fix: sort and deduplicate auto traits in trait object types
Fixes#12739
Chalk solver doesn't sort and deduplicate auto traits in trait object types, so we need to handle them ourselves in the lowering phase, just like [`rustc`](880416180b/compiler/rustc_typeck/src/astconv/mod.rs (L1487-L1488)) and [`chalk-integration`](https://github.com/rust-lang/chalk/blob/master/chalk-integration/src/lowering.rs#L575) do.
Quoting from [the Chalk book](https://rust-lang.github.io/chalk/book/types/rust_types.html#dyn-types):
> Note that -- for this purpose -- ordering of bounds is significant. That means that if you create a `dyn Foo + Send` and a `dyn Send + Foo`, chalk would consider them distinct types. The assumption is that bounds are ordered in some canonical fashion somewhere else.
Also, trait object types with more than one non-auto traits were previously allowed, but are now disallowed with this patch.
fix: Fix panics on GATs involving const generics
This workaround avoids constant crashing of rust analyzer when using GATs with const generics,
even when the const generics are only on the `impl` block.
The workaround treats GATs as non-existing if either itself or the parent has const generics and
removes relevant panicking code-paths.
Fixes#11989, fixes#12193
This workaround avoids constant crashing of rust analyzer when using GATs with const generics,
even when the const generics are only on the `impl` block.
The workaround treats GATs as non-existing if either itself or the parent has const generics and
removes relevant panicking code-paths.
feat: Show witnesses of non-exhaustiveness in `missing-match-arm` diagnostic
Shamelessly copied from rustc. Thus reporting format is same.
This extends public api `hir::diagnostics::MissingMatchArms` with `uncovered_patterns: String` field. It does not expose data for implementing a quick fix yet.
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Worth to note: current implementation does not give a comprehensive list of missing patterns. Also mentioned in [paper](http://moscova.inria.fr/~maranget/papers/warn/warn.pdf):
> One may think that algorithm I should make an additional effort to provide more
> non-matching values, by systematically computing recursive calls on specialized
> matrices when possible, and by returning a list of all pattern vectors returned by
> recursive calls. We can first observe that it is not possible in general to supply the
> users with all non-matching values, since the signature of integers is (potentially)
> infinite.
