences when suggesting fields.
```
error[E0609]: no field `longname` on type `Arc<S>`
--> $DIR/suggest-field-through-deref.rs:10:15
|
LL | let _ = x.longname;
| ^^^^^^^^ help: a field with a similar name exists: `long_name`
```
CC https://github.com/rust-lang/rust/issues/78374#issuecomment-719564114
Take into account implicit dereferences when suggesting fields.
```
error[E0609]: no field `longname` on type `Arc<S>`
--> $DIR/suggest-field-through-deref.rs:10:15
|
LL | let _ = x.longname;
| ^^^^^^^^ help: a field with a similar name exists: `long_name`
```
CC https://github.com/rust-lang/rust/issues/78374#issuecomment-719564114
Always point at index span on index obligation failure
Use more targetted span for index obligation failures by rewriting the obligation cause span.
CC #66023
Add `std:#️⃣:{DefaultHasher, RandomState}` exports (needs FCP)
This implements rust-lang/libs-team#267 to move the libstd hasher types to `std::hash` where they belong, instead of `std::collections::hash_map`.
<details><summary>The below no longer applies, but is kept for clarity.</summary>
This is a small refactor for #27242, which moves the definitions of `RandomState` and `DefaultHasher` into `std::hash`, but in a way that won't be noticed in the public API.
I've opened rust-lang/libs-team#267 as a formal ACP to move these directly into the root of `std::hash`, but for now, they're at least separated out from the collections code in a way that will make moving that around easier.
I decided to simply copy the rustdoc for `std::hash` from `core::hash` since I think it would be ideal for the two to diverge longer-term, especially if the ACP is accepted. However, I would be willing to factor them out into a common markdown document if that's preferred.
</details>
When we have a resolution error when looking at a fully qualified path
on a type, look for all associated functions on inherent impls that
return `Self` and mention them to the user.
Fix#69512.
When an associated type with GATs isn't specified in a `dyn Trait`, emit
an object safety error instead of only complaining about the missing
associated type, as it will lead the user down a path of three different
errors before letting them know that what they were trying to do is
impossible to begin with.
Fix#103155.
notes
This commit extends the `#[diagnostic::on_unimplemented]` (and
`#[rustc_on_unimplemented]`) attributes to allow multiple `note`
options. This enables emitting multiple notes for custom error messages.
For now I've opted to not change any of the existing usages of
`#[rustc_on_unimplemented]` and just updated the relevant compile tests.
Separate move path tracking between borrowck and drop elaboration.
The primary goal of this PR is to skip creating a `MovePathIndex` for path that do not need dropping in drop elaboration.
The 2 first commits are cleanups.
The next 2 commits displace `move` errors from move-path builder to borrowck. Move-path builder keeps the same logic, but does not carry error information any more.
The remaining commits allow to filter `MovePathIndex` creation according to types. This is used in drop elaboration, to avoid computing dataflow for paths that do not need dropping.
Typo suggestion to change bindings with leading underscore
When encountering a binding that isn't found but has a typo suggestion for a binding with a leading underscore, suggest changing the binding definition instead of the use place.
Fix#60164.
When encountering a binding that isn't found but has a typo suggestion
for a binding with a leading underscore, suggest changing the binding
definition instead of the use place.
Fix#60164.
When encountering a for loop that is rejected by the borrow checker
because it is being advanced within its body, provide a structured
suggestion for `while let Some(pat) = iter.next()`.
Show more information when multiple `impl`s apply
- When there are `impl`s without type params, show only those (to avoid showing overly generic `impl`s).
```
error[E0283]: type annotations needed
--> $DIR/multiple-impl-apply.rs:34:9
|
LL | let y = x.into();
| ^ ---- type must be known at this point
|
note: multiple `impl`s satisfying `_: From<Baz>` found
--> $DIR/multiple-impl-apply.rs:14:1
|
LL | impl From<Baz> for Bar {
| ^^^^^^^^^^^^^^^^^^^^^^
...
LL | impl From<Baz> for Foo {
| ^^^^^^^^^^^^^^^^^^^^^^
= note: required for `Baz` to implement `Into<_>`
help: consider giving `y` an explicit type
|
LL | let y: /* Type */ = x.into();
| ++++++++++++
```
- Lower the importance of `T: Sized`, `T: WellFormed` and coercion errors, to prioritize more relevant errors. The pre-existing deduplication logic deals with hiding redundant errors better that way, and we show errors with more metadata that is useful to the user.
- Show `<SelfTy as Trait>::assoc_fn` suggestion in more cases.
```
error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type
--> $DIR/cross-return-site-inference.rs:38:16
|
LL | return Err(From::from("foo"));
| ^^^^^^^^^^ cannot call associated function of trait
|
help: use a fully-qualified path to a specific available implementation
|
LL | return Err(</* self type */ as From>::from("foo"));
| +++++++++++++++++++ +
```
Fix#88284.
Add a note to duplicate diagnostics
Helps explain why there may be a difference between manual testing and the test suite output and highlights them as something to potentially look into
For existing duplicate diagnostics I just blessed them other than a few files that had other `NOTE` annotations in
In `report_fullfillment_errors` push back `T: Sized`, `T: WellFormed`
and coercion errors to the end of the list. The pre-existing
deduplication logic eliminates redundant errors better that way, keeping
the resulting output with fewer errors than before, while also having
more detail.
More accurate suggestion for `self.` and `Self::`
Detect that we can't suggest `self.` in an associated function without `&self` receiver.
Partially address #115992.
r? ``@compiler-errors``
