3 files changed, 4 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index 6f587fdd53c..b601b465668 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -907,6 +907,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
                     NullOp::SizeOf => write!(fmt, "SizeOf({t})"),
                     NullOp::AlignOf => write!(fmt, "AlignOf({t})"),
                     NullOp::OffsetOf(fields) => write!(fmt, "OffsetOf({t}, {fields:?})"),
+                    NullOp::DebugAssertions => write!(fmt, "cfg!(debug_assertions)"),
                 }
             }
             ThreadLocalRef(did) => ty::tls::with(|tcx| {
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
index ca56e1fd92c..40af453f6ce 100644
--- a/compiler/rustc_middle/src/mir/syntax.rs
+++ b/compiler/rustc_middle/src/mir/syntax.rs
@@ -1361,6 +1361,8 @@ pub enum NullOp<'tcx> {
     AlignOf,
     /// Returns the offset of a field
     OffsetOf(&'tcx List<(VariantIdx, FieldIdx)>),
+    /// cfg!(debug_assertions), but expanded in codegen
+    DebugAssertions,
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
diff --git a/compiler/rustc_middle/src/mir/tcx.rs b/compiler/rustc_middle/src/mir/tcx.rs
index 4780042a510..5bc151de659 100644
--- a/compiler/rustc_middle/src/mir/tcx.rs
+++ b/compiler/rustc_middle/src/mir/tcx.rs
@@ -194,6 +194,7 @@ impl<'tcx> Rvalue<'tcx> {
             Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(..), _) => {
                 tcx.types.usize
             }
+            Rvalue::NullaryOp(NullOp::DebugAssertions, _) => tcx.types.bool,
             Rvalue::Aggregate(ref ak, ref ops) => match **ak {
                 AggregateKind::Array(ty) => Ty::new_array(tcx, ty, ops.len() as u64),
                 AggregateKind::Tuple => {