Don't populate rust_ir::AdtVariantDatum::fields for now due to perf

Author: Veykril

crates/hir-ty/src/chalk_db.rs

@@ -742,6 +742,8 @@ pub(crate) fn adt_datum_query(
         phantom_data,
     };
 
+    #[cfg(FALSE)]
+    // this slows down rust-analyzer by quite a bit unfortunately, so enabling this is currently not worth it
     let variant_id_to_fields = |id: VariantId| {
         let variant_data = &id.variant_data(db.upcast());
         let fields = if variant_data.fields().is_empty() {
@@ -757,6 +759,7 @@ pub(crate) fn adt_datum_query(
         };
         rust_ir::AdtVariantDatum { fields }
     };
+    let variant_id_to_fields = |_: VariantId| rust_ir::AdtVariantDatum { fields: vec![] };
 
     let (kind, variants) = match adt_id {
         hir_def::AdtId::StructId(id) => {

crates/hir-ty/src/tests/coercion.rs

@@ -536,15 +536,17 @@ fn test() {
 
 #[test]
 fn coerce_unsize_generic() {
-    check_no_mismatches(
+    check(
         r#"
 //- minicore: coerce_unsized
 struct Foo<T> { t: T };
 struct Bar<T>(Foo<T>);
 
 fn test() {
     let _: &Foo<[usize]> = &Foo { t: [1, 2, 3] };
+                         //^^^^^^^^^^^^^^^^^^^^^ expected &Foo<[usize]>, got &Foo<[i32; 3]>
     let _: &Bar<[usize]> = &Bar(Foo { t: [1, 2, 3] });
+                         //^^^^^^^^^^^^^^^^^^^^^^^^^^ expected &Bar<[usize]>, got &Bar<[i32; 3]>
 }
 "#,
     );

crates/hir-ty/src/tests/traits.rs

@@ -4583,21 +4583,21 @@ fn f<T: Send, U>() {
     Struct::<T>::IS_SEND;
   //^^^^^^^^^^^^^^^^^^^^Yes
     Struct::<U>::IS_SEND;
-  //^^^^^^^^^^^^^^^^^^^^{unknown}
+  //^^^^^^^^^^^^^^^^^^^^Yes
     Struct::<*const T>::IS_SEND;
-  //^^^^^^^^^^^^^^^^^^^^^^^^^^^{unknown}
+  //^^^^^^^^^^^^^^^^^^^^^^^^^^^Yes
     Enum::<T>::IS_SEND;
   //^^^^^^^^^^^^^^^^^^Yes
     Enum::<U>::IS_SEND;
-  //^^^^^^^^^^^^^^^^^^{unknown}
+  //^^^^^^^^^^^^^^^^^^Yes
     Enum::<*const T>::IS_SEND;
-  //^^^^^^^^^^^^^^^^^^^^^^^^^{unknown}
+  //^^^^^^^^^^^^^^^^^^^^^^^^^Yes
     Union::<T>::IS_SEND;
   //^^^^^^^^^^^^^^^^^^^Yes
     Union::<U>::IS_SEND;
-  //^^^^^^^^^^^^^^^^^^^{unknown}
+  //^^^^^^^^^^^^^^^^^^^Yes
     Union::<*const T>::IS_SEND;
-  //^^^^^^^^^^^^^^^^^^^^^^^^^^{unknown}
+  //^^^^^^^^^^^^^^^^^^^^^^^^^^Yes
     PhantomData::<T>::IS_SEND;
   //^^^^^^^^^^^^^^^^^^^^^^^^^Yes
     PhantomData::<U>::IS_SEND;