Store object safety knowledge in Program instead of TraitDatum

Author: AzureMarker

chalk-integration/src/lowering.rs

@@ -10,7 +10,7 @@ use chalk_rust_ir as rust_ir;
 use chalk_rust_ir::{
     Anonymize, AssociatedTyValueId, IntoWhereClauses, OpaqueTyDatum, OpaqueTyDatumBound,
 };
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, HashSet};
 use std::sync::Arc;
 use string_cache::DefaultAtom as Atom;
 
@@ -243,6 +243,7 @@ impl LowerProgram for Program {
         let mut struct_kinds = BTreeMap::new();
         let mut trait_kinds = BTreeMap::new();
         let mut opaque_ty_kinds = BTreeMap::new();
+        let mut object_safe_traits = HashSet::new();
         for (item, &raw_id) in self.items.iter().zip(&raw_ids) {
             match item {
                 Item::StructDefn(defn) => {
@@ -256,6 +257,10 @@ impl LowerProgram for Program {
                     let id = TraitId(raw_id);
                     trait_ids.insert(type_kind.name.clone(), id);
                     trait_kinds.insert(id, type_kind);
+
+                    if defn.flags.object_safe {
+                        object_safe_traits.insert(id);
+                    }
                 }
                 Item::OpaqueTyDefn(defn) => {
                     let type_kind = defn.lower_type_kind()?;
@@ -457,6 +462,7 @@ impl LowerProgram for Program {
             opaque_ty_kinds,
             opaque_ty_data,
             custom_clauses,
+            object_safe_traits,
         };
 
         Ok(program)
@@ -1019,7 +1025,6 @@ impl LowerTraitFlags for TraitFlags {
             fundamental: self.fundamental,
             non_enumerable: self.non_enumerable,
             coinductive: self.coinductive,
-            object_safe: self.object_safe,
         }
     }
 }

chalk-integration/src/program.rs

@@ -13,7 +13,7 @@ use chalk_rust_ir::{
 };
 use chalk_solve::split::Split;
 use chalk_solve::RustIrDatabase;
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, HashSet};
 use std::fmt;
 use std::sync::Arc;
 
@@ -61,6 +61,9 @@ pub struct Program {
 
     /// For each user-specified clause
     pub custom_clauses: Vec<ProgramClause<ChalkIr>>,
+
+    /// Store the traits marked with `#[object_safe]`
+    pub object_safe_traits: HashSet<TraitId<ChalkIr>>,
 }
 
 impl Program {
@@ -394,6 +397,6 @@ impl RustIrDatabase<ChalkIr> for Program {
     }
 
     fn is_object_safe(&self, trait_id: TraitId<ChalkIr>) -> bool {
-        self.trait_datum(trait_id).is_object_safe_trait()
+        self.object_safe_traits.contains(&trait_id)
     }
 }

chalk-rust-ir/src/lib.rs

@@ -168,10 +168,6 @@ impl<I: Interner> TraitDatum<I> {
         self.flags.coinductive
     }
 
-    pub fn is_object_safe_trait(&self) -> bool {
-        self.flags.object_safe
-    }
-
     /// Gives access to the where clauses of the trait, quantified over the type parameters of the trait:
     ///
     /// ```ignore
@@ -225,9 +221,6 @@ pub struct TraitFlags {
     pub non_enumerable: bool,
 
     pub coinductive: bool,
-
-    /// Indicates that a trait is object safe
-    pub object_safe: bool,
 }
 
 /// An inline bound, e.g. `: Foo<K>` in `impl<K, T: Foo<K>> SomeType<T>`.