3 files changed, 8 insertions, 9 deletions
diff --git a/compiler/rustc_middle/src/mir/interpret/error.rs b/compiler/rustc_middle/src/mir/interpret/error.rs
index c4803448e2b..690fcfe1be4 100644
--- a/compiler/rustc_middle/src/mir/interpret/error.rs
+++ b/compiler/rustc_middle/src/mir/interpret/error.rs
@@ -12,7 +12,8 @@ use rustc_errors::{
 use rustc_macros::HashStable;
 use rustc_session::CtfeBacktrace;
 use rustc_span::def_id::DefId;
-use rustc_target::abi::{call, Align, Size, WrappingRange};
+use rustc_target::abi::{call, Align, Size, VariantIdx, WrappingRange};
+
 use std::borrow::Cow;
 use std::{any::Any, backtrace::Backtrace, fmt};
 
@@ -323,7 +324,9 @@ pub enum UndefinedBehaviorInfo<'a> {
     /// Data size is not equal to target size.
     ScalarSizeMismatch(ScalarSizeMismatch),
     /// A discriminant of an uninhabited enum variant is written.
-    UninhabitedEnumVariantWritten,
+    UninhabitedEnumVariantWritten(VariantIdx),
+    /// An uninhabited enum variant is projected.
+    UninhabitedEnumVariantRead(VariantIdx),
     /// Validation error.
     Validation(ValidationErrorInfo<'a>),
     // FIXME(fee1-dead) these should all be actual variants of the enum instead of dynamically
@@ -393,6 +396,7 @@ pub enum ValidationErrorKind<'tcx> {
     UnsafeCell,
     UninhabitedVal { ty: Ty<'tcx> },
     InvalidEnumTag { value: String },
+    UninhabitedEnumTag,
     UninitEnumTag,
     UninitStr,
     Uninit { expected: ExpectedKind },
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 62805d1e8b5..81e7dc3728a 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -741,9 +741,9 @@ where
 
                 let fields = match this.ty.kind() {
                     ty::Adt(def, _) if def.variants().is_empty() =>
-                        bug!("for_variant called on zero-variant enum"),
+                        bug!("for_variant called on zero-variant enum {}", this.ty),
                     ty::Adt(def, _) => def.variant(variant_index).fields.len(),
-                    _ => bug!(),
+                    _ => bug!("`ty_and_layout_for_variant` on unexpected type {}", this.ty),
                 };
                 tcx.mk_layout(LayoutS {
                     variants: Variants::Single { index: variant_index },
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index f9c1ca9a8b1..3e023ccdead 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -2670,11 +2670,6 @@ impl<'tcx> Ty<'tcx> {
         variant_index: VariantIdx,
     ) -> Option<Discr<'tcx>> {
         match self.kind() {
-            TyKind::Adt(adt, _) if adt.variants().is_empty() => {
-                // 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))
             }