firefox/mozilla-1337988.patch

diff -up firefox-55.0/dom/plugins/base/nsJSNPRuntime.cpp.1337988 firefox-55.0/dom/plugins/base/nsJSNPRuntime.cpp
--- firefox-55.0/dom/plugins/base/nsJSNPRuntime.cpp.1337988	2017-07-31 18:20:53.000000000 +0200
+++ firefox-55.0/dom/plugins/base/nsJSNPRuntime.cpp	2017-08-02 14:33:41.736715482 +0200
@@ -1766,7 +1766,7 @@ NPObjWrapper_ObjectMoved(JSObject *obj,
   auto entry =
     static_cast<NPObjWrapperHashEntry*>(sNPObjWrappers->Search(npobj));
   MOZ_ASSERT(entry && entry->mJSObj);
-  MOZ_ASSERT(entry->mJSObj == old);
+  MOZ_ASSERT(entry->mJSObj.unbarrieredGetPtr() == old);
   entry->mJSObj = obj;
 }
 
diff -up firefox-55.0/js/ipc/JavaScriptShared.cpp.1337988 firefox-55.0/js/ipc/JavaScriptShared.cpp
--- firefox-55.0/js/ipc/JavaScriptShared.cpp.1337988	2017-07-31 18:20:47.000000000 +0200
+++ firefox-55.0/js/ipc/JavaScriptShared.cpp	2017-08-02 14:33:41.736715482 +0200
@@ -101,7 +101,7 @@ IdToObjectMap::has(const ObjectId& id, c
     auto p = table_.lookup(id);
     if (!p)
         return false;
-    return p->value() == obj;
+    return p->value().unbarrieredGet() == obj;
 }
 #endif
 
diff -up firefox-55.0/js/public/RootingAPI.h.1337988 firefox-55.0/js/public/RootingAPI.h
--- firefox-55.0/js/public/RootingAPI.h.1337988	2017-07-31 18:20:47.000000000 +0200
+++ firefox-55.0/js/public/RootingAPI.h	2017-08-02 15:20:44.873663128 +0200
@@ -148,6 +148,10 @@ template<typename T>
 struct PersistentRootedMarker;
 } /* namespace gc */
 
+#define DECLARE_POINTER_COMPARISON_OPS(T)                                                         \
+    bool operator==(const T& other) const { return get() == other; }                              \
+    bool operator!=(const T& other) const { return get() != other; }
+
 // Important: Return a reference so passing a Rooted<T>, etc. to
 // something that takes a |const T&| is not a GC hazard.
 #define DECLARE_POINTER_CONSTREF_OPS(T)                                                           \
@@ -237,8 +241,6 @@ class Heap : public js::HeapBase<T, Heap
     static_assert(js::IsHeapConstructibleType<T>::value,
                   "Type T must be a public GC pointer type");
   public:
-    using ElementType = T;
-
     Heap() {
         static_assert(sizeof(T) == sizeof(Heap<T>),
                       "Heap<T> must be binary compatible with T.");
@@ -385,8 +387,6 @@ template <typename T>
 class TenuredHeap : public js::HeapBase<T, TenuredHeap<T>>
 {
   public:
-    using ElementType = T;
-
     TenuredHeap() : bits(0) {
         static_assert(sizeof(T) == sizeof(TenuredHeap<T>),
                       "TenuredHeap<T> must be binary compatible with T.");
@@ -394,6 +394,9 @@ class TenuredHeap : public js::HeapBase<
     explicit TenuredHeap(T p) : bits(0) { setPtr(p); }
     explicit TenuredHeap(const TenuredHeap<T>& p) : bits(0) { setPtr(p.getPtr()); }
 
+    bool operator==(const TenuredHeap<T>& other) { return bits == other.bits; }
+    bool operator!=(const TenuredHeap<T>& other) { return bits != other.bits; }
+
     void setPtr(T newPtr) {
         MOZ_ASSERT((reinterpret_cast<uintptr_t>(newPtr) & flagsMask) == 0);
         if (newPtr)
@@ -470,8 +473,6 @@ class MOZ_NONHEAP_CLASS Handle : public
     friend class JS::MutableHandle<T>;
 
   public:
-    using ElementType = T;
-
     /* Creates a handle from a handle of a type convertible to T. */
     template <typename S>
     MOZ_IMPLICIT Handle(Handle<S> handle,
@@ -533,6 +534,7 @@ class MOZ_NONHEAP_CLASS Handle : public
     MOZ_IMPLICIT Handle(MutableHandle<S>& root,
                         typename mozilla::EnableIf<mozilla::IsConvertible<S, T>::value, int>::Type dummy = 0);
 
+    DECLARE_POINTER_COMPARISON_OPS(T);
     DECLARE_POINTER_CONSTREF_OPS(T);
     DECLARE_NONPOINTER_ACCESSOR_METHODS(*ptr);
 
@@ -559,8 +561,6 @@ template <typename T>
 class MOZ_STACK_CLASS MutableHandle : public js::MutableHandleBase<T, MutableHandle<T>>
 {
   public:
-    using ElementType = T;
-
     inline MOZ_IMPLICIT MutableHandle(Rooted<T>* root);
     inline MOZ_IMPLICIT MutableHandle(PersistentRooted<T>* root);
 
@@ -589,6 +589,7 @@ class MOZ_STACK_CLASS MutableHandle : pu
         return h;
     }
 
+    DECLARE_POINTER_COMPARISON_OPS(T);
     DECLARE_POINTER_CONSTREF_OPS(T);
     DECLARE_NONPOINTER_ACCESSOR_METHODS(*ptr);
     DECLARE_NONPOINTER_MUTABLE_ACCESSOR_METHODS(*ptr);
@@ -805,8 +806,6 @@ class MOZ_RAII Rooted : public js::Roote
     }
 
   public:
-    using ElementType = T;
-
     template <typename RootingContext>
     explicit Rooted(const RootingContext& cx)
       : ptr(GCPolicy<T>::initial())
@@ -839,6 +838,7 @@ class MOZ_RAII Rooted : public js::Roote
         ptr = mozilla::Move(value);
     }
 
+    DECLARE_POINTER_COMPARISON_OPS(T);
     DECLARE_POINTER_CONSTREF_OPS(T);
     DECLARE_POINTER_ASSIGN_OPS(Rooted, T);
     DECLARE_NONPOINTER_ACCESSOR_METHODS(ptr);
@@ -903,14 +903,13 @@ template <typename T>
 class MOZ_RAII FakeRooted : public RootedBase<T, FakeRooted<T>>
 {
   public:
-    using ElementType = T;
-
     template <typename CX>
     explicit FakeRooted(CX* cx) : ptr(JS::GCPolicy<T>::initial()) {}
 
     template <typename CX>
     FakeRooted(CX* cx, T initial) : ptr(initial) {}
 
+    DECLARE_POINTER_COMPARISON_OPS(T);
     DECLARE_POINTER_CONSTREF_OPS(T);
     DECLARE_POINTER_ASSIGN_OPS(FakeRooted, T);
     DECLARE_NONPOINTER_ACCESSOR_METHODS(ptr);
@@ -931,8 +930,6 @@ template <typename T>
 class FakeMutableHandle : public js::MutableHandleBase<T, FakeMutableHandle<T>>
 {
   public:
-    using ElementType = T;
-
     MOZ_IMPLICIT FakeMutableHandle(T* t) {
         ptr = t;
     }
@@ -1124,8 +1121,6 @@ class PersistentRooted : public js::Root
     }
 
   public:
-    using ElementType = T;
-
     PersistentRooted() : ptr(GCPolicy<T>::initial()) {}
 
     explicit PersistentRooted(RootingContext* cx)
@@ -1203,6 +1198,7 @@ class PersistentRooted : public js::Root
         }
     }
 
+    DECLARE_POINTER_COMPARISON_OPS(T);
     DECLARE_POINTER_CONSTREF_OPS(T);
     DECLARE_POINTER_ASSIGN_OPS(PersistentRooted, T);
     DECLARE_NONPOINTER_ACCESSOR_METHODS(ptr);
@@ -1234,8 +1230,6 @@ class JS_PUBLIC_API(ObjectPtr)
     Heap<JSObject*> value;
 
   public:
-    using ElementType = JSObject*;
-
     ObjectPtr() : value(nullptr) {}
 
     explicit ObjectPtr(JSObject* obj) : value(obj) {}
@@ -1342,177 +1336,6 @@ Swap(JS::TenuredHeap<T>& aX, JS::Tenured
 
 } /* namespace mozilla */
 
-namespace js {
-namespace detail {
-
-// DefineComparisonOps is a trait which selects which wrapper classes to define
-// operator== and operator!= for. It supplies a getter function to extract the
-// value to compare. This is used to avoid triggering the automatic read
-// barriers where appropriate.
-//
-// If DefineComparisonOps is not specialized for a particular wrapper you may
-// get errors such as 'invalid operands to binary expression' or 'no match for
-// operator==' when trying to compare against instances of the wrapper.
-
-template <typename T>
-struct DefineComparisonOps : mozilla::FalseType {};
-
-template <typename T>
-struct DefineComparisonOps<JS::Heap<T>> : mozilla::TrueType {
-    static const T& get(const JS::Heap<T>& v) { return v.unbarrieredGet(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<JS::TenuredHeap<T>> : mozilla::TrueType {
-    static const T get(const JS::TenuredHeap<T>& v) { return v.unbarrieredGetPtr(); }
-};
-
-template <>
-struct DefineComparisonOps<JS::ObjectPtr> : mozilla::TrueType {
-    static const JSObject* get(const JS::ObjectPtr& v) { return v.unbarrieredGet(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<JS::Rooted<T>> : mozilla::TrueType {
-    static const T& get(const JS::Rooted<T>& v) { return v.get(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<JS::Handle<T>> : mozilla::TrueType {
-    static const T& get(const JS::Handle<T>& v) { return v.get(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<JS::MutableHandle<T>> : mozilla::TrueType {
-    static const T& get(const JS::MutableHandle<T>& v) { return v.get(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<JS::PersistentRooted<T>> : mozilla::TrueType {
-    static const T& get(const JS::PersistentRooted<T>& v) { return v.get(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<js::FakeRooted<T>> : mozilla::TrueType {
-    static const T& get(const js::FakeRooted<T>& v) { return v.get(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<js::FakeMutableHandle<T>> : mozilla::TrueType {
-    static const T& get(const js::FakeMutableHandle<T>& v) { return v.get(); }
-};
-
-} /* namespace detail */
-} /* namespace js */
-
-// Overload operator== and operator!= for all types with the DefineComparisonOps
-// trait using the supplied getter.
-//
-// There are four cases:
-
-// Case 1: comparison between two wrapper objects.
-
-template <typename T, typename U>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           js::detail::DefineComparisonOps<U>::value, bool>::Type
-operator==(const T& a, const U& b) {
-    return js::detail::DefineComparisonOps<T>::get(a) == js::detail::DefineComparisonOps<U>::get(b);
-}
-
-template <typename T, typename U>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           js::detail::DefineComparisonOps<U>::value, bool>::Type
-operator!=(const T& a, const U& b) {
-    return !(a == b);
-}
-
-// Case 2: comparison between a wrapper object and its unwrapped element type.
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value, bool>::Type
-operator==(const T& a, const typename T::ElementType& b) {
-    return js::detail::DefineComparisonOps<T>::get(a) == b;
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value, bool>::Type
-operator!=(const T& a, const typename T::ElementType& b) {
-    return !(a == b);
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value, bool>::Type
-operator==(const typename T::ElementType& a, const T& b) {
-    return a == js::detail::DefineComparisonOps<T>::get(b);
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value, bool>::Type
-operator!=(const typename T::ElementType& a, const T& b) {
-    return !(a == b);
-}
-
-// Case 3: For pointer wrappers, comparison between the wrapper and a const
-// element pointer.
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           mozilla::IsPointer<typename T::ElementType>::value, bool>::Type
-operator==(const typename mozilla::RemovePointer<typename T::ElementType>::Type* a, const T& b) {
-    return a == js::detail::DefineComparisonOps<T>::get(b);
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           mozilla::IsPointer<typename T::ElementType>::value, bool>::Type
-operator!=(const typename mozilla::RemovePointer<typename T::ElementType>::Type* a, const T& b) {
-    return !(a == b);
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           mozilla::IsPointer<typename T::ElementType>::value, bool>::Type
-operator==(const T& a, const typename mozilla::RemovePointer<typename T::ElementType>::Type* b) {
-    return js::detail::DefineComparisonOps<T>::get(a) == b;
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           mozilla::IsPointer<typename T::ElementType>::value, bool>::Type
-operator!=(const T& a, const typename mozilla::RemovePointer<typename T::ElementType>::Type* b) {
-    return !(a == b);
-}
-
-// Case 4: For pointer wrappers, comparison between the wrapper and nullptr.
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           mozilla::IsPointer<typename T::ElementType>::value, bool>::Type
-operator==(std::nullptr_t a, const T& b) {
-    return a == js::detail::DefineComparisonOps<T>::get(b);
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           mozilla::IsPointer<typename T::ElementType>::value, bool>::Type
-operator!=(std::nullptr_t a, const T& b) {
-    return !(a == b);
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           mozilla::IsPointer<typename T::ElementType>::value, bool>::Type
-operator==(const T& a, std::nullptr_t b) {
-    return js::detail::DefineComparisonOps<T>::get(a) == b;
-}
-
-template <typename T>
-typename mozilla::EnableIf<js::detail::DefineComparisonOps<T>::value &&
-                           mozilla::IsPointer<typename T::ElementType>::value, bool>::Type
-operator!=(const T& a, std::nullptr_t b) {
-    return !(a == b);
-}
-
 #undef DELETE_ASSIGNMENT_OPS
 
 #endif  /* js_RootingAPI_h */
diff -up firefox-55.0/js/src/gc/Barrier.h.1337988 firefox-55.0/js/src/gc/Barrier.h
--- firefox-55.0/js/src/gc/Barrier.h.1337988	2017-07-31 18:20:47.000000000 +0200
+++ firefox-55.0/js/src/gc/Barrier.h	2017-08-02 14:33:41.737715470 +0200
@@ -353,8 +353,8 @@ class WriteBarrieredBase : public Barrie
     explicit WriteBarrieredBase(const T& v) : BarrieredBase<T>(v) {}
 
   public:
-    using ElementType = T;
 
+    DECLARE_POINTER_COMPARISON_OPS(T);
     DECLARE_POINTER_CONSTREF_OPS(T);
 
     // Use this if the automatic coercion to T isn't working.
@@ -605,13 +605,14 @@ class ReadBarriered : public ReadBarrier
         return *this;
     }
 
-    const T& get() const {
-        if (InternalBarrierMethods<T>::isMarkable(this->value))
-            this->read();
+    const T get() const {
+        if (!InternalBarrierMethods<T>::isMarkable(this->value))
+            return JS::GCPolicy<T>::initial();
+        this->read();
         return this->value;
     }
 
-    const T& unbarrieredGet() const {
+    const T unbarrieredGet() const {
         return this->value;
     }
 
@@ -619,9 +620,9 @@ class ReadBarriered : public ReadBarrier
         return bool(this->value);
     }
 
-    operator const T&() const { return get(); }
+    operator const T() const { return get(); }
 
-    const T& operator->() const { return get(); }
+    const T operator->() const { return get(); }
 
     T* unsafeGet() { return &this->value; }
     T const* unsafeGet() const { return &this->value; }
@@ -948,35 +949,6 @@ typedef ReadBarriered<WasmTableObject*>
 
 typedef ReadBarriered<Value> ReadBarrieredValue;
 
-namespace detail {
-
-template <typename T>
-struct DefineComparisonOps<PreBarriered<T>> : mozilla::TrueType {
-    static const T& get(const PreBarriered<T>& v) { return v.get(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<GCPtr<T>> : mozilla::TrueType {
-    static const T& get(const GCPtr<T>& v) { return v.get(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<HeapPtr<T>> : mozilla::TrueType {
-    static const T& get(const HeapPtr<T>& v) { return v.get(); }
-};
-
-template <typename T>
-struct DefineComparisonOps<ReadBarriered<T>> : mozilla::TrueType {
-    static const T& get(const ReadBarriered<T>& v) { return v.unbarrieredGet(); }
-};
-
-template <>
-struct DefineComparisonOps<HeapSlot> : mozilla::TrueType {
-    static const Value& get(const HeapSlot& v) { return v.get(); }
-};
-
-} /* namespace detail */
-
 } /* namespace js */
 
 #endif /* gc_Barrier_h */
diff -up firefox-55.0/js/src/jsapi-tests/testGCHeapPostBarriers.cpp.1337988 firefox-55.0/js/src/jsapi-tests/testGCHeapPostBarriers.cpp
--- firefox-55.0/js/src/jsapi-tests/testGCHeapPostBarriers.cpp.1337988	2017-07-31 18:20:48.000000000 +0200
+++ firefox-55.0/js/src/jsapi-tests/testGCHeapPostBarriers.cpp	2017-08-02 15:23:03.544362400 +0200
@@ -5,7 +5,6 @@
  * 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/. */
 
-#include "mozilla/TypeTraits.h"
 #include "mozilla/UniquePtr.h"
 
 #include "js/RootingAPI.h"
@@ -178,117 +177,3 @@ TestHeapPostBarrierInitFailure()
 
     return true;
 }
-
-END_TEST(testGCHeapPostBarriers)
-
-BEGIN_TEST(testUnbarrieredEquality)
-{
-#ifdef JS_GC_ZEAL
-    AutoLeaveZeal nozeal(cx);
-#endif /* JS_GC_ZEAL */
-
-    // Use ArrayBuffers because they have finalizers, which allows using them
-    // in ObjectPtr without awkward conversations about nursery allocatability.
-    JS::RootedObject robj(cx, JS_NewArrayBuffer(cx, 20));
-    JS::RootedObject robj2(cx, JS_NewArrayBuffer(cx, 30));
-    cx->runtime()->gc.evictNursery(); // Need tenured objects
-
-    // Need some bare pointers to compare against.
-    JSObject* obj = robj;
-    JSObject* obj2 = robj2;
-    const JSObject* constobj = robj;
-    const JSObject* constobj2 = robj2;
-
-    // Make them gray. We will make sure they stay gray. (For most reads, the
-    // barrier will unmark gray.)
-    using namespace js::gc;
-    TenuredCell* cell = &obj->asTenured();
-    TenuredCell* cell2 = &obj2->asTenured();
-    cell->markIfUnmarked(GRAY);
-    cell2->markIfUnmarked(GRAY);
-    MOZ_ASSERT(cell->isMarked(GRAY));
-    MOZ_ASSERT(cell2->isMarked(GRAY));
-
-    {
-        JS::Heap<JSObject*> heap(obj);
-        JS::Heap<JSObject*> heap2(obj2);
-        CHECK(TestWrapper(obj, obj2, heap, heap2));
-        CHECK(TestWrapper(constobj, constobj2, heap, heap2));
-    }
-
-    {
-        JS::TenuredHeap<JSObject*> heap(obj);
-        JS::TenuredHeap<JSObject*> heap2(obj2);
-        CHECK(TestWrapper(obj, obj2, heap, heap2));
-        CHECK(TestWrapper(constobj, constobj2, heap, heap2));
-    }
-
-    {
-        JS::ObjectPtr objptr(obj);
-        JS::ObjectPtr objptr2(obj2);
-        CHECK(TestWrapper(obj, obj2, objptr, objptr2));
-        CHECK(TestWrapper(constobj, constobj2, objptr, objptr2));
-        objptr.finalize(cx);
-        objptr2.finalize(cx);
-    }
-
-    // Sanity check that the barriers normally mark things black.
-    {
-        JS::Heap<JSObject*> heap(obj);
-        JS::Heap<JSObject*> heap2(obj2);
-        heap.get();
-        heap2.get();
-        CHECK(cell->isMarked(BLACK));
-        CHECK(cell2->isMarked(BLACK));
-    }
-
-    return true;
-}
-
-template <typename ObjectT, typename WrapperT>
-bool
-TestWrapper(ObjectT obj, ObjectT obj2, WrapperT& wrapper, WrapperT& wrapper2)
-{
-    using namespace js::gc;
-
-    const TenuredCell& cell = obj->asTenured();
-    const TenuredCell& cell2 = obj2->asTenured();
-
-    int x = 0;
-
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-    x += obj == obj2;
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-    x += obj == wrapper2;
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-    x += wrapper == obj2;
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-    x += wrapper == wrapper2;
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-
-    CHECK(x == 0);
-
-    x += obj != obj2;
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-    x += obj != wrapper2;
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-    x += wrapper != obj2;
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-    x += wrapper != wrapper2;
-    CHECK(cell.isMarked(GRAY));
-    CHECK(cell2.isMarked(GRAY));
-
-    CHECK(x == 4);
-
-    return true;
-}
-
-END_TEST(testUnbarrieredEquality)
diff -up firefox-55.0/js/src/vm/SharedMem.h.1337988 firefox-55.0/js/src/vm/SharedMem.h
--- firefox-55.0/js/src/vm/SharedMem.h.1337988	2017-06-15 22:52:29.000000000 +0200
+++ firefox-55.0/js/src/vm/SharedMem.h	2017-08-02 14:33:41.737715470 +0200
@@ -12,8 +12,8 @@
 template<typename T>
 class SharedMem
 {
-    // static_assert(mozilla::IsPointer<T>::value,
-    //               "SharedMem encapsulates pointer types");
+    static_assert(mozilla::IsPointer<T>::value,
+                  "SharedMem encapsulates pointer types");
 
     enum Sharedness {
         IsUnshared,
diff -up firefox-55.0/js/xpconnect/src/XPCInlines.h.1337988 firefox-55.0/js/xpconnect/src/XPCInlines.h
--- firefox-55.0/js/xpconnect/src/XPCInlines.h.1337988	2017-07-31 18:20:46.000000000 +0200
+++ firefox-55.0/js/xpconnect/src/XPCInlines.h	2017-08-02 14:33:41.738715458 +0200
@@ -471,7 +471,7 @@ inline
 void XPCWrappedNativeTearOff::JSObjectMoved(JSObject* obj, const JSObject* old)
 {
     MOZ_ASSERT(!IsMarked());
-    MOZ_ASSERT(mJSObject == old);
+    MOZ_ASSERT(mJSObject.unbarrieredGetPtr() == old);
     mJSObject = obj;
 }
 
diff -up firefox-55.0/js/xpconnect/src/XPCWrappedNative.cpp.1337988 firefox-55.0/js/xpconnect/src/XPCWrappedNative.cpp
--- firefox-55.0/js/xpconnect/src/XPCWrappedNative.cpp.1337988	2017-08-02 14:33:41.738715458 +0200
+++ firefox-55.0/js/xpconnect/src/XPCWrappedNative.cpp	2017-08-02 15:25:43.749014973 +0200
@@ -874,7 +874,7 @@ void
 XPCWrappedNative::FlatJSObjectMoved(JSObject* obj, const JSObject* old)
 {
     JS::AutoAssertGCCallback inCallback;
-    MOZ_ASSERT(mFlatJSObject == old);
+    MOZ_ASSERT(mFlatJSObject.unbarrieredGetPtr() == old);
 
     nsWrapperCache* cache = nullptr;
     CallQueryInterface(mIdentity, &cache);
diff -up firefox-55.0/js/xpconnect/src/XPCWrappedNativeProto.cpp.1337988 firefox-55.0/js/xpconnect/src/XPCWrappedNativeProto.cpp
--- firefox-55.0/js/xpconnect/src/XPCWrappedNativeProto.cpp.1337988	2017-07-31 18:20:47.000000000 +0200
+++ firefox-55.0/js/xpconnect/src/XPCWrappedNativeProto.cpp	2017-08-02 15:24:15.153207106 +0200
@@ -101,7 +101,7 @@ XPCWrappedNativeProto::CallPostCreatePro
 void
 XPCWrappedNativeProto::JSProtoObjectFinalized(js::FreeOp* fop, JSObject* obj)
 {
-    MOZ_ASSERT(obj == mJSProtoObject, "huh?");
+    MOZ_ASSERT(obj == mJSProtoObject.unbarrieredGet(), "huh?");
 
 #ifdef DEBUG
     // Check that this object has already been swept from the map.
@@ -117,7 +117,7 @@ XPCWrappedNativeProto::JSProtoObjectFina
 void
 XPCWrappedNativeProto::JSProtoObjectMoved(JSObject* obj, const JSObject* old)
 {
-    MOZ_ASSERT(mJSProtoObject == old);
+    MOZ_ASSERT(mJSProtoObject.unbarrieredGet() == old);
     mJSProtoObject.init(obj); // Update without triggering barriers.
 }