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>
Make TAIT behave exactly like RPIT
fixes https://github.com/rust-lang/rust/issues/96552
This makes type-alias-impl-trait behave like return-position-impl-trait. Unfortunately it also causes some cases to stop compiling due to "needing type annotations" and makes panicking cause fallback for the hidden type to `()`.
All of these are addressable, but we should probably address them for RPIT and TAIT together
r? ``@lcnr``
Avoid some `&str` to `String` conversions with `MultiSpan::push_span_label`
This patch removes some`&str` to `String` conversions with `MultiSpan::push_span_label`.
Clean up arg mismatch diagnostic, generalize tuple wrap suggestion
This is based on top of #97542, so just look at the last commit which contains the relevant changes.
1. Remove `final_arg_types` which was one of the last places we were using raw (`usize`) indices instead of typed indices in the arg mismatch suggestion code.
2. Improve the tuple wrap suggestion, now we suggest things like `call(a, b, c, d)` -> `call(a, (b, c), d)` 😺
3. Folded in fix#98645
Use typed indices in argument mismatch algorithm
I kinda went overboard with the renames, but in general, "arg" is renamed to "expected", and "input" is renamed to "provided", and we use new typed indices to make sure we're indexing into the right sized array.
Other drive-by changes:
1. Factor this logic into a new function, so we don't need to `break 'label` to escape it.
1. Factored out dependence on `final_arg_types`, which is never populated for arguments greater than the number of expected args. Instead, we just grab the final coerced expression type from `in_progress_typeck_results`.
1. Adjust the criteria we use to print (provided) type names, before we didn't suggest anything that had infer vars, but now we suggest thing that have infer vars but aren't `_`.
~Also, sorry in advance, I kinda want to backport this but I know I have folded in a lot of unnecessary drive-by changes that might discourage that. I would be open to brainstorming how to get some of these changes on beta at least.~ edit: Minimized the ICE-fixing changes to #97557
cc `@jackh726` as author of #92364, and `@estebank` as reviewer of the PR.
fixes#97484
Only keep a single query for well-formed checking
There are currently 3 queries to perform wf checks on different item-likes. This complexity is not required.
This PR replaces the query by:
- one query per item;
- one query to invoke it for a whole module.
This allows to remove HIR `ParItemLikeVisitor`.
Check ADT field is well-formed before checking it is sized
Fixes#96810.
There is one diagnostics regression, in [`src/test/ui/generic-associated-types/bugs/issue-80626.stderr`](https://github.com/rust-lang/rust/pull/97780/files#diff-53795946378e78a0af23a10277c628ff79091c18090fdc385801ee70c1ba6963). I am not super concerned about it, since it's GAT related.
We _could_ fix it, possibly by using the `FieldSized` obligation cause code instead of `BuiltinDerivedObligation`. But that would require changing `Sized` trait confirmation and the `adt_sized_constraint` query.
