diff options
| author | Esteban Küber <esteban@kuber.com.ar> | 2024-02-22 06:15:55 +0000 |
|---|---|---|
| committer | Esteban Küber <esteban@kuber.com.ar> | 2024-02-22 18:56:07 +0000 |
| commit | 5e6da720f621308a0f44e7c6bbd13a9fad68b240 (patch) | |
| tree | f5022996203d2cdd2a051cc91488523a9abd37f0 | |
| parent | 933a05bd0ba91caf219222e5f61d1c92d141ff61 (diff) | |
| download | rust-5e6da720f621308a0f44e7c6bbd13a9fad68b240.tar.gz rust-5e6da720f621308a0f44e7c6bbd13a9fad68b240.zip | |
Account for RPITIT in E0310 explicit lifetime constraint suggestion
When given
```rust
trait Original {
fn f() -> impl Fn();
}
trait Erased {
fn f(&self) -> Box<dyn Fn()>;
}
impl<T: Original> Erased for T {
fn f(&self) -> Box<dyn Fn()> {
Box::new(<T as Original>::f())
}
}
```
avoid suggestion to restrict the `Trait::{opaque}` type in a `where` clause:
```
error[E0310]: the associated type `<T as Original>::{opaque#0}` may not live long enough
--> $DIR/missing-static-bound-from-impl.rs:11:9
|
LL | Box::new(<T as Original>::f())
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| |
| the associated type `<T as Original>::{opaque#0}` must be valid for the static lifetime...
| ...so that the type `impl Fn()` will meet its required lifetime bounds
```
CC #119773.
4 files changed, 36 insertions, 2 deletions
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs index 505d56cf491..470b97b7778 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs @@ -2434,6 +2434,14 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { let suggestion = if has_lifetimes { format!(" + {lt_name}") } else { format!(": {lt_name}") }; suggs.push((sp, suggestion)) + } else if let GenericKind::Alias(ref p) = bound_kind + && let ty::Projection = p.kind(self.tcx) + && let DefKind::AssocTy = self.tcx.def_kind(p.def_id) + && let Some(ty::ImplTraitInTraitData::Trait { .. }) = + self.tcx.opt_rpitit_info(p.def_id) + { + // The lifetime found in the `impl` is longer than the one on the RPITIT. + // Do not suggest `<Type as Trait>::{opaque}: 'static`. } else if let Some(generics) = self.tcx.hir().get_generics(suggestion_scope) { let pred = format!("{bound_kind}: {lt_name}"); let suggestion = format!("{} {}", generics.add_where_or_trailing_comma(), pred); diff --git a/tests/ui/impl-trait/in-trait/async-and-ret-ref.stderr b/tests/ui/impl-trait/in-trait/async-and-ret-ref.stderr index 79a86b0a3ae..15aa3cf54bb 100644 --- a/tests/ui/impl-trait/in-trait/async-and-ret-ref.stderr +++ b/tests/ui/impl-trait/in-trait/async-and-ret-ref.stderr @@ -6,8 +6,6 @@ LL | async fn foo() -> &'static impl T; | | | the associated type `<Self as MyTrait>::{opaque#0}` must be valid for the static lifetime... | ...so that the reference type `&'static impl T` does not outlive the data it points at - | - = help: consider adding an explicit lifetime bound `<Self as MyTrait>::{opaque#0}: 'static`... error: aborting due to 1 previous error diff --git a/tests/ui/impl-trait/in-trait/missing-static-bound-from-impl.rs b/tests/ui/impl-trait/in-trait/missing-static-bound-from-impl.rs new file mode 100644 index 00000000000..a36799c3ebd --- /dev/null +++ b/tests/ui/impl-trait/in-trait/missing-static-bound-from-impl.rs @@ -0,0 +1,16 @@ +trait Original { + fn f() -> impl Fn(); +} + +trait Erased { + fn f(&self) -> Box<dyn Fn()>; +} + +impl<T: Original> Erased for T { + fn f(&self) -> Box<dyn Fn()> { + Box::new(<T as Original>::f()) + //~^ ERROR the associated type `<T as Original>::{opaque#0}` may not live long enough + } +} + +fn main () {} diff --git a/tests/ui/impl-trait/in-trait/missing-static-bound-from-impl.stderr b/tests/ui/impl-trait/in-trait/missing-static-bound-from-impl.stderr new file mode 100644 index 00000000000..5ec0ee38347 --- /dev/null +++ b/tests/ui/impl-trait/in-trait/missing-static-bound-from-impl.stderr @@ -0,0 +1,12 @@ +error[E0310]: the associated type `<T as Original>::{opaque#0}` may not live long enough + --> $DIR/missing-static-bound-from-impl.rs:11:9 + | +LL | Box::new(<T as Original>::f()) + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | | + | the associated type `<T as Original>::{opaque#0}` must be valid for the static lifetime... + | ...so that the type `impl Fn()` will meet its required lifetime bounds + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0310`. |
