Auto merge of #6688 - Manishearth:smarter-root-lint, r=jdm

Handle type parameters in unused_must_root

fixes #6651

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components/script/dom/bindings/js.rs

@@ -81,6 +81,7 @@ impl<T: Reflectable> JS<T> {
 
 /// An unrooted reference to a DOM object for use in layout. `Layout*Helpers`
 /// traits must be implemented on this.
+#[allow_unrooted_interior]
 pub struct LayoutJS<T> {
     ptr: NonZero<*const T>
 }
@@ -270,6 +271,12 @@ impl<T: Reflectable> MutNullableHeap<JS<T>> {
     pub unsafe fn get_inner_as_layout(&self) -> Option<LayoutJS<T>> {
         self.ptr.get().map(|js| js.to_layout())
     }
+
+    /// Get a rooted value out of this object
+    // FIXME(#6684)
+    pub fn get_rooted(&self) -> Option<Root<T>> {
+        self.get().map(|o| o.root())
+    }
 }
 
 impl<T: HeapGCValue+Copy> Default for MutNullableHeap<T> {
@@ -382,6 +389,7 @@ pub unsafe fn trace_roots(tracer: *mut JSTracer) {
 /// are additive, so this object's destruction will not invalidate other roots
 /// for the same JS value. `Root`s cannot outlive the associated
 /// `RootCollection` object.
+#[allow_unrooted_interior]
 pub struct Root<T: Reflectable> {
     /// Reference to rooted value that must not outlive this container
     ptr: NonZero<*const T>,

components/script/dom/bindings/refcounted.rs

@@ -57,6 +57,7 @@ unsafe impl Send for TrustedReference {}
 /// shared among tasks for use in asynchronous operations. The underlying
 /// DOM object is guaranteed to live at least as long as the last outstanding
 /// `Trusted<T>` instance.
+#[allow_unrooted_interior]
 pub struct Trusted<T: Reflectable> {
     /// A pointer to the Rust DOM object of type T, but void to allow
     /// sending `Trusted<T>` between tasks, regardless of T's sendability.

components/script/dom/bindings/trace.rs

@@ -455,6 +455,7 @@ impl<'a, T: JSTraceable> Drop for RootedTraceable<'a, T> {
 #[allow(unrooted_must_root)]
 #[no_move]
 #[derive(JSTraceable)]
+#[allow_unrooted_interior]
 pub struct RootedVec<T: JSTraceable + Reflectable> {
     v: Vec<T>
 }

components/script/dom/bindings/utils.rs

@@ -413,8 +413,7 @@ pub fn reflect_dom_object<T: Reflectable>
 }
 
 /// A struct to store a reference to the reflector of a DOM object.
-// Allowing unused_attribute because the lint sometimes doesn't run in order
-#[allow(raw_pointer_derive, unrooted_must_root, unused_attributes)]
+#[allow(raw_pointer_derive, unrooted_must_root)]
 #[must_root]
 #[servo_lang = "reflector"]
 // If you're renaming or moving this field, update the path in plugins::reflector as well