5971: Implement async blocks r=flodiebold a=oxalica
Fix#4018
@flodiebold already gave a generic guide in the issue. Here's some concern about implementation detail:
- Chalk doesn't support generator type yet.
- Adding generator type as a brand new type (ctor) can be complex and need to *re-introduced* builtin impls. (Like how we implement closures before native closure support of chalk, which is already removed in #5401 )
- The output type of async block should be known after type inference of the whole body.
- We cannot directly get the type from source like return-positon-impl-trait. But we still need to provide trait bounds when chalk asking for `opaque_ty_data`.
- During the inference, the output type of async block can be temporary unknown and participate the later inference.
`let a = async { None }; let _: i32 = a.await.unwrap();`
So in this PR, the type of async blocks is inferred as an opaque type parameterized by the `Future::Output` type it should be, like what we do with closure type.
And it really works now.
Well, I still have some questions:
- The bounds `AsyncBlockImplType<T>: Future<Output = T>` is currently generated in `opaque_ty_data`. I'm not sure if we should put this code here.
- Type of async block is now rendered as `impl Future<Output = OutputType>`. Do we need to special display to hint that it's a async block? Note that closure type has its special format, instead of `impl Fn(..) -> ..` or function type.
Co-authored-by: oxalica <oxalicc@pm.me>
5682: Add an option to disable diagnostics r=matklad a=popzxc
As far as I know, currently it's not possible to disable a selected type of diagnostics provided by `rust-analyzer`.
This causes an inconvenient situation with a false-positive warnings: you either have to disable all the diagnostics, or you have to ignore these warnings.
There are some open issues related to this problem, e.g.: https://github.com/rust-analyzer/rust-analyzer/issues/5412, https://github.com/rust-analyzer/rust-analyzer/issues/5502
This PR attempts to make it possible to selectively disable some diagnostics on per-project basis.
Co-authored-by: Igor Aleksanov <popzxc@yandex.ru>
