diff options
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/object_safety.rs | 28 | ||||
| -rw-r--r-- | src/test/ui/object-safety/issue-102762.rs | 26 | ||||
| -rw-r--r-- | src/test/ui/object-safety/issue-102762.stderr | 20 |
3 files changed, 61 insertions, 13 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs index 8f87a7fdeba..b6f8f51bdf4 100644 --- a/compiler/rustc_trait_selection/src/traits/object_safety.rs +++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs @@ -447,19 +447,6 @@ fn virtual_call_violation_for_method<'tcx>( return Some(MethodViolationCode::Generic); } - if tcx - .predicates_of(method.def_id) - .predicates - .iter() - // A trait object can't claim to live more than the concrete type, - // so outlives predicates will always hold. - .cloned() - .filter(|(p, _)| p.to_opt_type_outlives().is_none()) - .any(|pred| contains_illegal_self_type_reference(tcx, trait_def_id, pred)) - { - return Some(MethodViolationCode::WhereClauseReferencesSelf); - } - let receiver_ty = tcx.liberate_late_bound_regions(method.def_id, sig.input(0)); // Until `unsized_locals` is fully implemented, `self: Self` can't be dispatched on. @@ -538,6 +525,21 @@ fn virtual_call_violation_for_method<'tcx>( } } + // NOTE: This check happens last, because it results in a lint, and not a + // hard error. + if tcx + .predicates_of(method.def_id) + .predicates + .iter() + // A trait object can't claim to live more than the concrete type, + // so outlives predicates will always hold. + .cloned() + .filter(|(p, _)| p.to_opt_type_outlives().is_none()) + .any(|pred| contains_illegal_self_type_reference(tcx, trait_def_id, pred)) + { + return Some(MethodViolationCode::WhereClauseReferencesSelf); + } + None } diff --git a/src/test/ui/object-safety/issue-102762.rs b/src/test/ui/object-safety/issue-102762.rs new file mode 100644 index 00000000000..4f4c3634528 --- /dev/null +++ b/src/test/ui/object-safety/issue-102762.rs @@ -0,0 +1,26 @@ +// compile-flags: --crate-type=lib +// This test checks that the `where_clauses_object_safety` lint does not cause +// other object safety *hard errors* to be suppressed, because we currently +// only emit one object safety error per trait... + +use std::future::Future; +use std::pin::Pin; + +pub trait Fetcher: Send + Sync { + fn get<'a>(self: &'a Box<Self>) -> Pin<Box<dyn Future<Output = Vec<u8>> + 'a>> + where + Self: Sync, + { + todo!() + } +} + +fn fetcher() -> Box<dyn Fetcher> { + //~^ ERROR the trait `Fetcher` cannot be made into an object + todo!() +} + +pub fn foo() { + let fetcher = fetcher(); + let _ = fetcher.get(); +} diff --git a/src/test/ui/object-safety/issue-102762.stderr b/src/test/ui/object-safety/issue-102762.stderr new file mode 100644 index 00000000000..5041ebe7760 --- /dev/null +++ b/src/test/ui/object-safety/issue-102762.stderr @@ -0,0 +1,20 @@ +error[E0038]: the trait `Fetcher` cannot be made into an object + --> $DIR/issue-102762.rs:18:21 + | +LL | fn get<'a>(self: &'a Box<Self>) -> Pin<Box<dyn Future<Output = Vec<u8>> + 'a>> + | ------------- help: consider changing method `get`'s `self` parameter to be `&self`: `&Self` +... +LL | fn fetcher() -> Box<dyn Fetcher> { + | ^^^^^^^^^^^ `Fetcher` cannot be made into an object + | +note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety> + --> $DIR/issue-102762.rs:10:22 + | +LL | pub trait Fetcher: Send + Sync { + | ------- this trait cannot be made into an object... +LL | fn get<'a>(self: &'a Box<Self>) -> Pin<Box<dyn Future<Output = Vec<u8>> + 'a>> + | ^^^^^^^^^^^^^ ...because method `get`'s `self` parameter cannot be dispatched on + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0038`. |