Backed out changeset 0e35830f4a25 (bug 1679736) for rust failure CLOSED TREE

js/public/RootingAPI.h

@@ -925,22 +925,15 @@ enum class AutoGCRooterKind : uint8_t {
   Limit
 };
 
-namespace detail {
-// Dummy type to store root list entry pointers as. This code does not just use
-// the actual type, because then eg JSObject* and JSFunction* would be assumed
-// to never alias but they do (they are stored in the same list). Also, do not
-// use `void*` so that `Rooted<void*>` is a compile error.
-struct RootListEntry;
-}  // namespace detail
-
+// Our instantiations of Rooted<void*> and PersistentRooted<void*> require an
+// instantiation of MapTypeToRootKind.
 template <>
-struct MapTypeToRootKind<detail::RootListEntry*> {
+struct MapTypeToRootKind<void*> {
   static const RootKind kind = RootKind::Traceable;
 };
 
 using RootedListHeads =
-    mozilla::EnumeratedArray<RootKind, RootKind::Limit,
-                             Rooted<detail::RootListEntry*>*>;
+    mozilla::EnumeratedArray<RootKind, RootKind::Limit, Rooted<void*>*>;
 
 using AutoRooterListHeads =
     mozilla::EnumeratedArray<AutoGCRooterKind, AutoGCRooterKind::Limit,
@@ -1080,7 +1073,7 @@ class MOZ_RAII Rooted : public js::RootedBase<T, Rooted<T>> {
   inline void registerWithRootLists(RootedListHeads& roots) {
     this->stack = &roots[JS::MapTypeToRootKind<T>::kind];
     this->prev = *stack;
-    *stack = reinterpret_cast<Rooted<detail::RootListEntry*>*>(this);
+    *stack = reinterpret_cast<Rooted<void*>*>(this);
   }
 
   inline RootedListHeads& rootLists(RootingContext* cx) {
@@ -1130,8 +1123,7 @@ class MOZ_RAII Rooted : public js::RootedBase<T, Rooted<T>> {
   }
 
   ~Rooted() {
-    MOZ_ASSERT(*stack ==
-               reinterpret_cast<Rooted<detail::RootListEntry*>*>(this));
+    MOZ_ASSERT(*stack == reinterpret_cast<Rooted<void*>*>(this));
     *stack = prev;
   }
 
@@ -1163,12 +1155,12 @@ class MOZ_RAII Rooted : public js::RootedBase<T, Rooted<T>> {
 
  private:
   /*
-   * These need to be templated on RootListEntry* to avoid aliasing issues
-   * between, for example, Rooted<JSObject*> and Rooted<JSFunction*>, which use
-   * the same stack head pointer for different classes.
+   * These need to be templated on void* to avoid aliasing issues between, for
+   * example, Rooted<JSObject> and Rooted<JSFunction>, which use the same
+   * stack head pointer for different classes.
    */
-  Rooted<detail::RootListEntry*>** stack;
-  Rooted<detail::RootListEntry*>* prev;
+  Rooted<void*>** stack;
+  Rooted<void*>* prev;
 
   Ptr ptr;
 
@@ -1297,13 +1289,11 @@ inline MutableHandle<T>::MutableHandle(PersistentRooted<T>* root) {
   ptr = root->address();
 }
 
-JS_PUBLIC_API void AddPersistentRoot(
-    RootingContext* cx, RootKind kind,
-    PersistentRooted<detail::RootListEntry*>* root);
+JS_PUBLIC_API void AddPersistentRoot(RootingContext* cx, RootKind kind,
+                                     PersistentRooted<void*>* root);
 
-JS_PUBLIC_API void AddPersistentRoot(
-    JSRuntime* rt, RootKind kind,
-    PersistentRooted<detail::RootListEntry*>* root);
+JS_PUBLIC_API void AddPersistentRoot(JSRuntime* rt, RootKind kind,
+                                     PersistentRooted<void*>* root);
 
 /**
  * A copyable, assignable global GC root type with arbitrary lifetime, an
@@ -1352,17 +1342,15 @@ class PersistentRooted
   void registerWithRootLists(RootingContext* cx) {
     MOZ_ASSERT(!initialized());
     JS::RootKind kind = JS::MapTypeToRootKind<T>::kind;
-    AddPersistentRoot(
-        cx, kind,
-        reinterpret_cast<JS::PersistentRooted<detail::RootListEntry*>*>(this));
+    AddPersistentRoot(cx, kind,
+                      reinterpret_cast<JS::PersistentRooted<void*>*>(this));
   }
 
   void registerWithRootLists(JSRuntime* rt) {
     MOZ_ASSERT(!initialized());
     JS::RootKind kind = JS::MapTypeToRootKind<T>::kind;
-    AddPersistentRoot(
-        rt, kind,
-        reinterpret_cast<JS::PersistentRooted<detail::RootListEntry*>*>(this));
+    AddPersistentRoot(rt, kind,
+                      reinterpret_cast<JS::PersistentRooted<void*>*>(this));
   }
 
  public:

js/src/gc/RootMarking.cpp

@@ -75,9 +75,9 @@ inline void JS::PersistentRooted<T>::trace(JSTracer* trc, const char* name) {
 }
 
 template <typename T>
-static inline void TraceExactStackRootList(
-    JSTracer* trc, JS::Rooted<JS::detail::RootListEntry*>* listHead,
-    const char* name) {
+static inline void TraceExactStackRootList(JSTracer* trc,
+                                           JS::Rooted<void*>* listHead,
+                                           const char* name) {
   auto* typedList = reinterpret_cast<JS::Rooted<T>*>(listHead);
   for (JS::Rooted<T>* root = typedList; root; root = root->previous()) {
     root->trace(trc, name);
@@ -112,8 +112,7 @@ static void TraceExactStackRoots(JSContext* cx, JSTracer* trc) {
 
 template <typename T>
 static inline void TracePersistentRootedList(
-    JSTracer* trc,
-    LinkedList<PersistentRooted<JS::detail::RootListEntry*>>& list,
+    JSTracer* trc, LinkedList<PersistentRooted<void*>>& list,
     const char* name) {
   auto& typedList = reinterpret_cast<LinkedList<PersistentRooted<T>>&>(list);
   for (PersistentRooted<T>* root : typedList) {
@@ -145,7 +144,7 @@ static void TracePersistentRooted(JSRuntime* rt, JSTracer* trc) {
 
 template <typename T>
 static void FinishPersistentRootedChain(
-    LinkedList<PersistentRooted<JS::detail::RootListEntry*>>& listArg) {
+    LinkedList<PersistentRooted<void*>>& listArg) {
   auto& list = reinterpret_cast<LinkedList<PersistentRooted<T>>&>(listArg);
   while (!list.isEmpty()) {
     list.getFirst()->reset();
@@ -635,15 +634,13 @@ void GCRuntime::resetBufferedGrayRoots() {
   }
 }
 
-JS_PUBLIC_API void JS::AddPersistentRoot(
-    JS::RootingContext* cx, RootKind kind,
-    PersistentRooted<JS::detail::RootListEntry*>* root) {
+JS_PUBLIC_API void JS::AddPersistentRoot(JS::RootingContext* cx, RootKind kind,
+                                         PersistentRooted<void*>* root) {
   static_cast<JSContext*>(cx)->runtime()->heapRoots.ref()[kind].insertBack(
       root);
 }
 
-JS_PUBLIC_API void JS::AddPersistentRoot(
-    JSRuntime* rt, RootKind kind,
-    PersistentRooted<JS::detail::RootListEntry*>* root) {
+JS_PUBLIC_API void JS::AddPersistentRoot(JSRuntime* rt, RootKind kind,
+                                         PersistentRooted<void*>* root) {
   rt->heapRoots.ref()[kind].insertBack(root);
 }

js/src/vm/Runtime.h

@@ -394,7 +394,7 @@ struct JSRuntime {
   // Heap GC roots for PersistentRooted pointers.
   js::MainThreadData<mozilla::EnumeratedArray<
       JS::RootKind, JS::RootKind::Limit,
-      mozilla::LinkedList<JS::PersistentRooted<JS::detail::RootListEntry*>>>>
+      mozilla::LinkedList<JS::PersistentRooted<void*>>>>
       heapRoots;
 
   void tracePersistentRoots(JSTracer* trc);