diff options
Diffstat (limited to 'src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs')
| -rw-r--r-- | src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs | 134 |
1 files changed, 107 insertions, 27 deletions
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs b/src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs index f3a5f69b2..041d61c1b 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs @@ -27,8 +27,9 @@ use crate::{ primitive::{FloatTy, IntTy, UintTy}, static_lifetime, to_chalk_trait_id, utils::all_super_traits, - AdtId, Canonical, CanonicalVarKinds, DebruijnIndex, DynTyExt, ForeignDefId, InEnvironment, - Interner, Scalar, Substitution, TraitEnvironment, TraitRef, TraitRefExt, Ty, TyBuilder, TyExt, + AdtId, Canonical, CanonicalVarKinds, DebruijnIndex, DynTyExt, ForeignDefId, Goal, Guidance, + InEnvironment, Interner, Scalar, Solution, Substitution, TraitEnvironment, TraitRef, + TraitRefExt, Ty, TyBuilder, TyExt, }; /// This is used as a key for indexing impls. @@ -167,12 +168,9 @@ impl TraitImpls { ) -> Arc<[Arc<Self>]> { let _p = profile::span("trait_impls_in_deps_query").detail(|| format!("{krate:?}")); let crate_graph = db.crate_graph(); - // FIXME: use `Arc::from_iter` when it becomes available - Arc::from( - crate_graph - .transitive_deps(krate) - .map(|krate| db.trait_impls_in_crate(krate)) - .collect::<Vec<_>>(), + + Arc::from_iter( + crate_graph.transitive_deps(krate).map(|krate| db.trait_impls_in_crate(krate)), ) } @@ -862,6 +860,62 @@ fn is_inherent_impl_coherent( } } +/// Checks whether the impl satisfies the orphan rules. +/// +/// Given `impl<P1..=Pn> Trait<T1..=Tn> for T0`, an `impl`` is valid only if at least one of the following is true: +/// - Trait is a local trait +/// - All of +/// - At least one of the types `T0..=Tn`` must be a local type. Let `Ti`` be the first such type. +/// - No uncovered type parameters `P1..=Pn` may appear in `T0..Ti`` (excluding `Ti`) +pub fn check_orphan_rules(db: &dyn HirDatabase, impl_: ImplId) -> bool { + let substs = TyBuilder::placeholder_subst(db, impl_); + let Some(impl_trait) = db.impl_trait(impl_) else { + // not a trait impl + return true; + }; + + let local_crate = impl_.lookup(db.upcast()).container.krate(); + let is_local = |tgt_crate| tgt_crate == local_crate; + + let trait_ref = impl_trait.substitute(Interner, &substs); + let trait_id = from_chalk_trait_id(trait_ref.trait_id); + if is_local(trait_id.module(db.upcast()).krate()) { + // trait to be implemented is local + return true; + } + + let unwrap_fundamental = |ty: Ty| match ty.kind(Interner) { + TyKind::Ref(_, _, referenced) => referenced.clone(), + &TyKind::Adt(AdtId(hir_def::AdtId::StructId(s)), ref subs) => { + let struct_data = db.struct_data(s); + if struct_data.flags.contains(StructFlags::IS_FUNDAMENTAL) { + let next = subs.type_parameters(Interner).next(); + match next { + Some(ty) => ty, + None => ty, + } + } else { + ty + } + } + _ => ty, + }; + // - At least one of the types `T0..=Tn`` must be a local type. Let `Ti`` be the first such type. + let is_not_orphan = trait_ref.substitution.type_parameters(Interner).any(|ty| { + match unwrap_fundamental(ty).kind(Interner) { + &TyKind::Adt(AdtId(id), _) => is_local(id.module(db.upcast()).krate()), + TyKind::Error => true, + TyKind::Dyn(it) => it.principal().map_or(false, |trait_ref| { + is_local(from_chalk_trait_id(trait_ref.trait_id).module(db.upcast()).krate()) + }), + _ => false, + } + }); + // FIXME: param coverage + // - No uncovered type parameters `P1..=Pn` may appear in `T0..Ti`` (excluding `Ti`) + is_not_orphan +} + pub fn iterate_path_candidates( ty: &Canonical<Ty>, db: &dyn HirDatabase, @@ -1422,26 +1476,52 @@ fn is_valid_fn_candidate( // We need to consider the bounds on the impl to distinguish functions of the same name // for a type. let predicates = db.generic_predicates(impl_id.into()); - let valid = predicates - .iter() - .map(|predicate| { - let (p, b) = predicate - .clone() - .substitute(Interner, &impl_subst) - // Skipping the inner binders is ok, as we don't handle quantified where - // clauses yet. - .into_value_and_skipped_binders(); - stdx::always!(b.len(Interner) == 0); - p - }) - // It's ok to get ambiguity here, as we may not have enough information to prove - // obligations. We'll check if the user is calling the selected method properly - // later anyway. - .all(|p| table.try_obligation(p.cast(Interner)).is_some()); - match valid { - true => IsValidCandidate::Yes, - false => IsValidCandidate::No, + let goals = predicates.iter().map(|p| { + let (p, b) = p + .clone() + .substitute(Interner, &impl_subst) + // Skipping the inner binders is ok, as we don't handle quantified where + // clauses yet. + .into_value_and_skipped_binders(); + stdx::always!(b.len(Interner) == 0); + + p.cast::<Goal>(Interner) + }); + + for goal in goals.clone() { + let in_env = InEnvironment::new(&table.trait_env.env, goal); + let canonicalized = table.canonicalize(in_env); + let solution = table.db.trait_solve( + table.trait_env.krate, + table.trait_env.block, + canonicalized.value.clone(), + ); + + match solution { + Some(Solution::Unique(canonical_subst)) => { + canonicalized.apply_solution( + table, + Canonical { + binders: canonical_subst.binders, + value: canonical_subst.value.subst, + }, + ); + } + Some(Solution::Ambig(Guidance::Definite(substs))) => { + canonicalized.apply_solution(table, substs); + } + Some(_) => (), + None => return IsValidCandidate::No, + } } + + for goal in goals { + if table.try_obligation(goal).is_none() { + return IsValidCandidate::No; + } + } + + IsValidCandidate::Yes } else { // For `ItemContainerId::TraitId`, we check if `self_ty` implements the trait in // `iterate_trait_method_candidates()`. |