Felix S. Klock II pointed out that this suggestion (introduced in
pull-request #43178 / eac74104) was being issued for one-field-struct
expected types (in which case it is misleading and outright wrong),
even though it was only intended for one-field enum-variants (most
notably, `Some`). Particularly tender-hearted code-historians may be
inclined to show mercy towards the author of #43178 on the grounds
that it's somewhat confusing that struct field definitions are given
in a type called `ty::VariantDef`.
Add a conditional to adhere to the original intent. (It would be
possible to generalize to structs, but not obviously net desirable.)
This adds a level of indentation, so the diff here is going to be
easier to read in ignore-whitespace mode (`-w`).
Resolves#55250.
[NLL] Use new region infer errors when explaining borrows
Use the new free region infer errors for explaining borrows
This gives at least some explanation for why a borrow is expected to
last for a certain free region. Also:
* Reports E0373: "closure may outlive the current function" with NLL.
* Special cases the case of returning a reference to (or value referencing) a local variable or temporary (E0515).
* Special case assigning a reference to a local variable in a closure to a captured variable. (E0521)
Closes#51026 - `regions-nested-fns-2.rs` isn't changed to that diagnostic, since that would not be the correct error here.
Closes#51169
cc #53882 - The error is (IMO) better now, but it could be better when we trace lifetimes in these error messages.
r? @nikomatsakis cc @pnkfelix
This gives at least some explanation for why a borrow is expected to
last for a certain free region. Also:
* Reports E0373: "closure may outlive the current function" with NLL.
* Special cases the case of returning a reference to (or value
referencing) a local variable or temporary (E0515).
* Special case assigning a reference to a local variable in a closure
to a captured variable.
Fixed: Multiple errors on single typo in match pattern
Here we have fixed the case where we were throwing two diagnostic messages `E0026` and `E0027` for same case.
Example
```
error[E0026]: variant `A::A` does not have a field named `fob`
--> src/test/ui/issue-52717.rs:20:12
|
20 | A::A { fob } => { println!("{}", fob); }
| ^^^ variant `A::A` does not have this field
error[E0027]: pattern does not mention field `foo`
--> src/test/ui/issue-52717.rs:20:5
|
20 | A::A { fob } => { println!("{}", fob); }
| ^^^^^^^^^^^^ missing field `foo`
error: aborting due to 2 previous errors
```
Here above we can see that both `E0026` and `E0027` are depicting
same thing.
So, to fix this issue, we are simply checking if for last element of `inexistent_fields` is there any value lies in `unmentioned_fields` using levenshtein algorithm, if it does then for that case we are simply deleting element from `unmentioned_fields`. More or less, now instead of showing separate message in `E0027` we are giving extra hint on `E0026`
r? @estebank
Allow explicit matches on ! without warning
It's now possible to explicitly match on `!` without an unreachable code warning. This seems desirable as promoting explicitness.
Fixes https://github.com/rust-lang/rust/issues/55116.
handle underscore bounds in unexpected places
Per the discussion on #54902, I made it a hard error to use lifetime bounds in various places where they used to be permitted:
- `where Foo: Bar<'_>` for example
I also moved error reporting to HIR lowering and added `Error` variants to let us suppress downstream errors that result.
I (imo) improved the error message wording to be clearer, as well.
In the process, I fixed the ICE in #52098.
Fixes#54902Fixes#52098
In order to output a path that could actually be imported (valid and
visible), we need to handle re-exports correctly.
For example, take `std::os::unix::process::CommandExt`, this trait is
actually defined at `std::sys::unix::ext::process::CommandExt` (at time
of writing).
`std::os::unix` rexports the contents of `std::sys::unix::ext`.
`std::sys` is private so the "true" path to `CommandExt` isn't accessible.
In this case, the visible parent map will look something like this:
(child) -> (parent)
`std::sys::unix::ext::process::CommandExt` -> `std::sys::unix::ext::process`
`std::sys::unix::ext::process` -> `std::sys::unix::ext`
`std::sys::unix::ext` -> `std::os`
This is correct, as the visible parent of `std::sys::unix::ext` is in fact
`std::os`.
When printing the path to `CommandExt` and looking at the current
segment that corresponds to `std::sys::unix::ext`, we would normally
print `ext` and then go to the parent - resulting in a mangled path like
`std::os::ext::process::CommandExt`.
Instead, we must detect that there was a re-export and instead print `unix`
(which is the name `std::sys::unix::ext` was re-exported as in `std::os`).
Also, avoid shadowing of the `ty` variable by giving the `cast_ty` and
`var_ty` variables different names. We want to get the user-provided
type from `cast_ty.hir_id`.
Here we have fixed the case where we were throwing two diagnostic
messages `E0026` and `E0027` for same case like this
Example
error[E0026]: variant `A::A` does not have a field named `fob`
--> src/test/ui/issue-52717.rs:20:12
|
20 | A::A { fob } => { println!("{}", fob); }
| ^^^ variant `A::A` does not have this field
error[E0027]: pattern does not mention field `foo`
--> src/test/ui/issue-52717.rs:20:5
|
20 | A::A { fob } => { println!("{}", fob); }
| ^^^^^^^^^^^^ missing field `foo`
error: aborting due to 2 previous errors
Here above we can see that both `E0026` and `E0027` are depicting
same thing.
So, to fix this issue, we are simply checking element of
`inexistent_fields` is there any value lies in
`unmentioned_fields` using Levenshtein algorithm, if does
then for that case we are simply deleting element from
`unmentioned_fields`. More or less now instead of showing
separate message in `E0027` we are giving extra hint on `E0026`
Address: #52717
