6 files changed, 60 insertions, 5 deletions
diff --git a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
index 8879e029346..90173da17f0 100644
--- a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
+++ b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
@@ -504,7 +504,8 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
             | Rvalue::Cast(..)
             | Rvalue::BinaryOp(..)
             | Rvalue::Aggregate(..)
-            | Rvalue::ShallowInitBox(..) => {
+            | Rvalue::ShallowInitBox(..)
+            | Rvalue::WrapUnsafeBinder(..) => {
                 // No modification is possible through these r-values.
                 return ValueOrPlace::TOP;
             }
diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs
index 41de1b58b91..7395ad496db 100644
--- a/compiler/rustc_mir_transform/src/dest_prop.rs
+++ b/compiler/rustc_mir_transform/src/dest_prop.rs
@@ -575,6 +575,9 @@ impl WriteInfo {
                             self.add_operand(op);
                         }
                     }
+                    Rvalue::WrapUnsafeBinder(op, _) => {
+                        self.add_operand(op);
+                    }
                     Rvalue::ThreadLocalRef(_)
                     | Rvalue::NullaryOp(_, _)
                     | Rvalue::Ref(_, _, _)
diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs
index 16e15fa12e0..c261e25100d 100644
--- a/compiler/rustc_mir_transform/src/gvn.rs
+++ b/compiler/rustc_mir_transform/src/gvn.rs
@@ -476,6 +476,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                     }
                     ProjectionElem::OpaqueCast(ty) => ProjectionElem::OpaqueCast(ty),
                     ProjectionElem::Subtype(ty) => ProjectionElem::Subtype(ty),
+                    ProjectionElem::UnwrapUnsafeBinder(ty) => {
+                        ProjectionElem::UnwrapUnsafeBinder(ty)
+                    }
                     // This should have been replaced by a `ConstantIndex` earlier.
                     ProjectionElem::Index(_) => return None,
                 };
@@ -713,6 +716,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
             }
             ProjectionElem::OpaqueCast(ty) => ProjectionElem::OpaqueCast(ty),
             ProjectionElem::Subtype(ty) => ProjectionElem::Subtype(ty),
+            ProjectionElem::UnwrapUnsafeBinder(ty) => ProjectionElem::UnwrapUnsafeBinder(ty),
         };
 
         Some(self.insert(Value::Projection(value, proj)))
@@ -867,6 +871,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                 self.simplify_place_projection(place, location);
                 return self.new_pointer(*place, AddressKind::Address(mutbl));
             }
+            Rvalue::WrapUnsafeBinder(ref mut op, _) => {
+                return self.simplify_operand(op, location);
+            }
 
             // Operations.
             Rvalue::Len(ref mut place) => return self.simplify_len(place, location),
@@ -931,6 +938,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
             ProjectionElem::Downcast(symbol, idx) => ProjectionElem::Downcast(symbol, idx),
             ProjectionElem::OpaqueCast(idx) => ProjectionElem::OpaqueCast(idx),
             ProjectionElem::Subtype(idx) => ProjectionElem::Subtype(idx),
+            ProjectionElem::UnwrapUnsafeBinder(ty) => ProjectionElem::UnwrapUnsafeBinder(ty),
         })
     }
 
diff --git a/compiler/rustc_mir_transform/src/known_panics_lint.rs b/compiler/rustc_mir_transform/src/known_panics_lint.rs
index f4ac5c6aa80..2864cc0b9fe 100644
--- a/compiler/rustc_mir_transform/src/known_panics_lint.rs
+++ b/compiler/rustc_mir_transform/src/known_panics_lint.rs
@@ -444,7 +444,8 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             | Rvalue::Cast(..)
             | Rvalue::ShallowInitBox(..)
             | Rvalue::Discriminant(..)
-            | Rvalue::NullaryOp(..) => {}
+            | Rvalue::NullaryOp(..)
+            | Rvalue::WrapUnsafeBinder(..) => {}
         }
 
         // FIXME we need to revisit this for #67176
@@ -546,7 +547,9 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         let val: Value<'_> = match *rvalue {
             ThreadLocalRef(_) => return None,
 
-            Use(ref operand) => self.eval_operand(operand)?.into(),
+            Use(ref operand) | WrapUnsafeBinder(ref operand, _) => {
+                self.eval_operand(operand)?.into()
+            }
 
             CopyForDeref(place) => self.eval_place(place)?.into(),
 
diff --git a/compiler/rustc_mir_transform/src/promote_consts.rs b/compiler/rustc_mir_transform/src/promote_consts.rs
index 6aa3343bb6e..9101c9bfc9a 100644
--- a/compiler/rustc_mir_transform/src/promote_consts.rs
+++ b/compiler/rustc_mir_transform/src/promote_consts.rs
@@ -293,7 +293,8 @@ impl<'tcx> Validator<'_, 'tcx> {
             // Recurse directly.
             ProjectionElem::ConstantIndex { .. }
             | ProjectionElem::Subtype(_)
-            | ProjectionElem::Subslice { .. } => {}
+            | ProjectionElem::Subslice { .. }
+            | ProjectionElem::UnwrapUnsafeBinder(_) => {}
 
             // Never recurse.
             ProjectionElem::OpaqueCast(..) | ProjectionElem::Downcast(..) => {
@@ -426,7 +427,9 @@ impl<'tcx> Validator<'_, 'tcx> {
 
     fn validate_rvalue(&mut self, rvalue: &Rvalue<'tcx>) -> Result<(), Unpromotable> {
         match rvalue {
-            Rvalue::Use(operand) | Rvalue::Repeat(operand, _) => {
+            Rvalue::Use(operand)
+            | Rvalue::Repeat(operand, _)
+            | Rvalue::WrapUnsafeBinder(operand, _) => {
                 self.validate_operand(operand)?;
             }
             Rvalue::CopyForDeref(place) => {
diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs
index 5881264cba5..e282eaf761c 100644
--- a/compiler/rustc_mir_transform/src/validate.rs
+++ b/compiler/rustc_mir_transform/src/validate.rs
@@ -807,6 +807,25 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     )
                 }
             }
+            ProjectionElem::UnwrapUnsafeBinder(unwrapped_ty) => {
+                let binder_ty = place_ref.ty(&self.body.local_decls, self.tcx);
+                let ty::UnsafeBinder(binder_ty) = *binder_ty.ty.kind() else {
+                    self.fail(
+                        location,
+                        format!("WrapUnsafeBinder does not produce a ty::UnsafeBinder"),
+                    );
+                    return;
+                };
+                let binder_inner_ty = self.tcx.instantiate_bound_regions_with_erased(*binder_ty);
+                if !self.mir_assign_valid_types(unwrapped_ty, binder_inner_ty) {
+                    self.fail(
+                        location,
+                        format!(
+                            "Cannot unwrap unsafe binder {binder_ty:?} into type {unwrapped_ty:?}"
+                        ),
+                    );
+                }
+            }
             _ => {}
         }
         self.super_projection_elem(place_ref, elem, context, location);
@@ -1362,6 +1381,24 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             | Rvalue::RawPtr(_, _)
             | Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::UbChecks, _)
             | Rvalue::Discriminant(_) => {}
+
+            Rvalue::WrapUnsafeBinder(op, ty) => {
+                let unwrapped_ty = op.ty(self.body, self.tcx);
+                let ty::UnsafeBinder(binder_ty) = *ty.kind() else {
+                    self.fail(
+                        location,
+                        format!("WrapUnsafeBinder does not produce a ty::UnsafeBinder"),
+                    );
+                    return;
+                };
+                let binder_inner_ty = self.tcx.instantiate_bound_regions_with_erased(*binder_ty);
+                if !self.mir_assign_valid_types(unwrapped_ty, binder_inner_ty) {
+                    self.fail(
+                        location,
+                        format!("Cannot wrap {unwrapped_ty:?} into unsafe binder {binder_ty:?}"),
+                    );
+                }
+            }
         }
         self.super_rvalue(rvalue, location);
     }