fix: Panic while hovering associated function with type annotation on generic param that not inherited from its container type
Fixes#17871
We call `generic_args_sans_defaults` here;
64a140527b/crates/hir-ty/src/display.rs (L1021-L1034)
but the following substitution inside that function panic in #17871;
64a140527b/crates/hir-ty/src/display.rs (L1468)
it's because the `Binders.binder` inside `default_parameters` has a same length with the generics of the function we are hovering on, but the generics of it is split into two, `fn_params` and `parent_params`.
Because of this, it may panic if the function has one or more default parameters and both `fn_params` and `parent_params` are non-empty, like the case in the title of this PR.
So, we must call `generic_args_sans_default` first and then split it into `fn_params` and `parent_params`
fix: Panic while canonicalizing erroneous projection type
Fixes#17866
The root cause of #17866 is quite horrifyng 😨
```rust
trait T {
type A;
}
type Foo = <S as T>::A; // note that S isn't defined
fn main() {
Foo {}
}
```
While inferencing alias type `Foo = <S as T>::A`;
78c2bdce86/crates/hir-ty/src/infer.rs (L1388-L1398)
the error type `S` in it is substituted by inference var in L1396 above as below;
78c2bdce86/crates/hir-ty/src/infer/unify.rs (L866-L869)
This new inference var's index is `1`, as the type inferecing procedure here previously inserted another inference var into same `InferenceTable`.
But after that, the projection type made from the above then passed to the following function;
78c2bdce86/crates/hir-ty/src/traits.rs (L88-L96)
here, a whole new `InferenceTable` is made, without any inference var and in the L94, this table calls;
78c2bdce86/crates/hir-ty/src/infer/unify.rs (L364-L370)
And while registering `AliasEq` `obligation`, this obligation contains inference var `?1` made from the previous table, but this table has only one inference var `?0` made at L365.
So, the chalk panics when we try to canonicalize that obligation to register it, because the obligation contains an inference var `?1` that the canonicalizing table doesn't have.
Currently, we are calling `InferenceTable::new()` to do some normalizing, unifying or coercing things to some targets that might contain inference var that the new table doesn't have.
I think that this is quite dangerous footgun because the inference var is just an index that does not contain the information which table does it made from, so sometimes this "foreign" index might cause panic like this case, or point at the wrong variable.
This PR mitigates such behaviour simply by inserting sufficient number of inference vars to new table to avoid such problem.
This strategy doesn't harm current r-a's intention because the inference vars that passed into new tables are just "unresolved" variables in current r-a, so this is just making sure that such "unresolved" variables exist in the new table
internal: Be more resilient to bad language item definitions in binop inference
Fixes#16287Fixes#16286
There's one more in `write_fn_trait_method_resolution`, but I'm not sure if it won't cause further problems in `infer_closures`.
fix: Resolve included files to their calling modules in IDE layer
Fixes https://github.com/rust-lang/rust-analyzer/issues/17390 at the expense of reporting duplicate diagnostics for modules that have includes in them when both the calling and called file are included.
internal: Reply to requests with defaults when vfs is still loading
There is no reason for us to hit the database with queries when we certainly haven't reached a stable state yet. Instead we just reply with default request results until we are in a state where we can do meaningful work. This should save us from wasting resources while starting up at worst, and at best save us from creating query and interning entries that are non-meaningful which ultimately just end up wasting memory.
internal: Optimize the usage of channel senders
Used `Sender` directly instead of a boxed closure. There is no need to use the boxed closure. This also allows the caller to decide to do something other than `unwrap` (not a fan of it BTW).
Reuse recursion limit as expansion limit
A configurable recursion limit was introduced by looking at the recursion_limit crate attribute. Instead of relying on a global constant we will reuse this value for expansion limit as well.
Addresses: https://github.com/rust-lang/rust-analyzer/issues/8640#issuecomment-2271740272
feat: Implement TAIT and fix ATPIT a bit
Closes#16296 (Commented on the issue)
In #16852, I implemented ATPIT, but as I didn't discern ATPIT and other non-assoc TAIT, I guess that it has been working for some TAITs.
As the definining usage of TAIT requires it should be appear in the Def body's type(const blocks' type annotations or functions' signatures), this can be done in simlilar way with ATPIT
And this PR also corrects some defining-usage resolution for ATPIT
