Use Chalk's built-in representation of function item types

4 files changed, 75 insertions, 10 deletions

diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index e2f2a9ccb..5b0f12a3c 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -14,7 +14,7 @@ use ra_db::{salsa::InternKey, CrateId};
 use super::{builtin, AssocTyValue, ChalkContext, Impl};
 use crate::{
     db::HirDatabase, display::HirDisplay, method_resolution::TyFingerprint, utils::generics,
-    DebruijnIndex, GenericPredicate, Substs, Ty, TypeCtor,
+    CallableDef, DebruijnIndex, GenericPredicate, Substs, Ty, TypeCtor,
 };
 use chalk_rust_ir::WellKnownTrait;
 use mapping::{convert_where_clauses, generic_predicate_to_inline_bound, make_binders};
@@ -54,10 +54,9 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
 
     fn fn_def_datum(
         &self,
-        _fn_def_id: chalk_ir::FnDefId<Interner>,
+        fn_def_id: chalk_ir::FnDefId<Interner>,
     ) -> Arc<chalk_rust_ir::FnDefDatum<Interner>> {
-        // We don't yet provide any FnDefs to Chalk
-        unimplemented!()
+        self.db.fn_def_datum(self.krate, fn_def_id)
     }
 
     fn impls_for_trait(
@@ -405,6 +404,26 @@ fn type_alias_associated_ty_value(
     Arc::new(value)
 }
 
+pub(crate) fn fn_def_datum_query(
+    db: &dyn HirDatabase,
+    _krate: CrateId,
+    fn_def_id: FnDefId,
+) -> Arc<FnDefDatum> {
+    let callable_def: CallableDef = from_chalk(db, fn_def_id);
+    let generic_params = generics(db.upcast(), callable_def.into());
+    let sig = db.callable_item_signature(callable_def);
+    let bound_vars = Substs::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
+    let where_clauses = convert_where_clauses(db, callable_def.into(), &bound_vars);
+    let bound = chalk_rust_ir::FnDefDatumBound {
+        // Note: Chalk doesn't actually use this information yet as far as I am aware, but we provide it anyway
+        argument_types: sig.value.params().iter().map(|ty| ty.clone().to_chalk(db)).collect(),
+        return_type: sig.value.ret().clone().to_chalk(db),
+        where_clauses,
+    };
+    let datum = FnDefDatum { id: fn_def_id, binders: make_binders(bound, sig.num_binders) };
+    Arc::new(datum)
+}
+
 impl From<AdtId> for crate::TypeCtorId {
     fn from(struct_id: AdtId) -> Self {
         struct_id.0
@@ -417,6 +436,18 @@ impl From<crate::TypeCtorId> for AdtId {
     }
 }
 
+impl From<FnDefId> for crate::CallableDefId {
+    fn from(fn_def_id: FnDefId) -> Self {
+        InternKey::from_intern_id(fn_def_id.0)
+    }
+}
+
+impl From<crate::CallableDefId> for FnDefId {
+    fn from(callable_def_id: crate::CallableDefId) -> Self {
+        chalk_ir::FnDefId(callable_def_id.as_intern_id())
+    }
+}
+
 impl From<ImplId> for crate::traits::GlobalImplId {
     fn from(impl_id: ImplId) -> Self {
         InternKey::from_intern_id(impl_id.0)
diff --git a/crates/ra_hir_ty/src/traits/chalk/interner.rs b/crates/ra_hir_ty/src/traits/chalk/interner.rs
index 060372819..2a27f8ed8 100644
--- a/crates/ra_hir_ty/src/traits/chalk/interner.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/interner.rs
@@ -20,6 +20,8 @@ pub type ImplId = chalk_ir::ImplId<Interner>;
 pub type ImplDatum = chalk_rust_ir::ImplDatum<Interner>;
 pub type AssociatedTyValueId = chalk_rust_ir::AssociatedTyValueId<Interner>;
 pub type AssociatedTyValue = chalk_rust_ir::AssociatedTyValue<Interner>;
+pub type FnDefId = chalk_ir::FnDefId<Interner>;
+pub type FnDefDatum = chalk_rust_ir::FnDefDatum<Interner>;
 
 impl chalk_ir::interner::Interner for Interner {
     type InternedType = Box<chalk_ir::TyData<Self>>; // FIXME use Arc?
diff --git a/crates/ra_hir_ty/src/traits/chalk/mapping.rs b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
index a83d82fd8..7841a0e21 100644
--- a/crates/ra_hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
@@ -15,8 +15,8 @@ use crate::{
     db::HirDatabase,
     primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness, Uncertain},
     traits::{builtin, AssocTyValue, Canonical, Impl, Obligation},
-    ApplicationTy, GenericPredicate, InEnvironment, ProjectionPredicate, ProjectionTy, Substs,
-    TraitEnvironment, TraitRef, Ty, TypeCtor,
+    ApplicationTy, CallableDef, GenericPredicate, InEnvironment, ProjectionPredicate, ProjectionTy,
+    Substs, TraitEnvironment, TraitRef, Ty, TypeCtor,
 };
 
 use super::interner::*;
@@ -217,11 +217,14 @@ impl ToChalk for TypeCtor {
             TypeCtor::Slice => TypeName::Slice,
             TypeCtor::Ref(mutability) => TypeName::Ref(mutability.to_chalk(db)),
             TypeCtor::Str => TypeName::Str,
+            TypeCtor::FnDef(callable_def) => {
+                let id = callable_def.to_chalk(db);
+                TypeName::FnDef(id)
+            }
             TypeCtor::Int(Uncertain::Unknown)
             | TypeCtor::Float(Uncertain::Unknown)
             | TypeCtor::Adt(_)
             | TypeCtor::Array
-            | TypeCtor::FnDef(_)
             | TypeCtor::FnPtr { .. }
             | TypeCtor::Never
             | TypeCtor::Closure { .. } => {
@@ -260,7 +263,10 @@ impl ToChalk for TypeCtor {
             TypeName::Ref(mutability) => TypeCtor::Ref(from_chalk(db, mutability)),
             TypeName::Str => TypeCtor::Str,
 
-            TypeName::FnDef(_) => unreachable!(),
+            TypeName::FnDef(fn_def_id) => {
+                let callable_def = from_chalk(db, fn_def_id);
+                TypeCtor::FnDef(callable_def)
+            }
 
             TypeName::Error => {
                 // this should not be reached, since we don't represent TypeName::Error with TypeCtor
@@ -347,6 +353,18 @@ impl ToChalk for Impl {
     }
 }
 
+impl ToChalk for CallableDef {
+    type Chalk = FnDefId;
+
+    fn to_chalk(self, db: &dyn HirDatabase) -> FnDefId {
+        db.intern_callable_def(self).into()
+    }
+
+    fn from_chalk(db: &dyn HirDatabase, fn_def_id: FnDefId) -> CallableDef {
+        db.lookup_intern_callable_def(fn_def_id.into())
+    }
+}
+
 impl ToChalk for TypeAliasId {
     type Chalk = AssocTypeId;
 
diff --git a/crates/ra_hir_ty/src/traits/chalk/tls.rs b/crates/ra_hir_ty/src/traits/chalk/tls.rs
index ebf402a07..d88828c7c 100644
--- a/crates/ra_hir_ty/src/traits/chalk/tls.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/tls.rs
@@ -247,10 +247,24 @@ impl DebugContext<'_> {
 
     pub fn debug_fn_def_id(
         &self,
-        _fn_def_id: chalk_ir::FnDefId<Interner>,
+        fn_def_id: chalk_ir::FnDefId<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> Result<(), fmt::Error> {
-        write!(fmt, "fn")
+        let def: CallableDef = from_chalk(self.0, fn_def_id);
+        let name = match def {
+            CallableDef::FunctionId(ff) => self.0.function_data(ff).name.clone(),
+            CallableDef::StructId(s) => self.0.struct_data(s).name.clone(),
+            CallableDef::EnumVariantId(e) => {
+                let enum_data = self.0.enum_data(e.parent);
+                enum_data.variants[e.local_id].name.clone()
+            }
+        };
+        match def {
+            CallableDef::FunctionId(_) => write!(fmt, "{{fn {}}}", name),
+            CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {
+                write!(fmt, "{{ctor {}}}", name)
+            }
+        }
     }
 
     pub fn debug_const(