Replace NonZero<*mut JSObject> with a wrapper to enable local trait impls.

components/script/dom/bindings/codegen/CodegenRust.py

@@ -1407,7 +1407,7 @@ def getRetvalDeclarationForType(returnType, descriptorProvider):
     if returnType.isAny():
         return CGGeneric("JSVal")
     if returnType.isObject() or returnType.isSpiderMonkeyInterface():
-        result = CGGeneric("NonZero<*mut JSObject>")
+        result = CGGeneric("NonNullJSObjectPtr")
         if returnType.nullable():
             result = CGWrapper(result, pre="Option<", post=">")
         return result
@@ -2253,6 +2253,7 @@ def UnionTypes(descriptors, dictionaries, callbacks, typedefs, config):
         'dom::bindings::conversions::StringificationBehavior',
         'dom::bindings::conversions::root_from_handlevalue',
         'dom::bindings::error::throw_not_in_union',
+        'dom::bindings::nonnull::NonNullJSObjectPtr',
         'dom::bindings::mozmap::MozMap',
         'dom::bindings::root::DomRoot',
         'dom::bindings::str::ByteString',
@@ -5785,6 +5786,7 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
         'dom::bindings::proxyhandler::get_expando_object',
         'dom::bindings::proxyhandler::get_property_descriptor',
         'dom::bindings::mozmap::MozMap',
+        'dom::bindings::nonnull::NonNullJSObjectPtr',
         'dom::bindings::num::Finite',
         'dom::bindings::str::ByteString',
         'dom::bindings::str::DOMString',

components/script/dom/bindings/conversions.rs

@@ -34,6 +34,7 @@
 
 use dom::bindings::error::{Error, Fallible};
 use dom::bindings::inheritance::Castable;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{DomObject, Reflector};
 use dom::bindings::root::DomRoot;
@@ -53,7 +54,7 @@ use js::jsapi::{JS_GetLatin1StringCharsAndLength, JS_GetProperty, JS_GetReserved
 use js::jsapi::{JS_GetTwoByteStringCharsAndLength, JS_IsArrayObject, JS_IsExceptionPending};
 use js::jsapi::{JS_NewStringCopyN, JS_StringHasLatin1Chars, MutableHandleValue};
 use js::jsval::{ObjectValue, StringValue, UndefinedValue};
-use js::rust::{ToString, get_object_class, is_dom_class, is_dom_object, maybe_wrap_value};
+use js::rust::{ToString, get_object_class, is_dom_class, is_dom_object, maybe_wrap_value, maybe_wrap_object_value};
 use libc;
 use num_traits::Float;
 use servo_config::opts;
@@ -69,6 +70,15 @@ pub trait IDLInterface {
 #[rustc_on_unimplemented = "The IDL interface `{Self}` is not derived from `{T}`."]
 pub trait DerivedFrom<T: Castable>: Castable {}
 
+// https://heycam.github.io/webidl/#es-object
+impl ToJSValConvertible for NonNullJSObjectPtr {
+    #[inline]
+    unsafe fn to_jsval(&self, cx: *mut JSContext, rval: MutableHandleValue) {
+        rval.set(ObjectValue(self.get()));
+        maybe_wrap_object_value(cx, rval);
+    }
+}
+
 impl<T: Float + ToJSValConvertible> ToJSValConvertible for Finite<T> {
     #[inline]
     unsafe fn to_jsval(&self, cx: *mut JSContext, rval: MutableHandleValue) {

components/script/dom/bindings/iterable.rs

@@ -6,17 +6,17 @@
 
 //! Implementation of `iterable<...>` and `iterable<..., ...>` WebIDL declarations.
 
-use core::nonzero::NonZero;
 use dom::bindings::codegen::Bindings::IterableIteratorBinding::IterableKeyAndValueResult;
 use dom::bindings::codegen::Bindings::IterableIteratorBinding::IterableKeyOrValueResult;
 use dom::bindings::error::Fallible;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
 use dom::bindings::trace::JSTraceable;
 use dom::globalscope::GlobalScope;
 use dom_struct::dom_struct;
 use js::conversions::ToJSValConvertible;
-use js::jsapi::{HandleValue, Heap, JSContext, JSObject, MutableHandleObject};
+use js::jsapi::{HandleValue, Heap, JSContext, MutableHandleObject};
 use js::jsval::UndefinedValue;
 use std::cell::Cell;
 use std::ptr;
@@ -73,7 +73,7 @@ impl<T: DomObject + JSTraceable + Iterable> IterableIterator<T> {
 
     /// Return the next value from the iterable object.
     #[allow(non_snake_case)]
-    pub fn Next(&self, cx: *mut JSContext) -> Fallible<NonZero<*mut JSObject>> {
+    pub fn Next(&self, cx: *mut JSContext) -> Fallible<NonNullJSObjectPtr> {
         let index = self.index.get();
         rooted!(in(cx) let mut value = UndefinedValue());
         rooted!(in(cx) let mut rval = ptr::null_mut());
@@ -106,7 +106,7 @@ impl<T: DomObject + JSTraceable + Iterable> IterableIterator<T> {
         self.index.set(index + 1);
         result.map(|_| {
             assert!(!rval.is_null());
-            unsafe { NonZero::new_unchecked(rval.get()) }
+            unsafe { NonNullJSObjectPtr::new_unchecked(rval.get()) }
         })
     }
 }

components/script/dom/bindings/mod.rs

@@ -144,6 +144,7 @@ pub mod interface;
 pub mod iterable;
 pub mod mozmap;
 pub mod namespace;
+pub mod nonnull;
 pub mod num;
 pub mod proxyhandler;
 pub mod refcounted;

components/script/dom/bindings/nonnull.rs

@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! A wrapper type for `NonZero<*mut JSObject>`, to enable local trait impls
+
+use js::jsapi::JSObject;
+use nonzero::NonZero;
+
+/// A wrapper type for `NonZero<*mut JSObject>`, to enable local trait impls
+#[derive(Clone, Copy)]
+pub struct NonNullJSObjectPtr(NonZero<*mut JSObject>);
+
+impl NonNullJSObjectPtr {
+    #[inline]
+    pub unsafe fn new_unchecked(ptr: *mut JSObject) -> Self {
+        NonNullJSObjectPtr(NonZero::new_unchecked(ptr))
+    }
+
+    #[inline]
+    pub fn get(self) -> *mut JSObject {
+        self.0.get()
+    }
+}