Align InEnvironment with Chalk

This in particular means storing a chalk_ir::Environment, not our
TraitEnvironment. This makes InEnvironment not usable for Type, where we
need to keep the full TraitEnvironment.

8 files changed, 38 insertions, 45 deletions

diff --git a/crates/hir_ty/src/autoderef.rs b/crates/hir_ty/src/autoderef.rs
index d6f0553b1..dc5fc759a 100644
--- a/crates/hir_ty/src/autoderef.rs
+++ b/crates/hir_ty/src/autoderef.rs
@@ -27,9 +27,9 @@ pub fn autoderef<'a>(
     krate: Option<CrateId>,
     ty: InEnvironment<Canonical<Ty>>,
 ) -> impl Iterator<Item = Canonical<Ty>> + 'a {
-    let InEnvironment { value: ty, environment } = ty;
+    let InEnvironment { goal: ty, environment } = ty;
     successors(Some(ty), move |ty| {
-        deref(db, krate?, InEnvironment { value: ty, environment: environment.clone() })
+        deref(db, krate?, InEnvironment { goal: ty, environment: environment.clone() })
     })
     .take(AUTODEREF_RECURSION_LIMIT)
 }
@@ -39,8 +39,8 @@ pub(crate) fn deref(
     krate: CrateId,
     ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
-    if let Some(derefed) = ty.value.value.builtin_deref() {
-        Some(Canonical { value: derefed, binders: ty.value.binders.clone() })
+    if let Some(derefed) = ty.goal.value.builtin_deref() {
+        Some(Canonical { value: derefed, binders: ty.goal.binders.clone() })
     } else {
         deref_by_trait(db, krate, ty)
     }
@@ -67,15 +67,15 @@ fn deref_by_trait(
     // FIXME make the Canonical / bound var handling nicer
 
     let parameters =
-        Substitution::build_for_generics(&generic_params).push(ty.value.value.clone()).build();
+        Substitution::build_for_generics(&generic_params).push(ty.goal.value.clone()).build();
 
     // Check that the type implements Deref at all
     let trait_ref =
         TraitRef { trait_id: to_chalk_trait_id(deref_trait), substitution: parameters.clone() };
     let implements_goal = Canonical {
-        binders: ty.value.binders.clone(),
+        binders: ty.goal.binders.clone(),
         value: InEnvironment {
-            value: trait_ref.cast(&Interner),
+            goal: trait_ref.cast(&Interner),
             environment: ty.environment.clone(),
         },
     };
@@ -91,20 +91,20 @@ fn deref_by_trait(
         }),
         ty: TyKind::BoundVar(BoundVar::new(
             DebruijnIndex::INNERMOST,
-            ty.value.binders.len(&Interner),
+            ty.goal.binders.len(&Interner),
         ))
         .intern(&Interner),
     };
 
     let obligation = projection.cast(&Interner);
 
-    let in_env = InEnvironment { value: obligation, environment: ty.environment };
+    let in_env = InEnvironment { goal: obligation, environment: ty.environment };
 
     let canonical = Canonical {
         value: in_env,
         binders: CanonicalVarKinds::from_iter(
             &Interner,
-            ty.value.binders.iter(&Interner).cloned().chain(Some(chalk_ir::WithKind::new(
+            ty.goal.binders.iter(&Interner).cloned().chain(Some(chalk_ir::WithKind::new(
                 chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General),
                 chalk_ir::UniverseIndex::ROOT,
             ))),
@@ -134,7 +134,7 @@ fn deref_by_trait(
                 if vars.0.value[i - 1].interned(&Interner)
                     != &TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, i - 1))
                 {
-                    warn!("complex solution for derefing {:?}: {:?}, ignoring", ty.value, solution);
+                    warn!("complex solution for derefing {:?}: {:?}, ignoring", ty.goal, solution);
                     return None;
                 }
             }
@@ -144,7 +144,7 @@ fn deref_by_trait(
             })
         }
         Solution::Ambig(_) => {
-            info!("Ambiguous solution for derefing {:?}: {:?}", ty.value, solution);
+            info!("Ambiguous solution for derefing {:?}: {:?}", ty.goal, solution);
             None
         }
     }
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs
index b9e434c78..8f9cf7480 100644
--- a/crates/hir_ty/src/infer.rs
+++ b/crates/hir_ty/src/infer.rs
@@ -331,7 +331,7 @@ impl<'a> InferenceContext<'a> {
     fn resolve_obligations_as_possible(&mut self) {
         let obligations = mem::replace(&mut self.obligations, Vec::new());
         for obligation in obligations {
-            let in_env = InEnvironment::new(self.trait_env.clone(), obligation.clone());
+            let in_env = InEnvironment::new(self.trait_env.env.clone(), obligation.clone());
             let canonicalized = self.canonicalizer().canonicalize_obligation(in_env);
             let solution =
                 self.db.trait_solve(self.resolver.krate().unwrap(), canonicalized.value.clone());
diff --git a/crates/hir_ty/src/infer/coerce.rs b/crates/hir_ty/src/infer/coerce.rs
index 07eb96573..9c62932b1 100644
--- a/crates/hir_ty/src/infer/coerce.rs
+++ b/crates/hir_ty/src/infer/coerce.rs
@@ -142,7 +142,7 @@ impl<'a> InferenceContext<'a> {
             .build();
         let trait_ref =
             TraitRef { trait_id: to_chalk_trait_id(coerce_unsized_trait), substitution: substs };
-        let goal = InEnvironment::new(self.trait_env.clone(), trait_ref.cast(&Interner));
+        let goal = InEnvironment::new(self.trait_env.env.clone(), trait_ref.cast(&Interner));
 
         let canonicalizer = self.canonicalizer();
         let canonicalized = canonicalizer.canonicalize_obligation(goal);
@@ -170,8 +170,8 @@ impl<'a> InferenceContext<'a> {
             self.db,
             self.resolver.krate(),
             InEnvironment {
-                value: canonicalized.value.clone(),
-                environment: self.trait_env.clone(),
+                goal: canonicalized.value.clone(),
+                environment: self.trait_env.env.clone(),
             },
         ) {
             let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value);
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 17849d552..4e2a432ed 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -90,12 +90,12 @@ impl<'a> InferenceContext<'a> {
         let substs =
             Substitution::build_for_generics(&generic_params).push(ty.clone()).push(arg_ty).build();
 
-        let trait_env = Arc::clone(&self.trait_env);
+        let trait_env = self.trait_env.env.clone();
         let implements_fn_trait: DomainGoal =
             TraitRef { trait_id: to_chalk_trait_id(fn_once_trait), substitution: substs.clone() }
                 .cast(&Interner);
         let goal = self.canonicalizer().canonicalize_obligation(InEnvironment {
-            value: implements_fn_trait.clone(),
+            goal: implements_fn_trait.clone(),
             environment: trait_env,
         });
         if self.db.trait_solve(krate, goal.value).is_some() {
@@ -299,8 +299,8 @@ impl<'a> InferenceContext<'a> {
                     self.db,
                     self.resolver.krate(),
                     InEnvironment {
-                        value: canonicalized.value.clone(),
-                        environment: self.trait_env.clone(),
+                        goal: canonicalized.value.clone(),
+                        environment: self.trait_env.env.clone(),
                     },
                 );
                 let (param_tys, ret_ty): (Vec<Ty>, Ty) = derefs
@@ -438,8 +438,8 @@ impl<'a> InferenceContext<'a> {
                     self.db,
                     self.resolver.krate(),
                     InEnvironment {
-                        value: canonicalized.value.clone(),
-                        environment: self.trait_env.clone(),
+                        goal: canonicalized.value.clone(),
+                        environment: self.trait_env.env.clone(),
                     },
                 )
                 .find_map(|derefed_ty| {
@@ -538,8 +538,8 @@ impl<'a> InferenceContext<'a> {
                                 self.db,
                                 krate,
                                 InEnvironment {
-                                    value: &canonicalized.value,
-                                    environment: self.trait_env.clone(),
+                                    goal: &canonicalized.value,
+                                    environment: self.trait_env.env.clone(),
                                 },
                             ) {
                                 Some(derefed_ty) => {
diff --git a/crates/hir_ty/src/infer/unify.rs b/crates/hir_ty/src/infer/unify.rs
index 7595b46cf..75250a369 100644
--- a/crates/hir_ty/src/infer/unify.rs
+++ b/crates/hir_ty/src/infer/unify.rs
@@ -98,15 +98,12 @@ impl<'a, 'b> Canonicalizer<'a, 'b> {
         mut self,
         obligation: InEnvironment<DomainGoal>,
     ) -> Canonicalized<InEnvironment<DomainGoal>> {
-        let result = match obligation.value {
+        let result = match obligation.goal {
             DomainGoal::Holds(wc) => {
                 DomainGoal::Holds(self.do_canonicalize(wc, DebruijnIndex::INNERMOST))
             }
         };
-        self.into_canonicalized(InEnvironment {
-            value: result,
-            environment: obligation.environment,
-        })
+        self.into_canonicalized(InEnvironment { goal: result, environment: obligation.environment })
     }
 }
 
diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs
index 0abe8f0a3..8e986ddde 100644
--- a/crates/hir_ty/src/method_resolution.rs
+++ b/crates/hir_ty/src/method_resolution.rs
@@ -376,7 +376,7 @@ fn iterate_method_candidates_impl(
             // Also note that when we've got a receiver like &S, even if the method we
             // find in the end takes &self, we still do the autoderef step (just as
             // rustc does an autoderef and then autoref again).
-            let ty = InEnvironment { value: ty.clone(), environment: env.clone() };
+            let ty = InEnvironment { goal: ty.clone(), environment: env.env.clone() };
 
             // We have to be careful about the order we're looking at candidates
             // in here. Consider the case where we're resolving `x.clone()`
@@ -622,7 +622,7 @@ pub fn resolve_indexing_op(
     krate: CrateId,
     index_trait: TraitId,
 ) -> Option<Canonical<Ty>> {
-    let ty = InEnvironment { value: ty.clone(), environment: env.clone() };
+    let ty = InEnvironment { goal: ty.clone(), environment: env.env.clone() };
     let deref_chain = autoderef_method_receiver(db, krate, ty);
     for ty in deref_chain {
         let goal = generic_implements_goal(db, env.clone(), index_trait, ty.clone());
@@ -794,7 +794,7 @@ fn generic_implements_goal(
     let obligation = trait_ref.cast(&Interner);
     Canonical {
         binders: CanonicalVarKinds::from_iter(&Interner, kinds),
-        value: InEnvironment::new(env, obligation),
+        value: InEnvironment::new(env.env.clone(), obligation),
     }
 }
 
diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index 7dadd1ffb..ccee0e5ad 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -1,6 +1,5 @@
 //! Trait solving using Chalk.
 use std::env::var;
-use std::sync::Arc;
 
 use base_db::CrateId;
 use chalk_ir::cast::Cast;
@@ -44,7 +43,7 @@ pub struct TraitEnvironment {
     // When we're using Chalk's Ty we can make this a BTreeMap since it's Ord,
     // but for now it's too annoying...
     pub(crate) traits_from_clauses: Vec<(Ty, TraitId)>,
-    pub(crate) env: chalk_ir::Environment<Interner>,
+    pub env: chalk_ir::Environment<Interner>,
 }
 
 impl TraitEnvironment {
@@ -74,13 +73,13 @@ impl Default for TraitEnvironment {
 /// Something (usually a goal), along with an environment.
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct InEnvironment<T> {
-    pub environment: Arc<TraitEnvironment>,
-    pub value: T,
+    pub environment: chalk_ir::Environment<Interner>,
+    pub goal: T,
 }
 
 impl<T> InEnvironment<T> {
-    pub fn new(environment: Arc<TraitEnvironment>, value: T) -> InEnvironment<T> {
-        InEnvironment { environment, value }
+    pub fn new(environment: chalk_ir::Environment<Interner>, value: T) -> InEnvironment<T> {
+        InEnvironment { environment, goal: value }
     }
 }
 
@@ -126,18 +125,18 @@ pub(crate) fn trait_solve_query(
     krate: CrateId,
     goal: Canonical<InEnvironment<DomainGoal>>,
 ) -> Option<Solution> {
-    let _p = profile::span("trait_solve_query").detail(|| match &goal.value.value {
+    let _p = profile::span("trait_solve_query").detail(|| match &goal.value.goal {
         DomainGoal::Holds(WhereClause::Implemented(it)) => {
             db.trait_data(it.hir_trait_id()).name.to_string()
         }
         DomainGoal::Holds(WhereClause::AliasEq(_)) => "alias_eq".to_string(),
     });
-    log::info!("trait_solve_query({})", goal.value.value.display(db));
+    log::info!("trait_solve_query({})", goal.value.goal.display(db));
 
     if let DomainGoal::Holds(WhereClause::AliasEq(AliasEq {
         alias: AliasTy::Projection(projection_ty),
         ..
-    })) = &goal.value.value
+    })) = &goal.value.goal
     {
         if let TyKind::BoundVar(_) = &projection_ty.substitution[0].interned(&Interner) {
             // Hack: don't ask Chalk to normalize with an unknown self type, it'll say that's impossible
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 58d8f2894..aef6b8a15 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -455,10 +455,7 @@ where
     type Chalk = chalk_ir::InEnvironment<T::Chalk>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::InEnvironment<T::Chalk> {
-        chalk_ir::InEnvironment {
-            environment: self.environment.env.clone(),
-            goal: self.value.to_chalk(db),
-        }
+        chalk_ir::InEnvironment { environment: self.environment, goal: self.goal.to_chalk(db) }
     }
 
     fn from_chalk(