servo: Merge #19829 - Update Rust and use the newly-stable std::ptr::NonNull (from servo:rustup); r=nox

Source-Repo: https://github.com/servo/servo Source-Revision: c1ed4bb2d5ed6a4f9967215620d2105cda5ef76a --HG-- extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear extra : subtree_revision : 4f69ae87c412562cfab10b101d17dceab6c387ee
2018-01-22 11:11:44 -06:00 · 2018-01-22 11:11:44 -06:00 · 7b81925deb
--- a/servo/Cargo.lock
+++ b/servo/Cargo.lock
@ -1455,7 +1455,6 @@ dependencies = [
 "metrics 0.0.1",
 "msg 0.0.1",
 "net_traits 0.0.1",
- "nonzero 0.0.1",
 "parking_lot 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "profile_traits 0.0.1",
 "range 0.0.1",
@ -1617,7 +1616,7 @@ dependencies = [
 "cssparser 0.23.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "euclid 0.16.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "hashglobe 0.1.0",
- "mozjs 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mozjs 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
 "selectors 0.19.0",
 "servo_arc 0.1.0",
 "smallbitvec 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
@ -1778,7 +1777,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"

 [[package]]
 name = "mozjs"
-version = "0.1.10"
+version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "cmake 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)",
@ -2434,10 +2433,9 @@ dependencies = [
 "mime 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "mime_guess 1.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "mitochondria 1.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "mozjs 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mozjs 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
 "msg 0.0.1",
 "net_traits 0.0.1",
- "nonzero 0.0.1",
 "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
 "offscreen_gl_context 0.14.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "open 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@ -2496,7 +2494,6 @@ dependencies = [
 "metrics 0.0.1",
 "msg 0.0.1",
 "net_traits 0.0.1",
- "nonzero 0.0.1",
 "profile_traits 0.0.1",
 "range 0.0.1",
 "script_traits 0.0.1",
@ -3704,7 +3701,7 @@ dependencies = [
 "checksum mio 0.6.9 (registry+https://github.com/rust-lang/crates.io-index)" = "9e965267d4d58496fc4f740e9861118367f13570cadf66316ed2c3f2f14d87c7"
 "checksum miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
 "checksum mitochondria 1.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9de3eca27871df31c33b807f834b94ef7d000956f57aa25c5aed9c5f0aae8f6f"
-"checksum mozjs 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "2cd8370617e9a151ed9e7b49f38092075d0ae80bdf9f1dcd807a60cc9c3b7151"
+"checksum mozjs 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "199f707066bf05b559ef6e46741c20e4f7bca8ae3a9c9d953d728dbb840f4eaa"
 "checksum mozjs_sys 0.50.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ef1e24df9f76502cd4459919098ec1ac3af75ce694ec5b8837aa91f69f2ad0eb"
 "checksum mp3-metadata 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4ab5f1d2693586420208d1200ce5a51cd44726f055b635176188137aff42c7de"
 "checksum mp4parse 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f821e3799bc0fd16d9b861fb02fa7ee1b5fba29f45ad591dade105c48ca9a1a0"
--- a/servo/components/hashglobe/src/shim.rs
+++ b/servo/components/hashglobe/src/shim.rs
@ -1,5 +1,6 @@
 use std::marker::PhantomData;

+// FIXME: remove this and use std::ptr::NonNull when Firefox requires Rust 1.25+
 pub struct NonZeroPtr<T: 'static>(&'static T);

 impl<T: 'static> NonZeroPtr<T> {
@ -57,4 +58,4 @@ impl<'a, T> From<&'a mut T> for Shared<T> {
    fn from(reference: &'a mut T) -> Self {
        unsafe { Shared::new_unchecked(reference) }
    }
-}
+}
--- a/servo/components/layout/model.rs
+++ b/servo/components/layout/model.rs
@ -548,7 +548,7 @@ impl SizeConstraint {
        max_size = max_size.map(|x| max(x, min_size));

        if let Some(border) = border {
-            min_size = max((min_size - border), Au(0));
+            min_size = max(min_size - border, Au(0));
            max_size = max_size.map(|x| max(x - border, Au(0)));
        }

--- a/servo/components/layout/query.rs
+++ b/servo/components/layout/query.rs
@ -868,7 +868,7 @@ pub fn process_node_overflow_request<N: LayoutNode>(requested_node: N) -> NodeOv
    let style = &*layout_node.as_element().unwrap().resolved_style();
    let style_box = style.get_box();

-    NodeOverflowResponse(Some((Point2D::new(style_box.overflow_x, style_box.overflow_y))))
+    NodeOverflowResponse(Some(Point2D::new(style_box.overflow_x, style_box.overflow_y)))
 }

 pub fn process_margin_style_query<N: LayoutNode>(requested_node: N)
--- a/servo/components/layout/wrapper.rs
+++ b/servo/components/layout/wrapper.rs
@ -67,7 +67,7 @@ pub trait GetRawData {
 impl<T: GetLayoutData> GetRawData for T {
    fn get_raw_data(&self) -> Option<&StyleAndLayoutData> {
        self.get_style_and_layout_data().map(|opaque| {
-            let container = opaque.ptr.get() as *mut StyleAndLayoutData;
+            let container = opaque.ptr.as_ptr() as *mut StyleAndLayoutData;
            unsafe { &*container }
        })
    }
--- a/servo/components/layout_thread/Cargo.toml
+++ b/servo/components/layout_thread/Cargo.toml
@ -10,7 +10,7 @@ name = "layout_thread"
 path = "lib.rs"

 [features]
-unstable = ["parking_lot/nightly", "nonzero/unstable"]
+unstable = ["parking_lot/nightly"]

 [dependencies]
 app_units = "0.6"
@ -30,7 +30,6 @@ malloc_size_of = { path = "../malloc_size_of" }
 metrics = {path = "../metrics"}
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
-nonzero = {path = "../nonzero"}
 parking_lot = "0.4"
 profile_traits = {path = "../profile_traits"}
 range = {path = "../range"}
--- a/servo/components/layout_thread/dom_wrapper.rs
+++ b/servo/components/layout_thread/dom_wrapper.rs
@ -36,7 +36,6 @@ use html5ever::{LocalName, Namespace};
 use layout::data::StyleAndLayoutData;
 use layout::wrapper::GetRawData;
 use msg::constellation_msg::{BrowsingContextId, PipelineId};
-use nonzero::NonZero;
 use range::Range;
 use script::layout_exports::{CharacterDataTypeId, ElementTypeId, HTMLElementTypeId, NodeTypeId};
 use script::layout_exports::{Document, Element, Node, Text};
@ -59,6 +58,7 @@ use std::fmt;
 use std::fmt::Debug;
 use std::hash::{Hash, Hasher};
 use std::marker::PhantomData;
+use std::ptr::NonNull;
 use std::sync::atomic::Ordering;
 use style::CaseSensitivityExt;
 use style::applicable_declarations::ApplicableDeclarationBlock;
@ -76,7 +76,7 @@ use style::shared_lock::{SharedRwLock as StyleSharedRwLock, Locked as StyleLocke
 use style::str::is_whitespace;

 pub unsafe fn drop_style_and_layout_data(data: OpaqueStyleAndLayoutData) {
-    let ptr = data.ptr.get() as *mut StyleData;
+    let ptr = data.ptr.as_ptr() as *mut StyleData;
    let non_opaque: *mut StyleAndLayoutData = ptr as *mut _;
    let _ = Box::from_raw(non_opaque);
 }
@ -229,7 +229,7 @@ impl<'ln> LayoutNode for ServoLayoutNode<'ln> {
            let ptr: *mut StyleAndLayoutData =
                Box::into_raw(Box::new(StyleAndLayoutData::new()));
            let opaque = OpaqueStyleAndLayoutData {
-                ptr: NonZero::new_unchecked(ptr as *mut StyleData),
+                ptr: NonNull::new_unchecked(ptr as *mut StyleData),
            };
            self.init_style_and_layout_data(opaque);
        };
@ -450,7 +450,7 @@ impl<'le> TElement for ServoLayoutElement<'le> {
    fn get_data(&self) -> Option<&AtomicRefCell<ElementData>> {
        unsafe {
            self.get_style_and_layout_data().map(|d| {
-                &(*(d.ptr.get() as *mut StyleData)).element_data
+                &(*(d.ptr.as_ptr() as *mut StyleData)).element_data
            })
        }
    }
@ -575,7 +575,7 @@ impl<'le> ServoLayoutElement<'le> {

    fn get_style_data(&self) -> Option<&StyleData> {
        unsafe {
-            self.get_style_and_layout_data().map(|d| &*(d.ptr.get() as *mut StyleData))
+            self.get_style_and_layout_data().map(|d| &*(d.ptr.as_ptr() as *mut StyleData))
        }
    }

--- a/servo/components/layout_thread/lib.rs
+++ b/servo/components/layout_thread/lib.rs
@ -28,7 +28,6 @@ extern crate malloc_size_of;
 extern crate metrics;
 extern crate msg;
 extern crate net_traits;
-extern crate nonzero;
 extern crate parking_lot;
 #[macro_use]
 extern crate profile_traits;
--- a/servo/components/script/Cargo.toml
+++ b/servo/components/script/Cargo.toml
@ -65,7 +65,6 @@ mime_guess = "1.8.0"
 mozjs = { version = "0.1.10", features = ["promises"]}
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
-nonzero = {path = "../nonzero"}
 num-traits = "0.1.32"
 offscreen_gl_context = { version = "0.14", features = ["serde"] }
 open = "1.1.1"
--- a/servo/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/servo/components/script/dom/bindings/codegen/CodegenRust.py
@ -1422,7 +1422,7 @@ def getRetvalDeclarationForType(returnType, descriptorProvider):
    if returnType.isAny():
        return CGGeneric("JSVal")
    if returnType.isObject() or returnType.isSpiderMonkeyInterface():
-        result = CGGeneric("NonNullJSObjectPtr")
+        result = CGGeneric("NonNull<JSObject>")
        if returnType.nullable():
            result = CGWrapper(result, pre="Option<", post=">")
        return result
@ -2268,7 +2268,7 @@ 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',
+        'std::ptr::NonNull',
        'dom::bindings::mozmap::MozMap',
        'dom::bindings::root::DomRoot',
        'dom::bindings::str::ByteString',
@ -5811,7 +5811,7 @@ 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',
+        'std::ptr::NonNull',
        'dom::bindings::num::Finite',
        'dom::bindings::str::ByteString',
        'dom::bindings::str::DOMString',
--- a/servo/components/script/dom/bindings/conversions.rs
+++ b/servo/components/script/dom/bindings/conversions.rs
@ -34,7 +34,6 @@

 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;
@ -54,7 +53,7 @@ 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, maybe_wrap_object_value};
+use js::rust::{ToString, get_object_class, is_dom_class, is_dom_object, maybe_wrap_value};
 use libc;
 use num_traits::Float;
 use servo_config::opts;
@ -71,15 +70,6 @@ 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) {
--- a/servo/components/script/dom/bindings/iterable.rs
+++ b/servo/components/script/dom/bindings/iterable.rs
@ -9,7 +9,6 @@
 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;
@ -20,6 +19,7 @@ use js::jsapi::{HandleValue, Heap, JSContext, MutableHandleObject, JSObject};
 use js::jsval::UndefinedValue;
 use std::cell::Cell;
 use std::ptr;
+use std::ptr::NonNull;

 /// The values that an iterator will iterate over.
 #[derive(JSTraceable, MallocSizeOf)]
@ -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<NonNullJSObjectPtr> {
+    pub fn Next(&self, cx: *mut JSContext) -> Fallible<NonNull<JSObject>> {
        let index = self.index.get();
        rooted!(in(cx) let mut value = UndefinedValue());
        rooted!(in(cx) let mut rval = ptr::null_mut::<JSObject>());
@ -105,8 +105,7 @@ impl<T: DomObject + JSTraceable + Iterable> IterableIterator<T> {
        };
        self.index.set(index + 1);
        result.map(|_| {
-            assert!(!rval.is_null());
-            unsafe { NonNullJSObjectPtr::new_unchecked(rval.get()) }
+            NonNull::new(rval.get()).expect("got a null pointer")
        })
    }
 }
--- a/servo/components/script/dom/bindings/mod.rs
+++ b/servo/components/script/dom/bindings/mod.rs
@ -145,7 +145,6 @@ pub mod interface;
 pub mod iterable;
 pub mod mozmap;
 pub mod namespace;
-pub mod nonnull;
 pub mod num;
 pub mod proxyhandler;
 pub mod refcounted;
--- a/servo/components/script/dom/bindings/nonnull.rs
+++ b/servo/components/script/dom/bindings/nonnull.rs
@ -1,24 +0,0 @@
-/* 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()
-    }
-}
--- a/servo/components/script/dom/bindings/root.rs
+++ b/servo/components/script/dom/bindings/root.rs
@ -34,7 +34,6 @@ use js::jsapi::{JSObject, JSTracer, Heap};
 use js::rust::GCMethods;
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
 use mitochondria::OnceCell;
-use nonzero::NonZero;
 use script_layout_interface::TrustedNodeAddress;
 use std::cell::{Cell, UnsafeCell};
 use std::default::Default;
@ -312,7 +311,7 @@ impl<'root, T: RootedReference<'root> + 'root> RootedReference<'root> for Option
 /// This should only be used as a field in other DOM objects.
 #[must_root]
 pub struct Dom<T> {
-    ptr: NonZero<*const T>,
+    ptr: ptr::NonNull<T>,
 }

 // Dom<T> is similar to Rc<T>, in that it's not always clear how to avoid double-counting.
@ -339,7 +338,7 @@ impl<T: DomObject> Dom<T> {
    pub fn from_ref(obj: &T) -> Dom<T> {
        debug_assert!(thread_state::get().is_script());
        Dom {
-            ptr: unsafe { NonZero::new_unchecked(&*obj) },
+            ptr: ptr::NonNull::from(obj),
        }
    }
 }
@ -351,7 +350,7 @@ impl<T: DomObject> Deref for Dom<T> {
        debug_assert!(thread_state::get().is_script());
        // We can only have &Dom<T> from a rooted thing, so it's safe to deref
        // it to &T.
-        unsafe { &*self.ptr.get() }
+        unsafe { &*self.ptr.as_ptr() }
    }
 }

@ -366,7 +365,7 @@ unsafe impl<T: DomObject> JSTraceable for Dom<T> {

        trace_reflector(trc,
                        trace_info,
-                        (*self.ptr.get()).reflector());
+                        (*self.ptr.as_ptr()).reflector());
    }
 }

@ -374,7 +373,7 @@ unsafe impl<T: DomObject> JSTraceable for Dom<T> {
 /// traits must be implemented on this.
 #[allow_unrooted_interior]
 pub struct LayoutDom<T> {
-    ptr: NonZero<*const T>,
+    ptr: ptr::NonNull<T>,
 }

 impl<T: Castable> LayoutDom<T> {
@ -384,9 +383,9 @@ impl<T: Castable> LayoutDom<T> {
              T: DerivedFrom<U>
    {
        debug_assert!(thread_state::get().is_layout());
-        let ptr: *const T = self.ptr.get();
+        let ptr: *mut T = self.ptr.as_ptr();
        LayoutDom {
-            ptr: unsafe { NonZero::new_unchecked(ptr as *const U) },
+            ptr: unsafe { ptr::NonNull::new_unchecked(ptr as *mut U) },
        }
    }

@ -397,9 +396,9 @@ impl<T: Castable> LayoutDom<T> {
        debug_assert!(thread_state::get().is_layout());
        unsafe {
            if (*self.unsafe_get()).is::<U>() {
-                let ptr: *const T = self.ptr.get();
+                let ptr: *mut T = self.ptr.as_ptr();
                Some(LayoutDom {
-                    ptr: NonZero::new_unchecked(ptr as *const U),
+                    ptr: ptr::NonNull::new_unchecked(ptr as *mut U),
                })
            } else {
                None
@ -412,7 +411,7 @@ impl<T: DomObject> LayoutDom<T> {
    /// Get the reflector.
    pub unsafe fn get_jsobject(&self) -> *mut JSObject {
        debug_assert!(thread_state::get().is_layout());
-        (*self.ptr.get()).reflector().get_jsobject().get()
+        (*self.ptr.as_ptr()).reflector().get_jsobject().get()
    }
 }

@ -420,7 +419,7 @@ impl<T> Copy for LayoutDom<T> {}

 impl<T> PartialEq for Dom<T> {
    fn eq(&self, other: &Dom<T>) -> bool {
-        self.ptr == other.ptr
+        self.ptr.as_ptr() == other.ptr.as_ptr()
    }
 }

@ -428,7 +427,7 @@ impl<T> Eq for Dom<T> {}

 impl<T> PartialEq for LayoutDom<T> {
    fn eq(&self, other: &LayoutDom<T>) -> bool {
-        self.ptr == other.ptr
+        self.ptr.as_ptr() == other.ptr.as_ptr()
    }
 }

@ -436,13 +435,13 @@ impl<T> Eq for LayoutDom<T> {}

 impl<T> Hash for Dom<T> {
    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.ptr.hash(state)
+        self.ptr.as_ptr().hash(state)
    }
 }

 impl<T> Hash for LayoutDom<T> {
    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.ptr.hash(state)
+        self.ptr.as_ptr().hash(state)
    }
 }

@ -474,7 +473,7 @@ impl LayoutDom<Node> {
        debug_assert!(thread_state::get().is_layout());
        let TrustedNodeAddress(addr) = inner;
        LayoutDom {
-            ptr: NonZero::new_unchecked(addr as *const Node),
+            ptr: ptr::NonNull::new_unchecked(addr as *const Node as *mut Node),
        }
    }
 }
@ -700,7 +699,7 @@ impl<T: DomObject> LayoutDom<T> {
    /// this is unsafe is what necessitates the layout wrappers.)
    pub unsafe fn unsafe_get(&self) -> *const T {
        debug_assert!(thread_state::get().is_layout());
-        self.ptr.get()
+        self.ptr.as_ptr()
    }

    /// Returns a reference to the interior of this JS object. This method is
@ -708,7 +707,7 @@ impl<T: DomObject> LayoutDom<T> {
    /// mutate DOM nodes.
    pub fn get_for_script(&self) -> &T {
        debug_assert!(thread_state::get().is_script());
-        unsafe { &*self.ptr.get() }
+        unsafe { &*self.ptr.as_ptr() }
    }
 }

--- a/servo/components/script/dom/bindings/weakref.rs
+++ b/servo/components/script/dom/bindings/weakref.rs
@ -18,10 +18,10 @@ use js::jsapi::{JSTracer, JS_GetReservedSlot, JS_SetReservedSlot};
 use js::jsval::PrivateValue;
 use libc::c_void;
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
-use nonzero::NonZero;
 use std::cell::{Cell, UnsafeCell};
 use std::mem;
 use std::ops::{Deref, DerefMut, Drop};
+use std::ptr;

 /// The index of the slot wherein a pointer to the weak holder cell is
 /// stored for weak-referenceable bindings. We use slot 1 for holding it,
@ -30,9 +30,10 @@ use std::ops::{Deref, DerefMut, Drop};
 pub const DOM_WEAK_SLOT: u32 = 1;

 /// A weak reference to a JS-managed DOM object.
+#[allow(unrooted_must_root)]
 #[allow_unrooted_interior]
 pub struct WeakRef<T: WeakReferenceable> {
-    ptr: NonZero<*mut WeakBox<T>>,
+    ptr: ptr::NonNull<WeakBox<T>>,
 }

 /// The inner box of weak references, public for the finalization in codegen.
@ -42,7 +43,7 @@ pub struct WeakBox<T: WeakReferenceable> {
    /// have already been set to `None`. The pointee contributes one to the count.
    pub count: Cell<usize>,
    /// The pointer to the JS-managed object, set to None when it is collected.
-    pub value: Cell<Option<NonZero<*const T>>>,
+    pub value: Cell<Option<ptr::NonNull<T>>>,
 }

 /// Trait implemented by weak-referenceable interfaces.
@ -58,7 +59,7 @@ pub trait WeakReferenceable: DomObject + Sized {
                trace!("Creating new WeakBox holder for {:p}.", self);
                ptr = Box::into_raw(Box::new(WeakBox {
                    count: Cell::new(1),
-                    value: Cell::new(Some(NonZero::new_unchecked(self))),
+                    value: Cell::new(Some(ptr::NonNull::from(self))),
                }));
                JS_SetReservedSlot(object, DOM_WEAK_SLOT, PrivateValue(ptr as *const c_void));
            }
@ -70,7 +71,7 @@ pub trait WeakReferenceable: DomObject + Sized {
                   new_count);
            box_.count.set(new_count);
            WeakRef {
-                ptr: NonZero::new_unchecked(ptr),
+                ptr: ptr::NonNull::new_unchecked(ptr),
            }
        }
    }
@ -86,21 +87,21 @@ impl<T: WeakReferenceable> WeakRef<T> {

    /// DomRoot a weak reference. Returns `None` if the object was already collected.
    pub fn root(&self) -> Option<DomRoot<T>> {
-        unsafe { &*self.ptr.get() }.value.get().map(|ptr| unsafe {
-            DomRoot::from_ref(&*ptr.get())
+        unsafe { &*self.ptr.as_ptr() }.value.get().map(|ptr| unsafe {
+            DomRoot::from_ref(&*ptr.as_ptr())
        })
    }

    /// Return whether the weakly-referenced object is still alive.
    pub fn is_alive(&self) -> bool {
-        unsafe { &*self.ptr.get() }.value.get().is_some()
+        unsafe { &*self.ptr.as_ptr() }.value.get().is_some()
    }
 }

 impl<T: WeakReferenceable> Clone for WeakRef<T> {
    fn clone(&self) -> WeakRef<T> {
        unsafe {
-            let box_ = &*self.ptr.get();
+            let box_ = &*self.ptr.as_ptr();
            let new_count = box_.count.get() + 1;
            box_.count.set(new_count);
            WeakRef {
@ -119,7 +120,8 @@ impl<T: WeakReferenceable> MallocSizeOf for WeakRef<T> {
 impl<T: WeakReferenceable> PartialEq for WeakRef<T> {
   fn eq(&self, other: &Self) -> bool {
        unsafe {
-            (*self.ptr.get()).value.get() == (*other.ptr.get()).value.get()
+            (*self.ptr.as_ptr()).value.get().map(ptr::NonNull::as_ptr) ==
+            (*other.ptr.as_ptr()).value.get().map(ptr::NonNull::as_ptr)
        }
    }
 }
@ -127,8 +129,8 @@ impl<T: WeakReferenceable> PartialEq for WeakRef<T> {
 impl<T: WeakReferenceable> PartialEq<T> for WeakRef<T> {
    fn eq(&self, other: &T) -> bool {
        unsafe {
-            match (*self.ptr.get()).value.get() {
-                Some(ptr) => ptr.get() == other,
+            match self.ptr.as_ref().value.get() {
+                Some(ptr) => ptr::eq(ptr.as_ptr(), other),
                None => false,
            }
        }
@ -145,7 +147,7 @@ impl<T: WeakReferenceable> Drop for WeakRef<T> {
    fn drop(&mut self) {
        unsafe {
            let (count, value) = {
-                let weak_box = &*self.ptr.get();
+                let weak_box = &*self.ptr.as_ptr();
                assert!(weak_box.count.get() > 0);
                let count = weak_box.count.get() - 1;
                weak_box.count.set(count);
@ -153,7 +155,7 @@ impl<T: WeakReferenceable> Drop for WeakRef<T> {
            };
            if count == 0 {
                assert!(value.is_none());
-                mem::drop(Box::from_raw(self.ptr.get()));
+                mem::drop(Box::from_raw(self.ptr.as_ptr()));
            }
        }
    }
--- a/servo/components/script/dom/crypto.rs
+++ b/servo/components/script/dom/crypto.rs
@ -6,7 +6,6 @@ use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::CryptoBinding;
 use dom::bindings::codegen::Bindings::CryptoBinding::CryptoMethods;
 use dom::bindings::error::{Error, Fallible};
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
 use dom::globalscope::GlobalScope;
@ -14,6 +13,7 @@ use dom_struct::dom_struct;
 use js::jsapi::{JSContext, JSObject};
 use js::jsapi::Type;
 use servo_rand::{ServoRng, Rng};
+use std::ptr::NonNull;

 unsafe_no_jsmanaged_fields!(ServoRng);

@ -44,7 +44,7 @@ impl CryptoMethods for Crypto {
    unsafe fn GetRandomValues(&self,
                       _cx: *mut JSContext,
                       input: *mut JSObject)
-                       -> Fallible<NonNullJSObjectPtr> {
+                       -> Fallible<NonNull<JSObject>> {
        assert!(!input.is_null());
        typedarray!(in(_cx) let mut array_buffer_view: ArrayBufferView = input);
        let (array_type, mut data) = match array_buffer_view.as_mut() {
@ -65,7 +65,7 @@ impl CryptoMethods for Crypto {

        self.rng.borrow_mut().fill_bytes(&mut data);

-        Ok(NonNullJSObjectPtr::new_unchecked(input))
+        Ok(NonNull::new_unchecked(input))
    }
 }

--- a/servo/components/script/dom/cssrulelist.rs
+++ b/servo/components/script/dom/cssrulelist.rs
@ -103,7 +103,7 @@ impl CSSRuleList {
        let parent_stylesheet = &*self.parent_stylesheet;
        let dom_rule = CSSRule::new_specific(&window, parent_stylesheet, new_rule);
        self.dom_rules.borrow_mut().insert(index, MutNullableDom::new(Some(&*dom_rule)));
-        Ok((idx))
+        Ok(idx)
    }

    // In case of a keyframe rule, index must be valid.
--- a/servo/components/script/dom/document.rs
+++ b/servo/components/script/dom/document.rs
@ -21,7 +21,6 @@ use dom::bindings::codegen::Bindings::WindowBinding::{FrameRequestCallback, Scro
 use dom::bindings::codegen::UnionTypes::NodeOrString;
 use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::inheritance::{Castable, ElementTypeId, HTMLElementTypeId, NodeTypeId};
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::refcounted::{Trusted, TrustedPromise};
 use dom::bindings::reflector::{DomObject, reflect_dom_object};
@ -96,7 +95,7 @@ use html5ever::{LocalName, Namespace, QualName};
 use hyper::header::{Header, SetCookie};
 use hyper_serde::Serde;
 use ipc_channel::ipc::{self, IpcSender};
-use js::jsapi::{JSContext, JSRuntime};
+use js::jsapi::{JSContext, JSObject, JSRuntime};
 use js::jsapi::JS_GetRuntime;
 use metrics::{InteractiveFlag, InteractiveMetrics, InteractiveWindow, ProfilerMetadataFactory, ProgressiveWebMetric};
 use msg::constellation_msg::{BrowsingContextId, Key, KeyModifiers, KeyState, TopLevelBrowsingContextId};
@ -125,6 +124,7 @@ use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::default::Default;
 use std::iter::once;
 use std::mem;
+use std::ptr::NonNull;
 use std::rc::Rc;
 use std::time::{Duration, Instant};
 use style::attr::AttrValue;
@ -3554,7 +3554,7 @@ impl DocumentMethods for Document {

    #[allow(unsafe_code)]
    // https://html.spec.whatwg.org/multipage/#dom-tree-accessors:dom-document-nameditem-filter
-    unsafe fn NamedGetter(&self, _cx: *mut JSContext, name: DOMString) -> Option<NonNullJSObjectPtr> {
+    unsafe fn NamedGetter(&self, _cx: *mut JSContext, name: DOMString) -> Option<NonNull<JSObject>> {
        #[derive(JSTraceable, MallocSizeOf)]
        struct NamedElementFilter {
            name: Atom,
@ -3611,7 +3611,7 @@ impl DocumentMethods for Document {
                if elements.peek().is_none() {
                    // TODO: Step 2.
                    // Step 3.
-                    return Some(NonNullJSObjectPtr::new_unchecked(first.reflector().get_jsobject().get()));
+                    return Some(NonNull::new_unchecked(first.reflector().get_jsobject().get()));
                }
            } else {
                return None;
@ -3622,7 +3622,7 @@ impl DocumentMethods for Document {
            name: name,
        };
        let collection = HTMLCollection::create(self.window(), root, Box::new(filter));
-        Some(NonNullJSObjectPtr::new_unchecked(collection.reflector().get_jsobject().get()))
+        Some(NonNull::new_unchecked(collection.reflector().get_jsobject().get()))
    }

    // https://html.spec.whatwg.org/multipage/#dom-tree-accessors:supported-property-names
--- a/servo/components/script/dom/gamepad.rs
+++ b/servo/components/script/dom/gamepad.rs
@ -5,7 +5,6 @@
 use dom::bindings::codegen::Bindings::GamepadBinding;
 use dom::bindings::codegen::Bindings::GamepadBinding::GamepadMethods;
 use dom::bindings::inheritance::Castable;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
@ -21,6 +20,7 @@ use js::jsapi::{Heap, JSContext, JSObject};
 use js::typedarray::{Float64Array, CreateWith};
 use std::cell::Cell;
 use std::ptr;
+use std::ptr::NonNull;
 use webvr_traits::{WebVRGamepadData, WebVRGamepadHand, WebVRGamepadState};

 #[dom_struct]
@ -131,8 +131,8 @@ impl GamepadMethods for Gamepad {

    #[allow(unsafe_code)]
    // https://w3c.github.io/gamepad/#dom-gamepad-axes
-    unsafe fn Axes(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
-        NonNullJSObjectPtr::new_unchecked(self.axes.get())
+    unsafe fn Axes(&self, _cx: *mut JSContext) -> NonNull<JSObject> {
+        NonNull::new_unchecked(self.axes.get())
    }

    // https://w3c.github.io/gamepad/#dom-gamepad-buttons
--- a/servo/components/script/dom/imagedata.rs
+++ b/servo/components/script/dom/imagedata.rs
@ -5,7 +5,6 @@
 use dom::bindings::codegen::Bindings::ImageDataBinding;
 use dom::bindings::codegen::Bindings::ImageDataBinding::ImageDataMethods;
 use dom::bindings::error::{Fallible, Error};
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
 use dom::globalscope::GlobalScope;
@ -16,6 +15,7 @@ use js::rust::Runtime;
 use js::typedarray::{Uint8ClampedArray, CreateWith};
 use std::default::Default;
 use std::ptr;
+use std::ptr::NonNull;
 use std::vec::Vec;

 #[dom_struct]
@ -159,8 +159,7 @@ impl ImageDataMethods for ImageData {

    #[allow(unsafe_code)]
    // https://html.spec.whatwg.org/multipage/#dom-imagedata-data
-    unsafe fn Data(&self, _: *mut JSContext) -> NonNullJSObjectPtr {
-        assert!(!self.data.get().is_null());
-        NonNullJSObjectPtr::new_unchecked(self.data.get())
+    unsafe fn Data(&self, _: *mut JSContext) -> NonNull<JSObject> {
+        NonNull::new(self.data.get()).expect("got a null pointer")
    }
 }
--- a/servo/components/script/dom/performanceobserver.rs
+++ b/servo/components/script/dom/performanceobserver.rs
@ -106,7 +106,7 @@ impl PerformanceObserverMethods for PerformanceObserver {
        // step 2
        // There must be at least one valid entry type.
        if entry_types.is_empty() {
-            return Err((Error::Type("entryTypes cannot be empty".to_string())));
+            return Err(Error::Type("entryTypes cannot be empty".to_string()));
        }

        // step 3-4-5
--- a/servo/components/script/dom/screen.rs
+++ b/servo/components/script/dom/screen.rs
@ -39,14 +39,14 @@ impl Screen {
        let (send, recv) = ipc::channel::<(Size2D<u32>)>().unwrap();
        self.window.upcast::<GlobalScope>()
            .script_to_constellation_chan().send(ScriptMsg::GetScreenSize(send)).unwrap();
-        recv.recv().unwrap_or((Size2D::zero()))
+        recv.recv().unwrap_or(Size2D::zero())
    }

    fn screen_avail_size(&self) -> Size2D<u32> {
        let (send, recv) = ipc::channel::<(Size2D<u32>)>().unwrap();
        self.window.upcast::<GlobalScope>()
            .script_to_constellation_chan().send(ScriptMsg::GetScreenAvailSize(send)).unwrap();
-        recv.recv().unwrap_or((Size2D::zero()))
+        recv.recv().unwrap_or(Size2D::zero())
    }
 }

--- a/servo/components/script/dom/testbinding.rs
+++ b/servo/components/script/dom/testbinding.rs
@ -21,7 +21,6 @@ use dom::bindings::codegen::UnionTypes::{StringOrLongSequence, StringOrStringSeq
 use dom::bindings::codegen::UnionTypes::{StringOrUnsignedLong, StringOrBoolean, UnsignedLongOrBoolean};
 use dom::bindings::error::{Error, Fallible};
 use dom::bindings::mozmap::MozMap;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::refcounted::TrustedPromise;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
@ -43,6 +42,7 @@ use script_traits::MsDuration;
 use servo_config::prefs::PREFS;
 use std::borrow::ToOwned;
 use std::ptr;
+use std::ptr::NonNull;
 use std::rc::Rc;
 use timers::OneshotTimerCallback;

@ -152,20 +152,18 @@ impl TestBindingMethods for TestBinding {
    }
    fn SetUnion9Attribute(&self, _: ByteStringOrLong) {}
    #[allow(unsafe_code)]
-    unsafe fn ArrayAttribute(&self, cx: *mut JSContext) -> NonNullJSObjectPtr {
+    unsafe fn ArrayAttribute(&self, cx: *mut JSContext) -> NonNull<JSObject> {
        rooted!(in(cx) let array = JS_NewUint8ClampedArray(cx, 16));
-        assert!(!array.is_null());
-        NonNullJSObjectPtr::new_unchecked(array.get())
+        NonNull::new(array.get()).expect("got a null pointer")
    }
    #[allow(unsafe_code)]
    unsafe fn AnyAttribute(&self, _: *mut JSContext) -> JSVal { NullValue() }
    #[allow(unsafe_code)]
    unsafe fn SetAnyAttribute(&self, _: *mut JSContext, _: HandleValue) {}
    #[allow(unsafe_code)]
-    unsafe fn ObjectAttribute(&self, cx: *mut JSContext) -> NonNullJSObjectPtr {
+    unsafe fn ObjectAttribute(&self, cx: *mut JSContext) -> NonNull<JSObject> {
        rooted!(in(cx) let obj = JS_NewPlainObject(cx));
-        assert!(!obj.is_null());
-        NonNullJSObjectPtr::new_unchecked(obj.get())
+        NonNull::new(obj.get()).expect("got a null pointer")
    }
    #[allow(unsafe_code)]
    unsafe fn SetObjectAttribute(&self, _: *mut JSContext, _: *mut JSObject) {}
@ -221,7 +219,7 @@ impl TestBindingMethods for TestBinding {
        self.url.set(url);
    }
    #[allow(unsafe_code)]
-    unsafe fn GetObjectAttributeNullable(&self, _: *mut JSContext) -> Option<NonNullJSObjectPtr> { None }
+    unsafe fn GetObjectAttributeNullable(&self, _: *mut JSContext) -> Option<NonNull<JSObject>> { None }
    #[allow(unsafe_code)]
    unsafe fn SetObjectAttributeNullable(&self, _: *mut JSContext, _: *mut JSObject) {}
    fn GetUnionAttributeNullable(&self) -> Option<HTMLElementOrLong> {
@ -273,7 +271,7 @@ impl TestBindingMethods for TestBinding {
    #[allow(unsafe_code)]
    unsafe fn ReceiveAny(&self, _: *mut JSContext) -> JSVal { NullValue() }
    #[allow(unsafe_code)]
-    unsafe fn ReceiveObject(&self, cx: *mut JSContext) -> NonNullJSObjectPtr {
+    unsafe fn ReceiveObject(&self, cx: *mut JSContext) -> NonNull<JSObject> {
        self.ObjectAttribute(cx)
    }
    fn ReceiveUnion(&self) -> HTMLElementOrLong { HTMLElementOrLong::Long(0) }
@ -317,7 +315,7 @@ impl TestBindingMethods for TestBinding {
        Some(Blob::new(&self.global(), BlobImpl::new_from_bytes(vec![]), "".to_owned()))
    }
    #[allow(unsafe_code)]
-    unsafe fn ReceiveNullableObject(&self, cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
+    unsafe fn ReceiveNullableObject(&self, cx: *mut JSContext) -> Option<NonNull<JSObject>> {
        self.GetObjectAttributeNullable(cx)
    }
    fn ReceiveNullableUnion(&self) -> Option<HTMLElementOrLong> {
--- a/servo/components/script/dom/textencoder.rs
+++ b/servo/components/script/dom/textencoder.rs
@ -5,7 +5,6 @@
 use dom::bindings::codegen::Bindings::TextEncoderBinding;
 use dom::bindings::codegen::Bindings::TextEncoderBinding::TextEncoderMethods;
 use dom::bindings::error::Fallible;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
 use dom::bindings::str::{DOMString, USVString};
@ -14,6 +13,7 @@ use dom_struct::dom_struct;
 use js::jsapi::{JSContext, JSObject};
 use js::typedarray::{Uint8Array, CreateWith};
 use std::ptr;
+use std::ptr::NonNull;

 #[dom_struct]
 pub struct TextEncoder {
@ -47,12 +47,12 @@ impl TextEncoderMethods for TextEncoder {

    #[allow(unsafe_code)]
    // https://encoding.spec.whatwg.org/#dom-textencoder-encode
-    unsafe fn Encode(&self, cx: *mut JSContext, input: USVString) -> NonNullJSObjectPtr {
+    unsafe fn Encode(&self, cx: *mut JSContext, input: USVString) -> NonNull<JSObject> {
        let encoded = input.0.as_bytes();

        rooted!(in(cx) let mut js_object = ptr::null_mut::<JSObject>());
        assert!(Uint8Array::create(cx, CreateWith::Slice(&encoded), js_object.handle_mut()).is_ok());

-        NonNullJSObjectPtr::new_unchecked(js_object.get())
+        NonNull::new_unchecked(js_object.get())
    }
 }
--- a/servo/components/script/dom/vreyeparameters.rs
+++ b/servo/components/script/dom/vreyeparameters.rs
@ -5,7 +5,6 @@
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::VREyeParametersBinding;
 use dom::bindings::codegen::Bindings::VREyeParametersBinding::VREyeParametersMethods;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
 use dom::globalscope::GlobalScope;
@ -15,6 +14,7 @@ use js::jsapi::{Heap, JSContext, JSObject};
 use js::typedarray::{Float32Array, CreateWith};
 use std::default::Default;
 use std::ptr;
+use std::ptr::NonNull;
 use webvr_traits::WebVREyeParameters;

 #[dom_struct]
@ -60,8 +60,8 @@ impl VREyeParameters {
 impl VREyeParametersMethods for VREyeParameters {
    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vreyeparameters-offset
-    unsafe fn Offset(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
-        NonNullJSObjectPtr::new_unchecked(self.offset.get())
+    unsafe fn Offset(&self, _cx: *mut JSContext) -> NonNull<JSObject> {
+        NonNull::new_unchecked(self.offset.get())
    }

    // https://w3c.github.io/webvr/#dom-vreyeparameters-fieldofview
--- a/servo/components/script/dom/vrframedata.rs
+++ b/servo/components/script/dom/vrframedata.rs
@ -5,7 +5,6 @@
 use dom::bindings::codegen::Bindings::VRFrameDataBinding;
 use dom::bindings::codegen::Bindings::VRFrameDataBinding::VRFrameDataMethods;
 use dom::bindings::error::Fallible;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
@ -17,6 +16,7 @@ use js::jsapi::{Heap, JSContext, JSObject};
 use js::typedarray::{Float32Array, CreateWith};
 use std::cell::Cell;
 use std::ptr;
+use std::ptr::NonNull;
 use webvr_traits::WebVRFrameData;

 #[dom_struct]
@ -118,26 +118,26 @@ impl VRFrameDataMethods for VRFrameData {

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrframedata-leftprojectionmatrix
-    unsafe fn LeftProjectionMatrix(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
-        NonNullJSObjectPtr::new_unchecked(self.left_proj.get())
+    unsafe fn LeftProjectionMatrix(&self, _cx: *mut JSContext) -> NonNull<JSObject> {
+        NonNull::new_unchecked(self.left_proj.get())
    }

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrframedata-leftviewmatrix
-    unsafe fn LeftViewMatrix(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
-        NonNullJSObjectPtr::new_unchecked(self.left_view.get())
+    unsafe fn LeftViewMatrix(&self, _cx: *mut JSContext) -> NonNull<JSObject> {
+        NonNull::new_unchecked(self.left_view.get())
    }

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrframedata-rightprojectionmatrix
-    unsafe fn RightProjectionMatrix(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
-        NonNullJSObjectPtr::new_unchecked(self.right_proj.get())
+    unsafe fn RightProjectionMatrix(&self, _cx: *mut JSContext) -> NonNull<JSObject> {
+        NonNull::new_unchecked(self.right_proj.get())
    }

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrframedata-rightviewmatrix
-    unsafe fn RightViewMatrix(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
-        NonNullJSObjectPtr::new_unchecked(self.right_view.get())
+    unsafe fn RightViewMatrix(&self, _cx: *mut JSContext) -> NonNull<JSObject> {
+        NonNull::new_unchecked(self.right_view.get())
    }

    // https://w3c.github.io/webvr/#dom-vrframedata-pose
--- a/servo/components/script/dom/vrpose.rs
+++ b/servo/components/script/dom/vrpose.rs
@ -4,7 +4,6 @@

 use dom::bindings::codegen::Bindings::VRPoseBinding;
 use dom::bindings::codegen::Bindings::VRPoseBinding::VRPoseMethods;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
 use dom::globalscope::GlobalScope;
@ -12,6 +11,7 @@ use dom_struct::dom_struct;
 use js::jsapi::{Heap, JSContext, JSObject};
 use js::typedarray::{Float32Array, CreateWith};
 use std::ptr;
+use std::ptr::NonNull;
 use webvr_traits::webvr;

 #[dom_struct]
@ -52,13 +52,13 @@ unsafe fn update_or_create_typed_array(cx: *mut JSContext,

 #[inline]
 #[allow(unsafe_code)]
-fn heap_to_option(heap: &Heap<*mut JSObject>) -> Option<NonNullJSObjectPtr> {
+fn heap_to_option(heap: &Heap<*mut JSObject>) -> Option<NonNull<JSObject>> {
    let js_object = heap.get();
    if js_object.is_null() {
        None
    } else {
        unsafe {
-            Some(NonNullJSObjectPtr::new_unchecked(js_object))
+            Some(NonNull::new_unchecked(js_object))
        }
    }
 }
@ -101,37 +101,37 @@ impl VRPose {
 impl VRPoseMethods for VRPose {
    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrpose-position
-    unsafe fn GetPosition(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
+    unsafe fn GetPosition(&self, _cx: *mut JSContext) -> Option<NonNull<JSObject>> {
        heap_to_option(&self.position)
    }

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrpose-linearvelocity
-    unsafe fn GetLinearVelocity(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
+    unsafe fn GetLinearVelocity(&self, _cx: *mut JSContext) -> Option<NonNull<JSObject>> {
        heap_to_option(&self.linear_vel)
    }

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrpose-linearacceleration
-    unsafe fn GetLinearAcceleration(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
+    unsafe fn GetLinearAcceleration(&self, _cx: *mut JSContext) -> Option<NonNull<JSObject>> {
        heap_to_option(&self.linear_acc)
    }

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrpose-orientation
-    unsafe fn GetOrientation(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
+    unsafe fn GetOrientation(&self, _cx: *mut JSContext) -> Option<NonNull<JSObject>> {
        heap_to_option(&self.orientation)
    }

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrpose-angularvelocity
-    unsafe fn GetAngularVelocity(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
+    unsafe fn GetAngularVelocity(&self, _cx: *mut JSContext) -> Option<NonNull<JSObject>> {
        heap_to_option(&self.angular_vel)
    }

    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrpose-angularacceleration
-    unsafe fn GetAngularAcceleration(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
+    unsafe fn GetAngularAcceleration(&self, _cx: *mut JSContext) -> Option<NonNull<JSObject>> {
        heap_to_option(&self.angular_acc)
    }
 }
--- a/servo/components/script/dom/vrstageparameters.rs
+++ b/servo/components/script/dom/vrstageparameters.rs
@ -5,7 +5,6 @@
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::VRStageParametersBinding;
 use dom::bindings::codegen::Bindings::VRStageParametersBinding::VRStageParametersMethods;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
@ -14,6 +13,7 @@ use dom_struct::dom_struct;
 use js::jsapi::{Heap, JSContext, JSObject};
 use js::typedarray::{Float32Array, CreateWith};
 use std::ptr;
+use std::ptr::NonNull;
 use webvr_traits::WebVRStageParameters;

 #[dom_struct]
@ -69,8 +69,8 @@ impl VRStageParameters {
 impl VRStageParametersMethods for VRStageParameters {
    #[allow(unsafe_code)]
    // https://w3c.github.io/webvr/#dom-vrstageparameters-sittingtostandingtransform
-    unsafe fn SittingToStandingTransform(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
-        NonNullJSObjectPtr::new_unchecked(self.transform.get())
+    unsafe fn SittingToStandingTransform(&self, _cx: *mut JSContext) -> NonNull<JSObject> {
+        NonNull::new_unchecked(self.transform.get())
    }

    // https://w3c.github.io/webvr/#dom-vrstageparameters-sizex
--- a/servo/components/script/dom/webgl2renderingcontext.rs
+++ b/servo/components/script/dom/webgl2renderingcontext.rs
@ -10,7 +10,6 @@ use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLContext
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextMethods;
 use dom::bindings::codegen::UnionTypes::ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement;
 use dom::bindings::error::Fallible;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{reflect_dom_object, Reflector};
 use dom::bindings::root::{Dom, DomRoot, LayoutDom};
 use dom::bindings::str::DOMString;
@ -33,6 +32,7 @@ use js::jsapi::{JSContext, JSObject};
 use js::jsval::JSVal;
 use offscreen_gl_context::GLContextAttributes;
 use script_layout_interface::HTMLCanvasDataSource;
+use std::ptr::NonNull;

 #[dom_struct]
 pub struct WebGL2RenderingContext {
@ -132,7 +132,7 @@ impl WebGL2RenderingContextMethods for WebGL2RenderingContext {

    #[allow(unsafe_code)]
    /// https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.14
-    unsafe fn GetExtension(&self, cx: *mut JSContext, name: DOMString) -> Option<NonNullJSObjectPtr> {
+    unsafe fn GetExtension(&self, cx: *mut JSContext, name: DOMString) -> Option<NonNull<JSObject>> {
        self.base.GetExtension(cx, name)
    }

--- a/servo/components/script/dom/webgl_extensions/extensions.rs
+++ b/servo/components/script/dom/webgl_extensions/extensions.rs
@ -7,19 +7,20 @@ use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::OESStandardDerivativesBinding::OESStandardDerivativesConstants;
 use dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::OESTextureHalfFloatConstants;
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::root::DomRoot;
 use dom::bindings::trace::JSTraceable;
 use dom::webglrenderingcontext::WebGLRenderingContext;
 use fnv::{FnvHashMap, FnvHashSet};
 use gleam::gl::GLenum;
 use js::jsapi::JSContext;
+use js::jsapi::JSObject;
 use js::jsval::JSVal;
 use malloc_size_of::MallocSizeOf;
 use ref_filter_map::ref_filter_map;
 use std::cell::Ref;
 use std::collections::HashMap;
 use std::iter::FromIterator;
+use std::ptr::NonNull;
 use super::{ext, WebGLExtension, WebGLExtensionSpec};
 use super::wrapper::{WebGLExtensionWrapper, TypedWebGLExtensionWrapper};

@ -127,7 +128,7 @@ impl WebGLExtensions {
                                .collect()
    }

-    pub fn get_or_init_extension(&self, name: &str, ctx: &WebGLRenderingContext) -> Option<NonNullJSObjectPtr> {
+    pub fn get_or_init_extension(&self, name: &str, ctx: &WebGLRenderingContext) -> Option<NonNull<JSObject>> {
        let name = name.to_uppercase();
        self.extensions.borrow().get(&name).and_then(|extension| {
            if extension.is_supported(self) {
--- a/servo/components/script/dom/webgl_extensions/wrapper.rs
+++ b/servo/components/script/dom/webgl_extensions/wrapper.rs
@ -2,13 +2,14 @@
 * 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/. */

-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::DomObject;
 use dom::bindings::root::{DomRoot, MutNullableDom};
 use dom::bindings::trace::JSTraceable;
 use dom::webglrenderingcontext::WebGLRenderingContext;
+use js::jsapi::JSObject;
 use malloc_size_of::MallocSizeOf;
 use std::any::Any;
+use std::ptr::NonNull;
 use super::{WebGLExtension, WebGLExtensions, WebGLExtensionSpec};

 /// Trait used internally by WebGLExtensions to store and
@ -17,7 +18,7 @@ pub trait WebGLExtensionWrapper: JSTraceable + MallocSizeOf {
    fn instance_or_init(&self,
                        ctx: &WebGLRenderingContext,
                        ext: &WebGLExtensions)
-                        -> NonNullJSObjectPtr;
+                        -> NonNull<JSObject>;
    fn spec(&self) -> WebGLExtensionSpec;
    fn is_supported(&self, &WebGLExtensions) -> bool;
    fn is_enabled(&self) -> bool;
@ -48,7 +49,7 @@ impl<T> WebGLExtensionWrapper for TypedWebGLExtensionWrapper<T>
    fn instance_or_init(&self,
                        ctx: &WebGLRenderingContext,
                        ext: &WebGLExtensions)
-                        -> NonNullJSObjectPtr {
+                        -> NonNull<JSObject> {
        let mut enabled = true;
        let extension = self.extension.or_init(|| {
            enabled = false;
@ -58,7 +59,7 @@ impl<T> WebGLExtensionWrapper for TypedWebGLExtensionWrapper<T>
            self.enable(ext);
        }
        unsafe {
-            NonNullJSObjectPtr::new_unchecked(extension.reflector().get_jsobject().get())
+            NonNull::new_unchecked(extension.reflector().get_jsobject().get())
        }
    }

--- a/servo/components/script/dom/webglrenderingcontext.rs
+++ b/servo/components/script/dom/webglrenderingcontext.rs
@ -17,7 +17,6 @@ use dom::bindings::codegen::UnionTypes::ImageDataOrHTMLImageElementOrHTMLCanvasE
 use dom::bindings::conversions::{ConversionResult, FromJSValConvertible, ToJSValConvertible};
 use dom::bindings::error::{Error, Fallible};
 use dom::bindings::inheritance::Castable;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot, LayoutDom, MutNullableDom};
 use dom::bindings::str::DOMString;
@ -57,6 +56,7 @@ use script_layout_interface::HTMLCanvasDataSource;
 use servo_config::prefs::PREFS;
 use std::cell::{Cell, Ref};
 use std::iter::FromIterator;
+use std::ptr::NonNull;
 use webrender_api;

 type ImagePixelResult = Result<(Vec<u8>, Size2D<i32>, bool), ()>;
@ -1389,7 +1389,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
    #[allow(unsafe_code)]
    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.14
    unsafe fn GetExtension(&self, _cx: *mut JSContext, name: DOMString)
-                    -> Option<NonNullJSObjectPtr> {
+                    -> Option<NonNull<JSObject>> {
        self.extension_manager.init_once(|| {
            self.get_gl_extensions()
        });
--- a/servo/components/script/dom/xmldocument.rs
+++ b/servo/components/script/dom/xmldocument.rs
@ -6,7 +6,6 @@ use document_loader::DocumentLoader;
 use dom::bindings::codegen::Bindings::DocumentBinding::DocumentMethods;
 use dom::bindings::codegen::Bindings::XMLDocumentBinding::{self, XMLDocumentMethods};
 use dom::bindings::inheritance::Castable;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::reflect_dom_object;
 use dom::bindings::root::DomRoot;
 use dom::bindings::str::DOMString;
@ -16,8 +15,10 @@ use dom::node::Node;
 use dom::window::Window;
 use dom_struct::dom_struct;
 use js::jsapi::JSContext;
+use js::jsapi::JSObject;
 use script_traits::DocumentActivity;
 use servo_url::{MutableOrigin, ServoUrl};
+use std::ptr::NonNull;

 // https://dom.spec.whatwg.org/#xmldocument
 #[dom_struct]
@ -101,7 +102,7 @@ impl XMLDocumentMethods for XMLDocument {

    #[allow(unsafe_code)]
    // https://html.spec.whatwg.org/multipage/#dom-tree-accessors:dom-document-nameditem-filter
-    unsafe fn NamedGetter(&self, _cx: *mut JSContext, name: DOMString) -> Option<NonNullJSObjectPtr> {
+    unsafe fn NamedGetter(&self, _cx: *mut JSContext, name: DOMString) -> Option<NonNull<JSObject>> {
        self.upcast::<Document>().NamedGetter(_cx, name)
    }
 }
--- a/servo/components/script/dom/xmlhttprequest.rs
+++ b/servo/components/script/dom/xmlhttprequest.rs
@ -14,7 +14,6 @@ use dom::bindings::codegen::UnionTypes::DocumentOrBodyInit;
 use dom::bindings::conversions::ToJSValConvertible;
 use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::inheritance::Castable;
-use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::refcounted::Trusted;
 use dom::bindings::reflector::{DomObject, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot, MutNullableDom};
@ -67,6 +66,7 @@ use std::borrow::ToOwned;
 use std::cell::Cell;
 use std::default::Default;
 use std::ptr;
+use std::ptr::NonNull;
 use std::slice;
 use std::str;
 use std::sync::{Arc, Mutex};
@ -1120,11 +1120,11 @@ impl XMLHttpRequest {

    // https://xhr.spec.whatwg.org/#arraybuffer-response
    #[allow(unsafe_code)]
-    unsafe fn arraybuffer_response(&self, cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
+    unsafe fn arraybuffer_response(&self, cx: *mut JSContext) -> Option<NonNull<JSObject>> {
        // Step 1
        let created = self.response_arraybuffer.get();
-        if !created.is_null() {
-            return Some(NonNullJSObjectPtr::new_unchecked(created));
+        if let Some(nonnull) = NonNull::new(created) {
+            return Some(nonnull)
        }

        // Step 2
@ -1132,7 +1132,7 @@ impl XMLHttpRequest {
        rooted!(in(cx) let mut array_buffer = ptr::null_mut::<JSObject>());
        ArrayBuffer::create(cx, CreateWith::Slice(&bytes), array_buffer.handle_mut()).ok().and_then(|()| {
            self.response_arraybuffer.set(array_buffer.get());
-            Some(NonNullJSObjectPtr::new_unchecked(array_buffer.get()))
+            Some(NonNull::new_unchecked(array_buffer.get()))
        })
    }

--- a/servo/components/script/lib.rs
+++ b/servo/components/script/lib.rs
@ -68,7 +68,6 @@ extern crate mitochondria;
 extern crate mozjs as js;
 extern crate msg;
 extern crate net_traits;
-extern crate nonzero;
 extern crate num_traits;
 extern crate offscreen_gl_context;
 extern crate open;
--- a/servo/components/script_layout_interface/Cargo.toml
+++ b/servo/components/script_layout_interface/Cargo.toml
@ -25,7 +25,6 @@ malloc_size_of_derive = { path = "../malloc_size_of_derive" }
 metrics = {path = "../metrics"}
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
-nonzero = {path = "../nonzero"}
 profile_traits = {path = "../profile_traits"}
 range = {path = "../range"}
 script_traits = {path = "../script_traits"}
--- a/servo/components/script_layout_interface/lib.rs
+++ b/servo/components/script_layout_interface/lib.rs
@ -24,7 +24,6 @@ extern crate malloc_size_of;
 extern crate metrics;
 extern crate msg;
 extern crate net_traits;
-extern crate nonzero;
 extern crate profile_traits;
 extern crate range;
 extern crate script_traits;
@ -45,9 +44,9 @@ use canvas_traits::canvas::CanvasMsg;
 use ipc_channel::ipc::IpcSender;
 use libc::c_void;
 use net_traits::image_cache::PendingImageId;
-use nonzero::NonZero;
 use script_traits::UntrustedNodeAddress;
 use servo_url::ServoUrl;
+use std::ptr::NonNull;
 use std::sync::atomic::AtomicIsize;
 use style::data::ElementData;

@ -77,7 +76,7 @@ pub struct OpaqueStyleAndLayoutData {
    // NB: We really store a `StyleAndLayoutData` here, so be careful!
    #[ignore_malloc_size_of = "TODO(#6910) Box value that should be counted but \
                               the type lives in layout"]
-    pub ptr: NonZero<*mut StyleData>,
+    pub ptr: NonNull<StyleData>,
 }

 #[allow(unsafe_code)]
--- a/servo/components/servo_arc/lib.rs
+++ b/servo/components/servo_arc/lib.rs
@ -83,6 +83,7 @@ const MAX_REFCOUNT: usize = (isize::MAX) as usize;
 /// that this is all a temporary hack, this restriction is fine for now.
 ///
 /// [1]: https://github.com/rust-lang/rust/issues/27730
+// FIXME: remove this and use std::ptr::NonNull when Firefox requires Rust 1.25+
 pub struct NonZeroPtrMut<T: ?Sized + 'static>(&'static mut T);
 impl<T: ?Sized> NonZeroPtrMut<T> {
    pub fn new(ptr: *mut T) -> Self {
--- a/servo/components/style/rule_tree/mod.rs
+++ b/servo/components/style/rule_tree/mod.rs
@ -828,6 +828,8 @@ impl MallocSizeOf for RuleNode {
    }
 }

+// FIXME: use std::ptr::NonNull when Firefox requires Rust 1.25+
+
 #[derive(Clone)]
 struct WeakRuleNode {
    p: NonZeroPtrMut<RuleNode>,
--- a/servo/ports/cef/eutil.rs
+++ b/servo/ports/cef/eutil.rs
@ -30,7 +30,7 @@ pub fn slice_to_str<F>(s: *const u8, l: usize, f: F) -> c_int where F: FnOnce(&s
 /// All fields are initialized to zero. It is the caller's responsibility to ensure that the given
 /// type is a CEF type with `cef_base_t` as its first member.
 pub unsafe fn create_cef_object<Base,Extra>(size: size_t) -> *mut Base {
-    let object = libc::calloc(1, (mem::size_of::<Base>() + mem::size_of::<Extra>())) as
+    let object = libc::calloc(1, mem::size_of::<Base>() + mem::size_of::<Extra>()) as
        *mut cef_base_t;
    (*object).size = size;
    (*object).add_ref = Some(servo_add_ref as extern "C" fn(*mut cef_base_t) -> c_int);
--- a/servo/ports/cef/wrappers.rs
+++ b/servo/ports/cef/wrappers.rs
@ -199,7 +199,7 @@ cef_unimplemented_wrapper!(cef_string_t, String);
 impl<'a> CefWrap<*const cef_string_t> for &'a [u16] {
    fn to_c(buffer: &'a [u16]) -> *const cef_string_t {
        unsafe {
-            let ptr = libc::malloc(((buffer.len() + 1) * 2)) as *mut c_ushort;
+            let ptr = libc::malloc((buffer.len() + 1) * 2) as *mut c_ushort;
            ptr::copy(buffer.as_ptr(), ptr, buffer.len());
            *ptr.offset(buffer.len() as isize) = 0;

--- a/servo/ports/geckolib/glue.rs
+++ b/servo/ports/geckolib/glue.rs
@ -4396,7 +4396,7 @@ pub extern "C" fn Servo_GetCustomPropertyValue(
        None => return false,
    };

-    let name = unsafe { Atom::from((&*name)) };
+    let name = unsafe { Atom::from(&*name) };
    let computed_value = match custom_properties.get(&name) {
        Some(v) => v,
        None => return false,
--- a/servo/rust-toolchain
+++ b/servo/rust-toolchain
@ -1 +1 @@
-nightly-2018-01-14
+nightly-2018-01-21