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Rollup merge of #125987 - estebank:issue-122622, r=Nadrieril

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When `derive`ing, account for HRTB on `BareFn` fields

When given

```rust
trait SomeTrait {
    type SomeType<'a>;
}

#[derive(Clone)]
struct Foo<T: SomeTrait> {
    x: for<'a> fn(T::SomeType<'a>)
}
```

expand to

```rust
impl<T: ::core::clone::Clone + SomeTrait> ::core::clone::Clone for Foo<T>
    where for<'a> T::SomeType<'a>: ::core::clone::Clone {
    #[inline]
    fn clone(&self) -> Foo<T> {
        Foo { x: ::core::clone::Clone::clone(&self.x) }
    }
}
```

instead of the previous invalid

```
impl<T: ::core::clone::Clone + SomeTrait> ::core::clone::Clone for Foo<T>
    where T::SomeType<'a>: ::core::clone::Clone {
    #[inline]
    fn clone(&self) -> Foo<T> {
        Foo { x: ::core::clone::Clone::clone(&self.x) }
    }
}
```

Fix #122622.

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This commit is contained in:
Matthias Krüger 2024-06-06 04:17:26 +02:00 • committed by GitHub
commit 55b76f4720
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2 changed files with 24 additions and 1 deletions
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12
compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
View file

@ -412,6 +412,15 @@ fn find_type_parameters(
impl<'a, 'b> visit::Visitor<'a> for Visitor<'a, 'b> {
fn visit_ty(&mut self, ty: &'a ast::Ty) {
let stack_len = self.bound_generic_params_stack.len();
if let ast::TyKind::BareFn(bare_fn) = &ty.kind
&& !bare_fn.generic_params.is_empty()
{
// Given a field `x: for<'a> fn(T::SomeType<'a>)`, we wan't to account for `'a` so
// that we generate `where for<'a> T::SomeType<'a>: ::core::clone::Clone`. #122622
self.bound_generic_params_stack.extend(bare_fn.generic_params.iter().cloned());
}
if let ast::TyKind::Path(_, path) = &ty.kind
&& let Some(segment) = path.segments.first()
&& self.ty_param_names.contains(&segment.ident.name)
@ -422,7 +431,8 @@ fn find_type_parameters(
});
}
visit::walk_ty(self, ty)
visit::walk_ty(self, ty);
self.bound_generic_params_stack.truncate(stack_len);
}
// Place bound generic params on a stack, to extract them when a type is encountered.