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fix: handle trait methods as inherent methods for placeholders
| -rw-r--r-- | crates/hir-ty/src/method_resolution.rs | 87 | ||||
| -rw-r--r-- | crates/hir-ty/src/tests/method_resolution.rs | 17 |
2 files changed, 77 insertions, 27 deletions
diff --git a/crates/hir-ty/src/method_resolution.rs b/crates/hir-ty/src/method_resolution.rs index c0ef4b2a9d..dbf2750032 100644 --- a/crates/hir-ty/src/method_resolution.rs +++ b/crates/hir-ty/src/method_resolution.rs @@ -914,19 +914,10 @@ fn iterate_trait_method_candidates( let db = table.db; let env = table.trait_env.clone(); let self_is_array = matches!(self_ty.kind(Interner), chalk_ir::TyKind::Array(..)); - let env_traits = matches!(self_ty.kind(Interner), TyKind::Placeholder(_)) - // if we have `T: Trait` in the param env, the trait doesn't need to be in scope - .then(|| { - env.traits_in_scope_from_clauses(self_ty.clone()) - .flat_map(|t| all_super_traits(db.upcast(), t)) - }) - .into_iter() - .flatten(); - let traits = env_traits.chain(traits_in_scope.iter().copied()); let canonical_self_ty = table.canonicalize(self_ty.clone()).value; - 'traits: for t in traits { + 'traits: for &t in traits_in_scope { let data = db.trait_data(t); // Traits annotated with `#[rustc_skip_array_during_method_dispatch]` are skipped during @@ -976,6 +967,43 @@ fn iterate_inherent_methods( ) -> ControlFlow<()> { let db = table.db; let env = table.trait_env.clone(); + + // For trait object types and placeholder types with trait bounds, the methods of the trait and + // its super traits are considered inherent methods. This matters because these methods have + // higher priority than the other traits' methods, which would be considered in + // `iterate_trait_method_candidates()` only after this function. + match self_ty.kind(Interner) { + TyKind::Placeholder(_) => { + let env = table.trait_env.clone(); + let traits = env + .traits_in_scope_from_clauses(self_ty.clone()) + .flat_map(|t| all_super_traits(db.upcast(), t)); + iterate_inherent_trait_methods( + self_ty, + table, + name, + receiver_ty, + receiver_adjustments.clone(), + callback, + traits, + )?; + } + TyKind::Dyn(_) => { + let principal_trait = self_ty.dyn_trait().unwrap(); + let traits = all_super_traits(db.upcast(), principal_trait); + iterate_inherent_trait_methods( + self_ty, + table, + name, + receiver_ty, + receiver_adjustments.clone(), + callback, + traits.into_iter(), + )?; + } + _ => {} + } + let def_crates = match def_crates(db, self_ty, env.krate) { Some(k) => k, None => return ControlFlow::Continue(()), @@ -987,23 +1015,6 @@ fn iterate_inherent_methods( VisibleFromModule::None => (None, None), }; - // For trait object types, methods of the trait and its super traits are considered inherent - // methods. This matters because these trait methods have higher priority than the other - // traits' methods, which would be considered in `iterate_trait_method_candidates()` after this - // function. - let inherent_traits = - self_ty.dyn_trait().into_iter().flat_map(|t| all_super_traits(db.upcast(), t)); - for t in inherent_traits { - let data = db.trait_data(t); - for &(_, item) in data.items.iter() { - // We don't pass `visible_from_module` as all trait items should be visible from the - // trait object. - if is_valid_candidate(table, name, receiver_ty, item, self_ty, None) { - callback(receiver_adjustments.clone().unwrap_or_default(), item)?; - } - } - } - if let Some(block_id) = block { if let Some(impls) = db.inherent_impls_in_block(block_id) { impls_for_self_ty( @@ -1034,6 +1045,28 @@ fn iterate_inherent_methods( } return ControlFlow::Continue(()); + fn iterate_inherent_trait_methods( + self_ty: &Ty, + table: &mut InferenceTable<'_>, + name: Option<&Name>, + receiver_ty: Option<&Ty>, + receiver_adjustments: Option<ReceiverAdjustments>, + callback: &mut dyn FnMut(ReceiverAdjustments, AssocItemId) -> ControlFlow<()>, + traits: impl Iterator<Item = TraitId>, + ) -> ControlFlow<()> { + let db = table.db; + for t in traits { + let data = db.trait_data(t); + for &(_, item) in data.items.iter() { + // We don't pass `visible_from_module` as all trait items should be visible. + if is_valid_candidate(table, name, receiver_ty, item, self_ty, None) { + callback(receiver_adjustments.clone().unwrap_or_default(), item)?; + } + } + } + ControlFlow::Continue(()) + } + fn impls_for_self_ty( impls: &InherentImpls, self_ty: &Ty, diff --git a/crates/hir-ty/src/tests/method_resolution.rs b/crates/hir-ty/src/tests/method_resolution.rs index fb2fc9369a..ac8edb841a 100644 --- a/crates/hir-ty/src/tests/method_resolution.rs +++ b/crates/hir-ty/src/tests/method_resolution.rs @@ -1236,6 +1236,23 @@ fn foo(a: &dyn Trait) { } #[test] +fn trait_method_priority_for_placeholder_type() { + check_types( + r#" +//- minicore: from +trait Trait { + fn into(&self) -> usize { 0 } +} + +fn foo<T: Trait>(a: &T) { + let _ = a.into(); + //^usize +} + "#, + ); +} + +#[test] fn autoderef_visibility_field() { check( r#" |