Add Foreign to SMIR

compiler/rustc_smir/src/rustc_internal/mod.rs

@@ -31,6 +31,10 @@ pub fn adt_def(did: DefId) -> stable_mir::ty::AdtDef {
     with_tables(|t| t.adt_def(did))
 }
 
+pub fn foreign_def(did: DefId) -> stable_mir::ty::ForeignDef {
+    with_tables(|t| t.foreign_def(did))
+}
+
 impl<'tcx> Tables<'tcx> {
     pub fn item_def_id(&self, item: &stable_mir::CrateItem) -> DefId {
         self.def_ids[item.0]
@@ -44,6 +48,10 @@ impl<'tcx> Tables<'tcx> {
         stable_mir::ty::AdtDef(self.create_def_id(did))
     }
 
+    pub fn foreign_def(&mut self, did: DefId) -> stable_mir::ty::ForeignDef {
+        stable_mir::ty::ForeignDef(self.create_def_id(did))
+    }
+
     fn create_def_id(&mut self, did: DefId) -> stable_mir::DefId {
         // FIXME: this becomes inefficient when we have too many ids
         for (i, &d) in self.def_ids.iter().enumerate() {

compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -113,7 +113,9 @@ impl<'tcx> Tables<'tcx> {
                         .collect(),
                 ),
             )),
-            ty::Foreign(_) => todo!(),
+            ty::Foreign(def_id) => {
+                TyKind::RigidTy(RigidTy::Foreign(rustc_internal::foreign_def(*def_id)))
+            }
             ty::Str => TyKind::RigidTy(RigidTy::Str),
             ty::Array(ty, constant) => {
                 TyKind::RigidTy(RigidTy::Array(self.intern_ty(*ty), opaque(constant)))

compiler/rustc_smir/src/stable_mir/ty.rs

@@ -26,6 +26,7 @@ pub enum RigidTy {
     Uint(UintTy),
     Float(FloatTy),
     Adt(AdtDef, AdtSubsts),
+    Foreign(ForeignDef),
     Str,
     Array(Ty, Const),
     Slice(Ty),
@@ -60,6 +61,9 @@ pub enum FloatTy {
     F64,
 }
 
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct ForeignDef(pub(crate) DefId);
+
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct AdtDef(pub(crate) DefId);