1 files changed, 23 insertions, 17 deletions
diff --git a/compiler/rustc_mir_transform/src/check_packed_ref.rs b/compiler/rustc_mir_transform/src/check_packed_ref.rs
index 3b7ba3f9a..51abcf511 100644
--- a/compiler/rustc_mir_transform/src/check_packed_ref.rs
+++ b/compiler/rustc_mir_transform/src/check_packed_ref.rs
@@ -33,21 +33,27 @@ struct PackedRefChecker<'a, 'tcx> {
 fn unsafe_derive_on_repr_packed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     let lint_hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
 
-    tcx.struct_span_lint_hir(UNALIGNED_REFERENCES, lint_hir_id, tcx.def_span(def_id), |lint| {
-        // FIXME: when we make this a hard error, this should have its
-        // own error code.
-        let extra = if tcx.generics_of(def_id).own_requires_monomorphization() {
-            "with type or const parameters"
-        } else {
-            "that does not derive `Copy`"
-        };
-        let message = format!(
-            "`{}` can't be derived on this `#[repr(packed)]` struct {}",
-            tcx.item_name(tcx.trait_id_of_impl(def_id.to_def_id()).expect("derived trait name")),
-            extra
-        );
-        lint.build(message).emit();
-    });
+    // FIXME: when we make this a hard error, this should have its
+    // own error code.
+
+    let extra = if tcx.generics_of(def_id).own_requires_monomorphization() {
+        "with type or const parameters"
+    } else {
+        "that does not derive `Copy`"
+    };
+    let message = format!(
+        "`{}` can't be derived on this `#[repr(packed)]` struct {}",
+        tcx.item_name(tcx.trait_id_of_impl(def_id.to_def_id()).expect("derived trait name")),
+        extra
+    );
+
+    tcx.struct_span_lint_hir(
+        UNALIGNED_REFERENCES,
+        lint_hir_id,
+        tcx.def_span(def_id),
+        message,
+        |lint| lint,
+    );
 }
 
 impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
@@ -86,8 +92,9 @@ impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
                         UNALIGNED_REFERENCES,
                         lint_root,
                         source_info.span,
+                        "reference to packed field is unaligned",
                         |lint| {
-                            lint.build("reference to packed field is unaligned")
+                            lint
                                 .note(
                                     "fields of packed structs are not properly aligned, and creating \
                                     a misaligned reference is undefined behavior (even if that \
@@ -98,7 +105,6 @@ impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
                                     reference with a raw pointer and use `read_unaligned`/`write_unaligned` \
                                     (loads and stores via `*p` must be properly aligned even when using raw pointers)"
                                 )
-                                .emit();
                         },
                     );
                 }