Introduce jsmanaged_array

components/script/dom/macros.rs

@@ -303,15 +303,6 @@ macro_rules! make_nonzero_dimension_setter(
 /// For use on non-jsmanaged types
 /// Use #[derive(JSTraceable)] on JS managed types
 macro_rules! unsafe_no_jsmanaged_fields(
-    ([$ty:ident; $count:expr]) => (
-        #[allow(unsafe_code)]
-        unsafe impl $crate::dom::bindings::trace::JSTraceable for [$ty; $count] {
-            #[inline]
-            unsafe fn trace(&self, _: *mut ::js::jsapi::JSTracer) {
-                // Do nothing
-            }
-        }
-    );
     ($($ty:ident),+) => (
         $(
             #[allow(unsafe_code)]
@@ -325,6 +316,22 @@ macro_rules! unsafe_no_jsmanaged_fields(
     );
 );
 
+macro_rules! jsmanaged_array(
+    ($count:expr) => (
+        #[allow(unsafe_code)]
+        unsafe impl<T> $crate::dom::bindings::trace::JSTraceable for [T; $count]
+            where T: $crate::dom::bindings::trace::JSTraceable
+        {
+            #[inline]
+            unsafe fn trace(&self, tracer: *mut ::js::jsapi::JSTracer) {
+                for v in self.iter() {
+                    v.trace(tracer);
+                }
+            }
+        }
+    );
+);
+
 /// These are used to generate a event handler which has no special case.
 macro_rules! define_event_handler(
     ($handler: ident, $event_type: ident, $getter: ident, $setter: ident, $setter_fn: ident) => (

components/script/dom/webgltexture.rs

@@ -26,7 +26,7 @@ pub enum TexParameterValue {
 const MAX_LEVEL_COUNT: usize = 31;
 const MAX_FACE_COUNT: usize = 6;
 
-unsafe_no_jsmanaged_fields!([ImageInfo; MAX_LEVEL_COUNT * MAX_FACE_COUNT]);
+jsmanaged_array!(MAX_LEVEL_COUNT * MAX_FACE_COUNT);
 
 #[dom_struct]
 pub struct WebGLTexture {