1 files changed, 4 insertions, 4 deletions
diff --git a/compiler/rustc_builtin_macros/src/deriving/clone.rs b/compiler/rustc_builtin_macros/src/deriving/clone.rs
index 267405ac32e..0a44bd42b91 100644
--- a/compiler/rustc_builtin_macros/src/deriving/clone.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/clone.rs
@@ -9,7 +9,7 @@ use rustc_span::Span;
 use thin_vec::{thin_vec, ThinVec};
 
 pub fn expand_deriving_clone(
-    cx: &mut ExtCtxt<'_>,
+    cx: &ExtCtxt<'_>,
     span: Span,
     mitem: &MetaItem,
     item: &Annotatable,
@@ -94,7 +94,7 @@ pub fn expand_deriving_clone(
 
 fn cs_clone_simple(
     name: &str,
-    cx: &mut ExtCtxt<'_>,
+    cx: &ExtCtxt<'_>,
     trait_span: Span,
     substr: &Substructure<'_>,
     is_union: bool,
@@ -157,14 +157,14 @@ fn cs_clone_simple(
 
 fn cs_clone(
     name: &str,
-    cx: &mut ExtCtxt<'_>,
+    cx: &ExtCtxt<'_>,
     trait_span: Span,
     substr: &Substructure<'_>,
 ) -> BlockOrExpr {
     let ctor_path;
     let all_fields;
     let fn_path = cx.std_path(&[sym::clone, sym::Clone, sym::clone]);
-    let subcall = |cx: &mut ExtCtxt<'_>, field: &FieldInfo| {
+    let subcall = |cx: &ExtCtxt<'_>, field: &FieldInfo| {
         let args = thin_vec![field.self_expr.clone()];
         cx.expr_call_global(field.span, fn_path.clone(), args)
     };