Generate only align(N) when packed aligned

Author: youknowone

src/codegen/mod.rs

@@ -2012,7 +2012,16 @@ impl CodeGenerator for CompInfo {
         if let Some(comment) = item.comment(ctx) {
             attributes.push(attributes::doc(comment));
         }
-        if packed && !is_opaque {
+
+        // We can't specify both packed(N) and align(N), but the align()
+        // should be redundant in this case.
+        let explicit_align = if ctx.options().rust_features().repr_align {
+            explicit_align
+        } else {
+            None
+        };
+
+        if packed && !is_opaque && explicit_align.is_none() {
             let n = layout.map_or(1, |l| l.align);
             assert!(ctx.options().rust_features().repr_packed_n || n == 1);
             let packed_repr = if n == 1 {
@@ -2025,17 +2034,13 @@ impl CodeGenerator for CompInfo {
             attributes.push(attributes::repr("C"));
         }
 
-        if ctx.options().rust_features().repr_align && !packed {
-            // We can't specify both packed(N) and align(N), but the align()
-            // should be redundant in this case.
-            if let Some(explicit) = explicit_align {
-                // Ensure that the struct has the correct alignment even in
-                // presence of alignas.
-                let explicit = helpers::ast_ty::int_expr(explicit as i64);
-                attributes.push(quote! {
-                    #[repr(align(#explicit))]
-                });
-            }
+        if let Some(explicit) = explicit_align {
+            // Ensure that the struct has the correct alignment even in
+            // presence of alignas.
+            let explicit = helpers::ast_ty::int_expr(explicit as i64);
+            attributes.push(quote! {
+                #[repr(align(#explicit))]
+            });
         }
 
         let derivable_traits = derives_of_item(item, ctx, packed);