3982eb35ca
Support forwarding caller location through trait object method call Since PR #69251, the `#[track_caller]` attribute has been supported on traits. However, it only has an effect on direct (monomorphized) method calls. Calling a `#[track_caller]` method on a trait object will *not* propagate caller location information - instead, `Location::caller()` will return the location of the method definition. This PR forwards caller location information when `#[track_caller]` is present on the method definition in the trait. This is possible because `#[track_caller]` in this position is 'inherited' by any impls of that trait, so all implementations will have the same ABI. This PR does *not* change the behavior in the case where `#[track_caller]` is present only on the impl of a trait. While all implementations of the method might have an explicit `#[track_caller]`, we cannot know this at codegen time, since other crates may have impls of the trait. Therefore, we keep the current behavior of not forwarding the caller location, ensuring that all implementations of the trait will have the correct ABI. See the modified test for examples of how this works |
||
|---|---|---|
| .. | ||
| src | ||
| Cargo.toml | ||
| README.md | ||
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.