4497: Create LowerCtx on the fly r=matklad a=edwin0cheng
Previously we create `LowerCtx` at the beginning of lowering, however, the hygiene content is in fact changing between macro expression expanding.
This PR change it to create the `LowerCtx` on the fly to fix above bug.
However, #4465 is not fixed by this PR, the goto-def is still not work yet. It only fixed the infer part.
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
This fixes an issue where the following code sample would fail to infer
the type contained in the option:
```rust
fn main() {
let mut end = None; // TODO: Fix inference for this in RA
loop {
end = Some(true);
}
}
```
4175: Introduce HirDisplay method for rendering source code & use it in add_function assist r=flodiebold a=TimoFreiberg
Next feature for #3639.
So far the only change in the new `HirDisplay` method is that paths are qualified, but more changes will be necessary (omitting the function name from function types, returning an error instead of printing `"{unknown}"`, probably more).
Is that approach okay?
Co-authored-by: Timo Freiberg <timo.freiberg@gmail.com>
E.g. in
```rust
match x {
1 => function1,
2 => function2,
}
```
we need to try coercing both to pointers. Turns out this is a special case in
rustc as well (see the link in the comment).
Divergence here means that for some reason, the end of a block will not be
reached. We tried to model this just using the never type, but that doesn't work
fully (e.g. in `let x = { loop {}; "foo" };` x should still have type `&str`);
so this introduces a `diverges` flag that the type checker keeps track of, like
rustc does.
4173: Use core instead of std for builtin derive macros r=edwin0cheng a=edwin0cheng
Fixed#4087.
We can't use `$crate` here right now because :
1. We have to able to detect `macro` 2.0 in collecting phase for finding `rustc_builtin_macro` attrs.
2. And we have to make hygiene works for builtin derive macro.
r= @flodiebold
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
So e.g. if we have `fn foo<T: SomeTrait<u32>>() -> T::Item`, we want to lower
that to `<T as SomeTrait<u32>>::Item` and not `<T as SomeTrait<_>>::Item`.
We need to shift in when we're substituting inside a binder.
This should fix#4053 (it doesn't fix the occasional overflow that also occurs
on the Diesel codebase though).
4023: Fix another crash from wrong binders r=matklad a=flodiebold
Basically, if we had something like `dyn Trait<T>` (where `T` is a type parameter) in an impl we lowered that to `dyn Trait<^0.0>`, when it should be `dyn Trait<^1.0>` because the `dyn` introduces a new binder. With one type parameter, that's just wrong, with two, it'll lead to crashes.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
Basically, if we had something like `dyn Trait<T>` (where `T` is a type
parameter) in an impl we lowered that to `dyn Trait<^0.0>`, when it should be
`dyn Trait<^1.0>` because the `dyn` introduces a new binder. With one type
parameter, that's just wrong, with two, it'll lead to crashes.
Fixes a lot of false type mismatches.
(And as always when touching the unification code, I have to say I'm looking
forward to replacing it by Chalk's...)
3966: Add support for bounds on associated types in trait definitions r=matklad a=flodiebold
E.g.
```rust
trait Trait {
type Item: SomeOtherTrait;
}
```
Note that these don't simply desugar to where clauses; as I understand it, where clauses have to be proved by the *user* of the trait, but these bounds are proved by the *implementor*. (Also, where clauses on associated types are unstable.)
(Another one from my recursive solver branch...)
3968: Remove format from syntax_bridge hot path r=matklad a=edwin0cheng
Although only around 1% speed up by running:
```
Measure-Command {start-process .\target\release\rust-analyzer "analysis-stats -q ." -NoNewWindow -wait}
```
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
3964: Nicer Chalk debug logs r=matklad a=flodiebold
I'm looking at a lot of Chalk debug logs at the moment, so here's a few changes to make them slightly nicer...
3965: Implement inline associated type bounds r=matklad a=flodiebold
Like `Iterator<Item: SomeTrait>`.
This is an unstable feature, but it's used in the standard library e.g. in the definition of Flatten, so we can't get away with not implementing it :)
(This is cherry-picked from my recursive solver branch, where it works better, but I did manage to write a test that works with the current Chalk solver as well...)
3967: Handle `Self::Type` in trait definitions when referring to own associated type r=matklad a=flodiebold
It was implemented for other generic parameters for the trait, but not for `Self`.
(Last one off my recursive solver branch 😄 )
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
E.g.
```
trait Trait {
type Item: SomeOtherTrait;
}
```
Note that these don't simply desugar to where clauses; as I understand it, where
clauses have to be proved by the *user* of the trait, but these bounds are proved
by the *implementor*. (Also, where clauses on associated types are unstable.)
Like `Iterator<Item: SomeTrait>`.
This is an unstable feature, but it's used in the standard library e.g. in the
definition of Flatten, so we can't get away with not implementing it :)
We treat macro calls as expressions (there's appropriate Into impl),
which causes problem if there's expresison and non-expression macro in
the same node (like in the match arm).
We fix this problem by nesting macor patterns into another node (the
same way we nest path into PathExpr or PathPat). Ideally, we probably
should add a similar nesting for macro expressions, but that needs
some careful thinking about macros in blocks: `{ am_i_expression!() }`.
