It sees them as regular impls; the details are abstracted. It's beautiful for the IDE layer, and less beautiful for `hir`, so this is a big change.
Some small differences still exist:
- We show builtin derives impl (to the IDE layer) as if they have had no generic parameters. It is possible to show the parameters, but that means also having to handle fake impls in `TypeParam` etc., and the benefit is questionable.
- Getting the fn *def* type of a method of a builtin derive impl is not supported, as there is no real `FunctionId`, therefore no `CallableDefId`. The trait method is returned instead. Note: getting the fn *ptr* type of the method is supported well.
- Builtin derive impls and their methods do not fully support `HasSource`, because, well, they have no source (at least, not in the form of `ast::Impl` and `ast::Fn`). To support them, we use the derive's `TextRange` where possible, and the trait method's source when not.
It's important to note that the def map still records the `MacroCallId`. I have doubts over this, as this means it's very easy to create the queries we don't want to create, but it does make things more convenient. In particular, a nicety of this setup is that even "Expand macro recursively" works (it creates the macro input/output query, but given that they will only be created when the user invokes the command, that does not seem to be a problem).
Changes:
- `const_of_item()` was added to `Interner`, analogous to `type_of()`. No strongly-typed ID (yet).
- New solver trait lang item: `TrivialClone`.
- `TypeRelation` changed a bit, the code was copied from rustc.
So that we'll correctly treat it as an attribute.
I don't like that we have to register every builtin macro even if we don't need it, but that's what we got.
It cannot be exactly the same, because we have needs rustc doesn't have (namely, accurate enumeration of all methods, not just with a specific name, for completions etc., while rustc also needs a best-effort implementation for diagnostics) but it is closer than the previous impl.
In addition we rewrite the closely related handling of operator inference and impl collection.
This in turn necessitate changing some other parts of inference in order to retain behavior. As a result, the behavior more closely matches rustc and is also more correct.
This fixes 2 type mismatches on self (1 remains) and 4 diagnostics (1 remains), plus some unknown types.
`concat_idents!` was deprecated in [1] and will be removed in the near
future. rust-analyzer's support is independent of rustc's, so drop RA
support now to make syncing easier.
[1]: https://github.com/rust-lang/rust/pull/137653
Use `std::mem::{size_of, size_of_val, align_of, align_of_val}` from the
prelude instead of importing or qualifying them.
These functions were added to all preludes in Rust 1.80.
And add a new diagnostic for non-`Fn` parenthesized generic args.
Path lowering started to look like a mess, with each function carrying additional parameters for the diagnostic callback (since paths can occur both in type and in expression/pattern position, and their diagnostic handling is different) and the segment index, for the diagnostics report. So I refactored it from stateless functions on `TyLoweringContext` into stateful struct, `PathLoweringContext`, that tracks the process of lowering a path from resolution til assoc types selection.
Similar to how the alignment is already checked, this adds a check
for null pointer dereferences in debug mode. It is implemented similarly
to the alignment check as a MirPass.
This is related to a 2025H1 project goal for better UB checks in debug
mode: https://github.com/rust-lang/rust-project-goals/pull/177.
