4 files changed, 21 insertions, 215 deletions

diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 109157a5e..6584bcf34 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -950,8 +950,7 @@ pub(crate) fn trait_environment_query(
                 traits_in_scope
                     .push((tr.self_type_parameter(&Interner).clone(), tr.hir_trait_id()));
             }
-            let program_clause: chalk_ir::ProgramClause<Interner> =
-                pred.clone().to_chalk(db).cast(&Interner);
+            let program_clause: chalk_ir::ProgramClause<Interner> = pred.clone().cast(&Interner);
             clauses.push(program_clause.into_from_env_clause(&Interner));
         }
     }
@@ -974,7 +973,7 @@ pub(crate) fn trait_environment_query(
         let substs = TyBuilder::type_params_subst(db, trait_id);
         let trait_ref = TraitRef { trait_id: to_chalk_trait_id(trait_id), substitution: substs };
         let pred = WhereClause::Implemented(trait_ref);
-        let program_clause: chalk_ir::ProgramClause<Interner> = pred.to_chalk(db).cast(&Interner);
+        let program_clause: chalk_ir::ProgramClause<Interner> = pred.cast(&Interner);
         clauses.push(program_clause.into_from_env_clause(&Interner));
     }
 
diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index de1d37e17..63d87fe61 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -96,7 +96,7 @@ pub(crate) fn trait_solve_query(
         }
     }
 
-    let canonical = goal.to_chalk(db).cast(&Interner);
+    let canonical = goal.cast(&Interner);
 
     // We currently don't deal with universes (I think / hope they're not yet
     // relevant for our use cases?)
diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index a5aa40c10..fcdcc2b4d 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -86,7 +86,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         debug!("impls_for_trait {:?}", trait_id);
         let trait_: hir_def::TraitId = from_chalk(self.db, trait_id);
 
-        let ty: Ty = from_chalk(self.db, parameters[0].assert_ty_ref(&Interner).clone());
+        let ty: Ty = parameters[0].assert_ty_ref(&Interner).clone();
 
         fn binder_kind(
             ty: &Ty,
@@ -187,15 +187,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
                 let (datas, binders) = (*datas).as_ref().into_value_and_skipped_binders();
                 let data = &datas.impl_traits[idx as usize];
                 let bound = OpaqueTyDatumBound {
-                    bounds: make_binders(
-                        data.bounds
-                            .skip_binders()
-                            .iter()
-                            .cloned()
-                            .map(|b| b.to_chalk(self.db))
-                            .collect(),
-                        1,
-                    ),
+                    bounds: make_binders(data.bounds.skip_binders().iter().cloned().collect(), 1),
                     where_clauses: make_binders(vec![], 0),
                 };
                 chalk_ir::Binders::new(binders, bound)
@@ -246,8 +238,8 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
                     let bound = OpaqueTyDatumBound {
                         bounds: make_binders(
                             vec![
-                                crate::wrap_empty_binders(impl_bound).to_chalk(self.db),
-                                crate::wrap_empty_binders(proj_bound).to_chalk(self.db),
+                                crate::wrap_empty_binders(impl_bound),
+                                crate::wrap_empty_binders(proj_bound),
                             ],
                             1,
                         ),
@@ -272,7 +264,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
 
     fn hidden_opaque_type(&self, _id: chalk_ir::OpaqueTyId<Interner>) -> chalk_ir::Ty<Interner> {
         // FIXME: actually provide the hidden type; it is relevant for auto traits
-        TyKind::Error.intern(&Interner).to_chalk(self.db)
+        TyKind::Error.intern(&Interner)
     }
 
     fn is_object_safe(&self, _trait_id: chalk_ir::TraitId<Interner>) -> bool {
@@ -293,12 +285,11 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         _closure_id: chalk_ir::ClosureId<Interner>,
         substs: &chalk_ir::Substitution<Interner>,
     ) -> chalk_ir::Binders<rust_ir::FnDefInputsAndOutputDatum<Interner>> {
-        let sig_ty: Ty =
-            from_chalk(self.db, substs.at(&Interner, 0).assert_ty_ref(&Interner).clone());
+        let sig_ty = substs.at(&Interner, 0).assert_ty_ref(&Interner).clone();
         let sig = &sig_ty.callable_sig(self.db).expect("first closure param should be fn ptr");
         let io = rust_ir::FnDefInputsAndOutputDatum {
-            argument_types: sig.params().iter().map(|ty| ty.clone().to_chalk(self.db)).collect(),
-            return_type: sig.ret().clone().to_chalk(self.db),
+            argument_types: sig.params().iter().cloned().collect(),
+            return_type: sig.ret().clone(),
         };
         make_binders(io.shifted_in(&Interner), 0)
     }
@@ -307,7 +298,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         _closure_id: chalk_ir::ClosureId<Interner>,
         _substs: &chalk_ir::Substitution<Interner>,
     ) -> chalk_ir::Binders<chalk_ir::Ty<Interner>> {
-        let ty = TyBuilder::unit().to_chalk(self.db);
+        let ty = TyBuilder::unit();
         make_binders(ty, 0)
     }
     fn closure_fn_substitution(
@@ -315,7 +306,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         _closure_id: chalk_ir::ClosureId<Interner>,
         _substs: &chalk_ir::Substitution<Interner>,
     ) -> chalk_ir::Substitution<Interner> {
-        Substitution::empty(&Interner).to_chalk(self.db)
+        Substitution::empty(&Interner)
     }
 
     fn trait_name(&self, trait_id: chalk_ir::TraitId<Interner>) -> String {
@@ -410,7 +401,7 @@ pub(crate) fn associated_ty_data_query(
     let where_clauses = convert_where_clauses(db, type_alias.into(), &bound_vars);
     let bound_data = rust_ir::AssociatedTyDatumBound { bounds, where_clauses };
     let datum = AssociatedTyDatum {
-        trait_id: trait_.to_chalk(db),
+        trait_id: to_chalk_trait_id(trait_),
         id,
         name: type_alias,
         binders: make_binders(bound_data, generic_params.len()),
@@ -563,7 +554,6 @@ fn impl_def_datum(
         trait_ref.display(db),
         where_clauses
     );
-    let trait_ref = trait_ref.to_chalk(db);
 
     let polarity = if negative { rust_ir::Polarity::Negative } else { rust_ir::Polarity::Positive };
 
@@ -624,7 +614,7 @@ fn type_alias_associated_ty_value(
         .associated_type_by_name(&type_alias_data.name)
         .expect("assoc ty value should not exist"); // validated when building the impl data as well
     let (ty, binders) = db.ty(type_alias.into()).into_value_and_skipped_binders();
-    let value_bound = rust_ir::AssociatedTyValueBound { ty: ty.to_chalk(db) };
+    let value_bound = rust_ir::AssociatedTyValueBound { ty };
     let value = rust_ir::AssociatedTyValue {
         impl_id: impl_id.to_chalk(db),
         associated_ty_id: to_assoc_type_id(assoc_ty),
@@ -647,8 +637,8 @@ pub(crate) fn fn_def_datum_query(
         // Note: Chalk doesn't actually use this information yet as far as I am aware, but we provide it anyway
         inputs_and_output: make_binders(
             rust_ir::FnDefInputsAndOutputDatum {
-                argument_types: sig.params().iter().map(|ty| ty.clone().to_chalk(db)).collect(),
-                return_type: sig.ret().clone().to_chalk(db),
+                argument_types: sig.params().iter().cloned().collect(),
+                return_type: sig.ret().clone(),
             }
             .shifted_in(&Interner),
             0,
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 62cf0fecf..54783b58c 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -18,55 +18,6 @@ use crate::{
 use super::interner::*;
 use super::*;
 
-impl ToChalk for Ty {
-    type Chalk = chalk_ir::Ty<Interner>;
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Ty<Interner> {
-        self
-    }
-    fn from_chalk(db: &dyn HirDatabase, chalk: chalk_ir::Ty<Interner>) -> Self {
-        chalk
-    }
-}
-
-impl ToChalk for GenericArg {
-    type Chalk = chalk_ir::GenericArg<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        self
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        chalk
-    }
-}
-
-impl ToChalk for Substitution {
-    type Chalk = chalk_ir::Substitution<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Substitution<Interner> {
-        self
-    }
-
-    fn from_chalk(
-        db: &dyn HirDatabase,
-        parameters: chalk_ir::Substitution<Interner>,
-    ) -> Substitution {
-        parameters
-    }
-}
-
-impl ToChalk for TraitRef {
-    type Chalk = chalk_ir::TraitRef<Interner>;
-
-    fn to_chalk(self: TraitRef, db: &dyn HirDatabase) -> chalk_ir::TraitRef<Interner> {
-        self
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, trait_ref: chalk_ir::TraitRef<Interner>) -> Self {
-        trait_ref
-    }
-}
-
 impl ToChalk for hir_def::TraitId {
     type Chalk = TraitId;
 
@@ -120,140 +71,6 @@ impl ToChalk for TypeAliasAsValue {
     }
 }
 
-impl ToChalk for WhereClause {
-    type Chalk = chalk_ir::WhereClause<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::WhereClause<Interner> {
-        self
-    }
-
-    fn from_chalk(
-        db: &dyn HirDatabase,
-        where_clause: chalk_ir::WhereClause<Interner>,
-    ) -> WhereClause {
-        where_clause
-    }
-}
-
-impl ToChalk for ProjectionTy {
-    type Chalk = chalk_ir::ProjectionTy<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::ProjectionTy<Interner> {
-        self
-    }
-
-    fn from_chalk(
-        db: &dyn HirDatabase,
-        projection_ty: chalk_ir::ProjectionTy<Interner>,
-    ) -> ProjectionTy {
-        projection_ty
-    }
-}
-impl ToChalk for OpaqueTy {
-    type Chalk = chalk_ir::OpaqueTy<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        self
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        chalk
-    }
-}
-
-impl ToChalk for AliasTy {
-    type Chalk = chalk_ir::AliasTy<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        self
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        chalk
-    }
-}
-
-impl ToChalk for AliasEq {
-    type Chalk = chalk_ir::AliasEq<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::AliasEq<Interner> {
-        self
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, alias_eq: chalk_ir::AliasEq<Interner>) -> Self {
-        alias_eq
-    }
-}
-
-impl ToChalk for DomainGoal {
-    type Chalk = chalk_ir::DomainGoal<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::DomainGoal<Interner> {
-        self
-    }
-
-    fn from_chalk(_db: &dyn HirDatabase, goal: chalk_ir::DomainGoal<Interner>) -> Self {
-        goal
-    }
-}
-
-impl<T> ToChalk for Canonical<T>
-where
-    T: HasInterner<Interner = Interner>,
-{
-    type Chalk = chalk_ir::Canonical<T>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Canonical<T> {
-        self
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, canonical: chalk_ir::Canonical<T>) -> Canonical<T> {
-        canonical
-    }
-}
-
-impl<T: ToChalk> ToChalk for InEnvironment<T>
-where
-    T: HasInterner<Interner = Interner>,
-{
-    type Chalk = chalk_ir::InEnvironment<T>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::InEnvironment<T> {
-        self
-    }
-
-    fn from_chalk(_db: &dyn HirDatabase, in_env: chalk_ir::InEnvironment<T>) -> InEnvironment<T> {
-        in_env
-    }
-}
-
-impl<T: ToChalk> ToChalk for crate::Binders<T>
-where
-    T: HasInterner<Interner = Interner>,
-{
-    type Chalk = chalk_ir::Binders<T>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Binders<T> {
-        self
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, binders: chalk_ir::Binders<T>) -> crate::Binders<T> {
-        binders
-    }
-}
-
-impl ToChalk for crate::ConstrainedSubst {
-    type Chalk = chalk_ir::ConstrainedSubst<Interner>;
-
-    fn to_chalk(self, _db: &dyn HirDatabase) -> Self::Chalk {
-        self
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        chalk
-    }
-}
-
 pub(super) fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T>
 where
     T: HasInterner<Interner = Interner>,
@@ -276,7 +93,7 @@ pub(super) fn convert_where_clauses(
     let generic_predicates = db.generic_predicates(def);
     let mut result = Vec::with_capacity(generic_predicates.len());
     for pred in generic_predicates.iter() {
-        result.push(pred.clone().substitute(&Interner, substs).to_chalk(db));
+        result.push(pred.clone().substitute(&Interner, substs));
     }
     result
 }
@@ -299,7 +116,7 @@ pub(super) fn generic_predicate_to_inline_bound(
             }
             let args_no_self = trait_ref.substitution.interned()[1..]
                 .iter()
-                .map(|ty| ty.clone().to_chalk(db).cast(&Interner))
+                .map(|ty| ty.clone().cast(&Interner))
                 .collect();
             let trait_bound = rust_ir::TraitBound { trait_id: trait_ref.trait_id, args_no_self };
             Some(chalk_ir::Binders::new(binders, rust_ir::InlineBound::TraitBound(trait_bound)))
@@ -311,10 +128,10 @@ pub(super) fn generic_predicate_to_inline_bound(
             let trait_ = projection_ty.trait_(db);
             let args_no_self = projection_ty.substitution.interned()[1..]
                 .iter()
-                .map(|ty| ty.clone().to_chalk(db).cast(&Interner))
+                .map(|ty| ty.clone().cast(&Interner))
                 .collect();
             let alias_eq_bound = rust_ir::AliasEqBound {
-                value: ty.clone().to_chalk(db),
+                value: ty.clone(),
                 trait_bound: rust_ir::TraitBound { trait_id: trait_.to_chalk(db), args_no_self },
                 associated_ty_id: projection_ty.associated_ty_id,
                 parameters: Vec::new(), // FIXME we don't support generic associated types yet