fix getting the discriminant of a zero-variant enum

2021-11-14 13:28:47 -05:00
parent c8e94975a6
commit eebf676bf8
2 changed files with 9 additions and 1 deletions
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -2067,7 +2067,9 @@ impl<'tcx> TyS<'tcx> {
    ) -> Option<Discr<'tcx>> {
        match self.kind() {
            TyKind::Adt(adt, _) if adt.variants.is_empty() => {
-                bug!("discriminant_for_variant called on zero variant enum");
+                // This can actually happen during CTFE, see
+                // https://github.com/rust-lang/rust/issues/89765.
+                None
            }
            TyKind::Adt(adt, _) if adt.is_enum() => {
                Some(adt.discriminant_for_variant(tcx, variant_index))