Merge #8356

8356: Align more methods to Chalk r=flodiebold a=flodiebold Related to #8313. Move some inherent methods that don't exist in Chalk to an extension trait, remove some others. Co-authored-by: Florian Diebold <[email protected]>
rust-lang · Apr 5, 2021 · 7ac1c8f · 7ac1c8f
2 parents 7278108 + d4a6a13
commit 7ac1c8f
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Showing 9 changed files with 87 additions and 90 deletions.
diff --git a/crates/hir_ty/src/autoderef.rs b/crates/hir_ty/src/autoderef.rs
@@ -13,7 +13,7 @@ use log::{info, warn};
 
 use crate::{
     db::HirDatabase, AliasEq, AliasTy, BoundVar, Canonical, CanonicalVarKinds, DebruijnIndex,
-    InEnvironment, Interner, Solution, Ty, TyBuilder, TyKind,
+    InEnvironment, Interner, ProjectionTyExt, Solution, Ty, TyBuilder, TyKind,
 };
 
 const AUTODEREF_RECURSION_LIMIT: usize = 10;

diff --git a/crates/hir_ty/src/chalk_ext.rs b/crates/hir_ty/src/chalk_ext.rs
@@ -1,6 +1,11 @@
 //! Various extensions traits for Chalk types.
 
-use crate::{Interner, Ty, TyKind};
+use hir_def::{AssocContainerId, Lookup, TraitId};
+
+use crate::{
+    db::HirDatabase, from_assoc_type_id, to_chalk_trait_id, Interner, ProjectionTy, TraitRef, Ty,
+    TyKind,
+};
 
 pub trait TyExt {
     fn is_unit(&self) -> bool;
@@ -11,3 +16,24 @@ impl TyExt for Ty {
         matches!(self.kind(&Interner), TyKind::Tuple(0, _))
     }
 }
+
+pub trait ProjectionTyExt {
+    fn trait_ref(&self, db: &dyn HirDatabase) -> TraitRef;
+    fn trait_(&self, db: &dyn HirDatabase) -> TraitId;
+}
+
+impl ProjectionTyExt for ProjectionTy {
+    fn trait_ref(&self, db: &dyn HirDatabase) -> TraitRef {
+        TraitRef {
+            trait_id: to_chalk_trait_id(self.trait_(db)),
+            substitution: self.substitution.clone(),
+        }
+    }
+
+    fn trait_(&self, db: &dyn HirDatabase) -> TraitId {
+        match from_assoc_type_id(self.associated_ty_id).lookup(db.upcast()).container {
+            AssocContainerId::TraitId(it) => it,
+            _ => panic!("projection ty without parent trait"),
+        }
+    }
+}
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
@@ -19,7 +19,8 @@ use crate::{
     db::HirDatabase, from_assoc_type_id, from_foreign_def_id, from_placeholder_idx, primitive,
     to_assoc_type_id, traits::chalk::from_chalk, utils::generics, AdtId, AliasEq, AliasTy,
     CallableDefId, CallableSig, DomainGoal, GenericArg, ImplTraitId, Interner, Lifetime, OpaqueTy,
-    ProjectionTy, QuantifiedWhereClause, Scalar, TraitRef, Ty, TyExt, TyKind, WhereClause,
+    ProjectionTy, ProjectionTyExt, QuantifiedWhereClause, Scalar, TraitRef, Ty, TyExt, TyKind,
+    WhereClause,
 };
 
 pub struct HirFormatter<'a> {

diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
@@ -22,8 +22,8 @@ use crate::{
     to_chalk_trait_id,
     traits::{chalk::from_chalk, FnTrait},
     utils::{generics, variant_data, Generics},
-    AdtId, Binders, CallableDefId, FnPointer, FnSig, InEnvironment, Interner, Rawness, Scalar,
-    Substitution, TraitRef, Ty, TyBuilder, TyKind,
+    AdtId, Binders, CallableDefId, FnPointer, FnSig, InEnvironment, Interner, ProjectionTyExt,
+    Rawness, Scalar, Substitution, TraitRef, Ty, TyBuilder, TyKind,
 };
 
 use super::{
@@ -180,7 +180,8 @@ impl<'a> InferenceContext<'a> {
                 let inner_ty = self.infer_expr(*body, &Expectation::none());
                 let impl_trait_id = crate::ImplTraitId::AsyncBlockTypeImplTrait(self.owner, *body);
                 let opaque_ty_id = self.db.intern_impl_trait_id(impl_trait_id).into();
-                TyKind::OpaqueType(opaque_ty_id, Substitution::single(inner_ty)).intern(&Interner)
+                TyKind::OpaqueType(opaque_ty_id, Substitution::from1(&Interner, inner_ty))
+                    .intern(&Interner)
             }
             Expr::Loop { body, label } => {
                 self.breakables.push(BreakableContext {
@@ -266,7 +267,8 @@ impl<'a> InferenceContext<'a> {
                 .intern(&Interner);
                 let closure_id = self.db.intern_closure((self.owner, tgt_expr)).into();
                 let closure_ty =
-                    TyKind::Closure(closure_id, Substitution::single(sig_ty)).intern(&Interner);
+                    TyKind::Closure(closure_id, Substitution::from1(&Interner, sig_ty))
+                        .intern(&Interner);
 
                 // Eagerly try to relate the closure type with the expected
                 // type, otherwise we often won't have enough information to

diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
@@ -30,8 +30,8 @@ mod test_db;
 
 use std::sync::Arc;
 
+use chalk_ext::ProjectionTyExt;
 use itertools::Itertools;
-use smallvec::SmallVec;
 
 use base_db::salsa;
 use hir_def::{
@@ -49,16 +49,14 @@ pub use lower::{
     associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode,
     TyDefId, TyLoweringContext, ValueTyDefId,
 };
-pub use traits::TraitEnvironment;
+pub use traits::{chalk::Interner, TraitEnvironment};
 pub use types::*;
 pub use walk::TypeWalk;
 
 pub use chalk_ir::{
     cast::Cast, AdtId, BoundVar, DebruijnIndex, Mutability, Safety, Scalar, TyVariableKind,
 };
 
-pub use crate::traits::chalk::Interner;
-
 pub type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
 pub type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
 pub type FnDefId = chalk_ir::FnDefId<Interner>;
@@ -72,37 +70,9 @@ pub type CanonicalVarKinds = chalk_ir::CanonicalVarKinds<Interner>;
 
 pub type ChalkTraitId = chalk_ir::TraitId<Interner>;
 
-impl ProjectionTy {
-    pub fn trait_ref(&self, db: &dyn HirDatabase) -> TraitRef {
-        TraitRef {
-            trait_id: to_chalk_trait_id(self.trait_(db)),
-            substitution: self.substitution.clone(),
-        }
-    }
-
-    pub fn self_type_parameter(&self, interner: &Interner) -> &Ty {
-        &self.substitution.interned()[0].assert_ty_ref(interner)
-    }
-
-    fn trait_(&self, db: &dyn HirDatabase) -> TraitId {
-        match from_assoc_type_id(self.associated_ty_id).lookup(db.upcast()).container {
-            AssocContainerId::TraitId(it) => it,
-            _ => panic!("projection ty without parent trait"),
-        }
-    }
-}
-
 pub type FnSig = chalk_ir::FnSig<Interner>;
 
 impl Substitution {
-    pub fn single(ty: Ty) -> Substitution {
-        Substitution::intern({
-            let mut v = SmallVec::new();
-            v.push(ty.cast(&Interner));
-            v
-        })
-    }
-
     pub fn prefix(&self, n: usize) -> Substitution {
         Substitution::intern(self.interned()[..std::cmp::min(self.len(&Interner), n)].into())
     }
@@ -119,22 +89,11 @@ pub fn param_idx(db: &dyn HirDatabase, id: TypeParamId) -> Option<usize> {
     generics(db.upcast(), id.parent).param_idx(id)
 }
 
-impl<T> Binders<T> {
-    pub fn wrap_empty(value: T) -> Self
-    where
-        T: TypeWalk,
-    {
-        Binders::empty(&Interner, value.shifted_in_from(DebruijnIndex::ONE))
-    }
-}
-
-impl<T: TypeWalk> Binders<T> {
-    /// Substitutes all variables.
-    pub fn substitute(self, interner: &Interner, subst: &Substitution) -> T {
-        let (value, binders) = self.into_value_and_skipped_binders();
-        assert_eq!(subst.len(interner), binders.len(interner));
-        value.subst_bound_vars(subst)
-    }
+pub fn wrap_empty_binders<T>(value: T) -> Binders<T>
+where
+    T: TypeWalk,
+{
+    Binders::empty(&Interner, value.shifted_in_from(DebruijnIndex::ONE))
 }
 
 pub fn make_only_type_binders<T>(num_vars: usize, value: T) -> Binders<T> {
@@ -149,31 +108,11 @@ pub fn make_only_type_binders<T>(num_vars: usize, value: T) -> Binders<T> {
 }
 
 impl TraitRef {
-    pub fn self_type_parameter(&self, interner: &Interner) -> &Ty {
-        &self.substitution.at(interner, 0).assert_ty_ref(interner)
-    }
-
     pub fn hir_trait_id(&self) -> TraitId {
         from_chalk_trait_id(self.trait_id)
     }
 }
 
-impl WhereClause {
-    pub fn is_implemented(&self) -> bool {
-        matches!(self, WhereClause::Implemented(_))
-    }
-
-    pub fn trait_ref(&self, db: &dyn HirDatabase) -> Option<TraitRef> {
-        match self {
-            WhereClause::Implemented(tr) => Some(tr.clone()),
-            WhereClause::AliasEq(AliasEq { alias: AliasTy::Projection(proj), .. }) => {
-                Some(proj.trait_ref(db))
-            }
-            WhereClause::AliasEq(_) => None,
-        }
-    }
-}
-
 impl<T> Canonical<T> {
     pub fn new(value: T, kinds: impl IntoIterator<Item = TyVariableKind>) -> Self {
         let kinds = kinds.into_iter().map(|tk| {

diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
@@ -384,7 +384,9 @@ impl<'a> TyLoweringContext<'a> {
                             1,
                             QuantifiedWhereClauses::from_iter(
                                 &Interner,
-                                Some(Binders::wrap_empty(WhereClause::Implemented(trait_ref))),
+                                Some(crate::wrap_empty_binders(WhereClause::Implemented(
+                                    trait_ref,
+                                ))),
                             ),
                         ),
                     };
@@ -720,7 +722,7 @@ impl<'a> TyLoweringContext<'a> {
         let trait_ref = match bound {
             TypeBound::Path(path) => {
                 bindings = self.lower_trait_ref_from_path(path, Some(self_ty));
-                bindings.clone().map(WhereClause::Implemented).map(|b| Binders::wrap_empty(b))
+                bindings.clone().map(WhereClause::Implemented).map(|b| crate::wrap_empty_binders(b))
             }
             TypeBound::Lifetime(_) => None,
             TypeBound::Error => None,
@@ -767,7 +769,7 @@ impl<'a> TyLoweringContext<'a> {
                     let ty = self.lower_ty(type_ref);
                     let alias_eq =
                         AliasEq { alias: AliasTy::Projection(projection_ty.clone()), ty };
-                    preds.push(Binders::wrap_empty(WhereClause::AliasEq(alias_eq)));
+                    preds.push(crate::wrap_empty_binders(WhereClause::AliasEq(alias_eq)));
                 }
                 for bound in &binding.bounds {
                     preds.extend(self.lower_type_bound(

diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
@@ -220,7 +220,8 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
                     let impl_bound = WhereClause::Implemented(TraitRef {
                         trait_id: to_chalk_trait_id(future_trait),
                         // Self type as the first parameter.
-                        substitution: Substitution::single(
+                        substitution: Substitution::from1(
+                            &Interner,
                             TyKind::BoundVar(BoundVar {
                                 debruijn: DebruijnIndex::INNERMOST,
                                 index: 0,
@@ -232,7 +233,8 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
                         alias: AliasTy::Projection(ProjectionTy {
                             associated_ty_id: to_assoc_type_id(future_output),
                             // Self type as the first parameter.
-                            substitution: Substitution::single(
+                            substitution: Substitution::from1(
+                                &Interner,
                                 TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0))
                                     .intern(&Interner),
                             ),
@@ -244,8 +246,8 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
                     let bound = OpaqueTyDatumBound {
                         bounds: make_binders(
                             vec![
-                                wrap_in_empty_binders(impl_bound).to_chalk(self.db),
-                                wrap_in_empty_binders(proj_bound).to_chalk(self.db),
+                                crate::wrap_empty_binders(impl_bound).to_chalk(self.db),
+                                crate::wrap_empty_binders(proj_bound).to_chalk(self.db),
                             ],
                             1,
                         ),
@@ -721,7 +723,3 @@ impl From<crate::db::InternedClosureId> for chalk_ir::ClosureId<Interner> {
         chalk_ir::ClosureId(id.as_intern_id())
     }
 }
-
-fn wrap_in_empty_binders<T: crate::TypeWalk>(value: T) -> crate::Binders<T> {
-    crate::Binders::wrap_empty(value)
-}
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -10,9 +10,9 @@ use base_db::salsa::InternKey;
 use hir_def::{GenericDefId, TypeAliasId};
 
 use crate::{
-    db::HirDatabase, primitive::UintTy, AliasTy, CallableDefId, Canonical, DomainGoal, FnPointer,
-    GenericArg, InEnvironment, OpaqueTy, ProjectionTy, QuantifiedWhereClause, Scalar, Substitution,
-    TraitRef, Ty, TypeWalk, WhereClause,
+    chalk_ext::ProjectionTyExt, db::HirDatabase, primitive::UintTy, AliasTy, CallableDefId,
+    Canonical, DomainGoal, FnPointer, GenericArg, InEnvironment, OpaqueTy, ProjectionTy,
+    QuantifiedWhereClause, Scalar, Substitution, TraitRef, Ty, TypeWalk, WhereClause,
 };
 
 use super::interner::*;

diff --git a/crates/hir_ty/src/types.rs b/crates/hir_ty/src/types.rs
@@ -4,7 +4,7 @@
 use std::sync::Arc;
 
 use chalk_ir::{
-    cast::{CastTo, Caster},
+    cast::{Cast, CastTo, Caster},
     BoundVar, Mutability, Scalar, TyVariableKind,
 };
 use hir_def::LifetimeParamId;
@@ -36,6 +36,12 @@ pub struct ProjectionTy {
     pub substitution: Substitution,
 }
 
+impl ProjectionTy {
+    pub fn self_type_parameter(&self, interner: &Interner) -> &Ty {
+        &self.substitution.interned()[0].assert_ty_ref(interner)
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
 pub struct DynTy {
     /// The unknown self type.
@@ -279,6 +285,14 @@ impl Substitution {
         self.0.iter()
     }
 
+    pub fn from1(_interner: &Interner, ty: Ty) -> Substitution {
+        Substitution::intern({
+            let mut v = SmallVec::new();
+            v.push(ty.cast(&Interner));
+            v
+        })
+    }
+
     pub fn from_iter(
         interner: &Interner,
         elements: impl IntoIterator<Item = impl CastTo<GenericArg>>,
@@ -353,6 +367,15 @@ impl<T: Clone> Binders<&T> {
     }
 }
 
+impl<T: TypeWalk> Binders<T> {
+    /// Substitutes all variables.
+    pub fn substitute(self, interner: &Interner, subst: &Substitution) -> T {
+        let (value, binders) = self.into_value_and_skipped_binders();
+        assert_eq!(subst.len(interner), binders.len(interner));
+        value.subst_bound_vars(subst)
+    }
+}
+
 impl<T: std::fmt::Debug> std::fmt::Debug for Binders<T> {
     fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
         let Binders { ref binders, ref value } = *self;
@@ -368,6 +391,12 @@ pub struct TraitRef {
     pub substitution: Substitution,
 }
 
+impl TraitRef {
+    pub fn self_type_parameter(&self, interner: &Interner) -> &Ty {
+        &self.substitution.at(interner, 0).assert_ty_ref(interner)
+    }
+}
+
 /// Like `generics::WherePredicate`, but with resolved types: A condition on the
 /// parameters of a generic item.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]