mirror of
https://github.com/rust-lang/rust.git
synced 2025-10-27 19:16:36 +00:00
All hooks receive a `TyCtxtAt` argument. Currently hooks can be called through `TyCtxtAt` or `TyCtxt`. In the latter case, a `TyCtxtAt` is constructed with a dummy span and passed to the hook. However, in practice hooks are never called through `TyCtxtAt`, and always receive a dummy span. (I confirmed this via code inspection, and double-checked it by temporarily making the `TyCtxtAt` code path panic and running all the tests.) This commit removes all the `TyCtxtAt` machinery for hooks. All hooks now receive `TyCtxt` instead of `TyCtxtAt`. There are two existing hooks that use `TyCtxtAt::span`: `const_caller_location_provider` and `try_destructure_mir_constant_for_user_output`. For both hooks the span is always a dummy span, probably unintentionally. This dummy span use is now explicit. If a non-dummy span is needed for these two hooks it would be easy to add it as an extra argument because hooks are less constrained than queries.
For more information about how the query system works, see the rustc dev guide.