diff --git a/docshell/base/timeline/AutoGlobalTimelineMarker.h b/docshell/base/timeline/AutoGlobalTimelineMarker.h
index de6ea15c0f5..22983ebefe7 100644
--- a/docshell/base/timeline/AutoGlobalTimelineMarker.h
+++ b/docshell/base/timeline/AutoGlobalTimelineMarker.h
@@ -29,7 +29,7 @@ namespace mozilla {
 //       cc->Collect();
 //       ...
 //     }
-class MOZ_STACK_CLASS AutoGlobalTimelineMarker
+class MOZ_RAII AutoGlobalTimelineMarker
 {
   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
 
diff --git a/docshell/base/timeline/AutoTimelineMarker.h b/docshell/base/timeline/AutoTimelineMarker.h
index b024660971f..7f010736080 100644
--- a/docshell/base/timeline/AutoTimelineMarker.h
+++ b/docshell/base/timeline/AutoTimelineMarker.h
@@ -28,7 +28,7 @@ namespace mozilla {
 //       nsresult rv = ParseTheCSSFile(mFile);
 //       ...
 //     }
-class MOZ_STACK_CLASS AutoTimelineMarker
+class MOZ_RAII AutoTimelineMarker
 {
   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
 
diff --git a/dom/base/ScriptSettings.h b/dom/base/ScriptSettings.h
index 573d7869b9d..7b04425223b 100644
--- a/dom/base/ScriptSettings.h
+++ b/dom/base/ScriptSettings.h
@@ -412,7 +412,7 @@ private:
  * passed as a parameter. AutoJSContext will take care of finding the most
  * appropriate JS context and release it when leaving the stack.
  */
-class MOZ_STACK_CLASS AutoJSContext {
+class MOZ_RAII AutoJSContext {
 public:
   explicit AutoJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
   operator JSContext*() const;
@@ -434,7 +434,7 @@ protected:
  * Use ThreadsafeAutoJSContext when you want an AutoJSContext but might be
  * running on a worker thread.
  */
-class MOZ_STACK_CLASS ThreadsafeAutoJSContext {
+class MOZ_RAII ThreadsafeAutoJSContext {
 public:
   explicit ThreadsafeAutoJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
   operator JSContext*() const;
@@ -452,7 +452,7 @@ private:
  *
  * Note - This is deprecated. Please use AutoJSAPI instead.
  */
-class MOZ_STACK_CLASS AutoSafeJSContext : public AutoJSContext {
+class MOZ_RAII AutoSafeJSContext : public AutoJSContext {
 public:
   explicit AutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
 private:
@@ -462,7 +462,7 @@ private:
 /**
  * Like AutoSafeJSContext but can be used safely on worker threads.
  */
-class MOZ_STACK_CLASS ThreadsafeAutoSafeJSContext {
+class MOZ_RAII ThreadsafeAutoSafeJSContext {
 public:
   explicit ThreadsafeAutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
   operator JSContext*() const;
diff --git a/dom/base/nsContentUtils.h b/dom/base/nsContentUtils.h
index 9ec4b62f772..bfe67f45645 100644
--- a/dom/base/nsContentUtils.h
+++ b/dom/base/nsContentUtils.h
@@ -2651,7 +2651,7 @@ private:
 #endif
 };
 
-class MOZ_STACK_CLASS nsAutoScriptBlocker {
+class MOZ_RAII nsAutoScriptBlocker {
 public:
   explicit nsAutoScriptBlocker(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM) {
     MOZ_GUARD_OBJECT_NOTIFIER_INIT;
diff --git a/dom/base/nsFrameLoader.cpp b/dom/base/nsFrameLoader.cpp
index 5e41edc2a08..de1d249a4ec 100644
--- a/dom/base/nsFrameLoader.cpp
+++ b/dom/base/nsFrameLoader.cpp
@@ -634,7 +634,7 @@ AllDescendantsOfType(nsIDocShellTreeItem* aParentItem, int32_t aType)
  * A class that automatically sets mInShow to false when it goes
  * out of scope.
  */
-class MOZ_STACK_CLASS AutoResetInShow {
+class MOZ_RAII AutoResetInShow {
   private:
     nsFrameLoader* mFrameLoader;
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
@@ -989,7 +989,7 @@ nsFrameLoader::SwapWithOtherRemoteLoader(nsFrameLoader* aOther,
   return NS_OK;
 }
 
-class MOZ_STACK_CLASS AutoResetInFrameSwap final
+class MOZ_RAII AutoResetInFrameSwap final
 {
 public:
   AutoResetInFrameSwap(nsFrameLoader* aThisFrameLoader,
diff --git a/dom/bindings/BindingUtils.h b/dom/bindings/BindingUtils.h
index f822d9a6230..57adbb097f4 100644
--- a/dom/bindings/BindingUtils.h
+++ b/dom/bindings/BindingUtils.h
@@ -2266,7 +2266,7 @@ void DoTraceSequence(JSTracer* trc, InfallibleTArray<T>& seq)
 
 // Rooter class for sequences; this is what we mostly use in the codegen
 template<typename T>
-class MOZ_STACK_CLASS SequenceRooter : private JS::CustomAutoRooter
+class MOZ_RAII SequenceRooter : private JS::CustomAutoRooter
 {
 public:
   SequenceRooter(JSContext *aCx, FallibleTArray<T>* aSequence
@@ -2325,7 +2325,7 @@ public:
 
 // Rooter class for MozMap; this is what we mostly use in the codegen.
 template<typename T>
-class MOZ_STACK_CLASS MozMapRooter : private JS::CustomAutoRooter
+class MOZ_RAII MozMapRooter : private JS::CustomAutoRooter
 {
 public:
   MozMapRooter(JSContext *aCx, MozMap<T>* aMozMap
@@ -2371,8 +2371,8 @@ private:
 };
 
 template<typename T>
-class MOZ_STACK_CLASS RootedUnion : public T,
-                                    private JS::CustomAutoRooter
+class MOZ_RAII RootedUnion : public T,
+                             private JS::CustomAutoRooter
 {
 public:
   explicit RootedUnion(JSContext* cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM) :
diff --git a/dom/bindings/RootedDictionary.h b/dom/bindings/RootedDictionary.h
index a8f2a79762f..73a6c730a10 100644
--- a/dom/bindings/RootedDictionary.h
+++ b/dom/bindings/RootedDictionary.h
@@ -15,7 +15,7 @@ namespace mozilla {
 namespace dom {
 
 template<typename T>
-class MOZ_STACK_CLASS RootedDictionary : public T,
+class MOZ_RAII RootedDictionary : public T,
                                          private JS::CustomAutoRooter
 {
 public:
@@ -32,7 +32,7 @@ public:
 };
 
 template<typename T>
-class MOZ_STACK_CLASS NullableRootedDictionary : public Nullable<T>,
+class MOZ_RAII NullableRootedDictionary : public Nullable<T>,
                                                  private JS::CustomAutoRooter
 {
 public:
diff --git a/dom/bindings/TypedArray.h b/dom/bindings/TypedArray.h
index d4f829f7590..c8c8279e4a3 100644
--- a/dom/bindings/TypedArray.h
+++ b/dom/bindings/TypedArray.h
@@ -327,7 +327,7 @@ class TypedArrayCreator
 
 // A class for rooting an existing TypedArray struct
 template<typename ArrayType>
-class MOZ_STACK_CLASS TypedArrayRooter : private JS::CustomAutoRooter
+class MOZ_RAII TypedArrayRooter : private JS::CustomAutoRooter
 {
 public:
   TypedArrayRooter(JSContext* cx,
@@ -349,7 +349,7 @@ private:
 // And a specialization for dealing with nullable typed arrays
 template<typename Inner> struct Nullable;
 template<typename ArrayType>
-class MOZ_STACK_CLASS TypedArrayRooter<Nullable<ArrayType> > :
+class MOZ_RAII TypedArrayRooter<Nullable<ArrayType> > :
     private JS::CustomAutoRooter
 {
 public:
@@ -373,8 +373,8 @@ private:
 
 // Class for easily setting up a rooted typed array object on the stack
 template<typename ArrayType>
-class MOZ_STACK_CLASS RootedTypedArray : public ArrayType,
-                                         private TypedArrayRooter<ArrayType>
+class MOZ_RAII RootedTypedArray : public ArrayType,
+                                  private TypedArrayRooter<ArrayType>
 {
 public:
   explicit RootedTypedArray(JSContext* cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM) :
diff --git a/dom/media/MediaResource.h b/dom/media/MediaResource.h
index 041144f8d61..160404e3337 100644
--- a/dom/media/MediaResource.h
+++ b/dom/media/MediaResource.h
@@ -794,7 +794,7 @@ protected:
  * us.
  */
 template<class T>
-class MOZ_STACK_CLASS AutoPinned {
+class MOZ_RAII AutoPinned {
  public:
   explicit AutoPinned(T* aResource MOZ_GUARD_OBJECT_NOTIFIER_PARAM) : mResource(aResource) {
     MOZ_GUARD_OBJECT_NOTIFIER_INIT;
diff --git a/dom/plugins/ipc/PluginModuleParent.cpp b/dom/plugins/ipc/PluginModuleParent.cpp
index e47bc11fa3d..178b9f0c58f 100755
--- a/dom/plugins/ipc/PluginModuleParent.cpp
+++ b/dom/plugins/ipc/PluginModuleParent.cpp
@@ -306,7 +306,7 @@ public:
         return sIsLoadModuleOnStack;
     }
 
-    class MOZ_STACK_CLASS NotifyLoadingModule
+    class MOZ_RAII NotifyLoadingModule
     {
     public:
         explicit NotifyLoadingModule(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM)
diff --git a/dom/svg/DOMSVGLength.cpp b/dom/svg/DOMSVGLength.cpp
index 3e1f8aca618..f5940a50645 100644
--- a/dom/svg/DOMSVGLength.cpp
+++ b/dom/svg/DOMSVGLength.cpp
@@ -66,7 +66,7 @@ NS_INTERFACE_MAP_END
 // Helper class: AutoChangeLengthNotifier
 // Stack-based helper class to pair calls to WillChangeLengthList and
 // DidChangeLengthList.
-class MOZ_STACK_CLASS AutoChangeLengthNotifier
+class MOZ_RAII AutoChangeLengthNotifier
 {
 public:
   explicit AutoChangeLengthNotifier(DOMSVGLength* aLength MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGLengthList.cpp b/dom/svg/DOMSVGLengthList.cpp
index 1788d7a3980..7d341d130ef 100644
--- a/dom/svg/DOMSVGLengthList.cpp
+++ b/dom/svg/DOMSVGLengthList.cpp
@@ -79,7 +79,7 @@ DOMSVGLengthList::WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto)
 // Helper class: AutoChangeLengthListNotifier
 // Stack-based helper class to pair calls to WillChangeLengthList and
 // DidChangeLengthList.
-class MOZ_STACK_CLASS AutoChangeLengthListNotifier
+class MOZ_RAII AutoChangeLengthListNotifier
 {
 public:
   explicit AutoChangeLengthListNotifier(DOMSVGLengthList* aLengthList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGNumber.cpp b/dom/svg/DOMSVGNumber.cpp
index d75fa96f6b1..d9a014a0ca1 100644
--- a/dom/svg/DOMSVGNumber.cpp
+++ b/dom/svg/DOMSVGNumber.cpp
@@ -53,7 +53,7 @@ NS_INTERFACE_MAP_END
 // Helper class: AutoChangeNumberNotifier
 // Stack-based helper class to pair calls to WillChangeNumberList and
 // DidChangeNumberList.
-class MOZ_STACK_CLASS AutoChangeNumberNotifier
+class MOZ_RAII AutoChangeNumberNotifier
 {
 public:
   explicit AutoChangeNumberNotifier(DOMSVGNumber* aNumber MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGNumberList.cpp b/dom/svg/DOMSVGNumberList.cpp
index 9df233c85b9..6aad17c2064 100644
--- a/dom/svg/DOMSVGNumberList.cpp
+++ b/dom/svg/DOMSVGNumberList.cpp
@@ -80,7 +80,7 @@ DOMSVGNumberList::WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto)
 // Helper class: AutoChangeNumberListNotifier
 // Stack-based helper class to pair calls to WillChangeNumberList and
 // DidChangeNumberList.
-class MOZ_STACK_CLASS AutoChangeNumberListNotifier
+class MOZ_RAII AutoChangeNumberListNotifier
 {
 public:
   explicit AutoChangeNumberListNotifier(DOMSVGNumberList* aNumberList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGPathSeg.cpp b/dom/svg/DOMSVGPathSeg.cpp
index 1b2f19e564c..521420e8f46 100644
--- a/dom/svg/DOMSVGPathSeg.cpp
+++ b/dom/svg/DOMSVGPathSeg.cpp
@@ -45,7 +45,7 @@ NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(DOMSVGPathSeg, Release)
 // Helper class: AutoChangePathSegNotifier
 // Stack-based helper class to pair calls to WillChangePathSegList
 // and DidChangePathSegList.
-class MOZ_STACK_CLASS AutoChangePathSegNotifier
+class MOZ_RAII AutoChangePathSegNotifier
 {
 public:
   explicit AutoChangePathSegNotifier(DOMSVGPathSeg* aPathSeg MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGPathSegList.cpp b/dom/svg/DOMSVGPathSegList.cpp
index 0a0c28f730b..78fa31c6054 100644
--- a/dom/svg/DOMSVGPathSegList.cpp
+++ b/dom/svg/DOMSVGPathSegList.cpp
@@ -55,7 +55,7 @@ NS_INTERFACE_MAP_END
 // Helper class: AutoChangePathSegListNotifier
 // Stack-based helper class to pair calls to WillChangePathSegList and
 // DidChangePathSegList.
-class MOZ_STACK_CLASS AutoChangePathSegListNotifier
+class MOZ_RAII AutoChangePathSegListNotifier
 {
 public:
   explicit AutoChangePathSegListNotifier(DOMSVGPathSegList* aPathSegList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGPoint.cpp b/dom/svg/DOMSVGPoint.cpp
index 20da6ae04b5..05d5754906c 100644
--- a/dom/svg/DOMSVGPoint.cpp
+++ b/dom/svg/DOMSVGPoint.cpp
@@ -23,7 +23,7 @@ namespace mozilla {
 // Helper class: AutoChangePointNotifier
 // Stack-based helper class to pair calls to WillChangePointList and
 // DidChangePointList.
-class MOZ_STACK_CLASS AutoChangePointNotifier
+class MOZ_RAII AutoChangePointNotifier
 {
 public:
   explicit AutoChangePointNotifier(DOMSVGPoint* aPoint MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGPointList.cpp b/dom/svg/DOMSVGPointList.cpp
index 9c52471e63c..31315c028ec 100644
--- a/dom/svg/DOMSVGPointList.cpp
+++ b/dom/svg/DOMSVGPointList.cpp
@@ -73,7 +73,7 @@ NS_INTERFACE_MAP_END
 // Helper class: AutoChangePointListNotifier
 // Stack-based helper class to pair calls to WillChangePointList and
 // DidChangePointList.
-class MOZ_STACK_CLASS AutoChangePointListNotifier
+class MOZ_RAII AutoChangePointListNotifier
 {
 public:
   explicit AutoChangePointListNotifier(DOMSVGPointList* aPointList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGStringList.cpp b/dom/svg/DOMSVGStringList.cpp
index 81004993d9b..35e54213b0c 100644
--- a/dom/svg/DOMSVGStringList.cpp
+++ b/dom/svg/DOMSVGStringList.cpp
@@ -43,7 +43,7 @@ NS_INTERFACE_MAP_END
 // Helper class: AutoChangeStringListNotifier
 // Stack-based helper class to pair calls to WillChangeStringListList and
 // DidChangeStringListList.
-class MOZ_STACK_CLASS AutoChangeStringListNotifier
+class MOZ_RAII AutoChangeStringListNotifier
 {
 public:
   explicit AutoChangeStringListNotifier(DOMSVGStringList* aStringList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/DOMSVGTransformList.cpp b/dom/svg/DOMSVGTransformList.cpp
index 87930c994db..b5554262d56 100644
--- a/dom/svg/DOMSVGTransformList.cpp
+++ b/dom/svg/DOMSVGTransformList.cpp
@@ -81,7 +81,7 @@ DOMSVGTransformList::WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto
 // Helper class: AutoChangeTransformListNotifier
 // Stack-based helper class to pair calls to WillChangeTransformList and
 // DidChangeTransformList.
-class MOZ_STACK_CLASS AutoChangeTransformListNotifier
+class MOZ_RAII AutoChangeTransformListNotifier
 {
 public:
   explicit AutoChangeTransformListNotifier(DOMSVGTransformList* aTransformList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/svg/SVGSVGElement.h b/dom/svg/SVGSVGElement.h
index f331e91e4c4..fb75752b0bb 100644
--- a/dom/svg/SVGSVGElement.h
+++ b/dom/svg/SVGSVGElement.h
@@ -407,7 +407,7 @@ private:
 
 // Helper class to automatically manage temporary changes to an SVG document's
 // state for rendering purposes.
-class MOZ_STACK_CLASS AutoSVGRenderingState
+class MOZ_RAII AutoSVGRenderingState
 {
 public:
   AutoSVGRenderingState(const Maybe<SVGImageContext>& aSVGContext,
diff --git a/dom/svg/SVGTransform.cpp b/dom/svg/SVGTransform.cpp
index daa09644b14..e6574a86cac 100644
--- a/dom/svg/SVGTransform.cpp
+++ b/dom/svg/SVGTransform.cpp
@@ -71,7 +71,7 @@ SVGTransform::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 // Helper class: AutoChangeTransformNotifier
 // Stack-based helper class to pair calls to WillChangeTransformList
 // and DidChangeTransformList.
-class MOZ_STACK_CLASS AutoChangeTransformNotifier
+class MOZ_RAII AutoChangeTransformNotifier
 {
 public:
   explicit AutoChangeTransformNotifier(SVGTransform* aTransform MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/dom/workers/XMLHttpRequest.cpp b/dom/workers/XMLHttpRequest.cpp
index 291eeeff28f..6bd41f337c3 100644
--- a/dom/workers/XMLHttpRequest.cpp
+++ b/dom/workers/XMLHttpRequest.cpp
@@ -543,7 +543,7 @@ class EventRunnable final : public MainThreadProxyRunnable
   nsresult mResponseResult;
 
 public:
-  class StateDataAutoRooter : private JS::CustomAutoRooter
+  class MOZ_RAII StateDataAutoRooter : private JS::CustomAutoRooter
   {
     XMLHttpRequest::StateData* mStateData;
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
diff --git a/editor/libeditor/nsEditorUtils.h b/editor/libeditor/nsEditorUtils.h
index 0d8248174ef..ab2552f9ea9 100644
--- a/editor/libeditor/nsEditorUtils.h
+++ b/editor/libeditor/nsEditorUtils.h
@@ -31,7 +31,7 @@ class Selection;
  * stack based helper class for batching a collection of txns inside a
  * placeholder txn.
  */
-class MOZ_STACK_CLASS nsAutoPlaceHolderBatch
+class MOZ_RAII nsAutoPlaceHolderBatch
 {
   private:
     nsCOMPtr<nsIEditor> mEd;
@@ -58,7 +58,7 @@ class MOZ_STACK_CLASS nsAutoPlaceHolderBatch
  * Note: I changed this to use placeholder batching so that we get
  * proper selection save/restore across undo/redo.
  */
-class MOZ_STACK_CLASS nsAutoEditBatch : public nsAutoPlaceHolderBatch
+class MOZ_RAII nsAutoEditBatch : public nsAutoPlaceHolderBatch
 {
   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
   public:
@@ -74,7 +74,7 @@ class MOZ_STACK_CLASS nsAutoEditBatch : public nsAutoPlaceHolderBatch
  * stack based helper class for saving/restoring selection.  Note that this
  * assumes that the nodes involved are still around afterwards!
  */
-class MOZ_STACK_CLASS nsAutoSelectionReset
+class MOZ_RAII nsAutoSelectionReset
 {
   private:
     /** ref-counted reference to the selection that we are supposed to restore */
@@ -96,7 +96,7 @@ class MOZ_STACK_CLASS nsAutoSelectionReset
 /***************************************************************************
  * stack based helper class for StartOperation()/EndOperation() sandwich
  */
-class MOZ_STACK_CLASS nsAutoRules
+class MOZ_RAII nsAutoRules
 {
   public:
 
@@ -131,7 +131,7 @@ class MOZ_STACK_CLASS nsAutoRules
  * stack based helper class for turning off active selection adjustment
  * by low level transactions
  */
-class MOZ_STACK_CLASS nsAutoTxnsConserveSelection
+class MOZ_RAII nsAutoTxnsConserveSelection
 {
   public:
 
@@ -163,7 +163,7 @@ class MOZ_STACK_CLASS nsAutoTxnsConserveSelection
 /***************************************************************************
  * stack based helper class for batching reflow and paint requests.
  */
-class MOZ_STACK_CLASS nsAutoUpdateViewBatch
+class MOZ_RAII nsAutoUpdateViewBatch
 {
   public:
 
@@ -197,7 +197,7 @@ class nsBoolDomIterFunctor
     virtual bool operator()(nsINode* aNode) const = 0;
 };
 
-class MOZ_STACK_CLASS nsDOMIterator
+class MOZ_RAII nsDOMIterator
 {
   public:
     explicit nsDOMIterator(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
@@ -214,7 +214,7 @@ class MOZ_STACK_CLASS nsDOMIterator
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-class MOZ_STACK_CLASS nsDOMSubtreeIterator : public nsDOMIterator
+class MOZ_RAII nsDOMSubtreeIterator : public nsDOMIterator
 {
   public:
     explicit nsDOMSubtreeIterator(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
diff --git a/ipc/glue/MessageChannel.cpp b/ipc/glue/MessageChannel.cpp
index 1b50a5cefa2..9341ba5cdef 100644
--- a/ipc/glue/MessageChannel.cpp
+++ b/ipc/glue/MessageChannel.cpp
@@ -277,7 +277,7 @@ private:
 
 namespace {
 
-class MOZ_STACK_CLASS MaybeScriptBlocker {
+class MOZ_RAII MaybeScriptBlocker {
 public:
     explicit MaybeScriptBlocker(MessageChannel *aChannel, bool aBlock
                                 MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/ipc/glue/Neutering.h b/ipc/glue/Neutering.h
index ea1a2bf5e9a..70657c53c19 100644
--- a/ipc/glue/Neutering.h
+++ b/ipc/glue/Neutering.h
@@ -23,7 +23,7 @@ namespace ipc {
  * current thread will be neutered. It is safe to nest multiple instances of
  * this class.
  */
-class MOZ_STACK_CLASS NeuteredWindowRegion
+class MOZ_RAII NeuteredWindowRegion
 {
 public:
   explicit NeuteredWindowRegion(bool aDoNeuter MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
@@ -46,7 +46,7 @@ private:
  * disabling neutering for the remainder of its enclosing block.
  * @see NeuteredWindowRegion
  */
-class MOZ_STACK_CLASS DeneuteredWindowRegion
+class MOZ_RAII DeneuteredWindowRegion
 {
 public:
   DeneuteredWindowRegion(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
diff --git a/js/ipc/CPOWTimer.h b/js/ipc/CPOWTimer.h
index 898806c64ab..91dc66fd7fc 100644
--- a/js/ipc/CPOWTimer.h
+++ b/js/ipc/CPOWTimer.h
@@ -20,7 +20,7 @@
  * This stopwatch is active iff JSRuntime::stopwatch.isActive is set.
  * Upon destruction, update JSRuntime::stopwatch.data.totalCPOWTime.
  */
-class MOZ_STACK_CLASS CPOWTimer final {
+class MOZ_RAII CPOWTimer final {
   public:
     explicit inline CPOWTimer(JSContext* cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
     ~CPOWTimer();
diff --git a/js/public/RootingAPI.h b/js/public/RootingAPI.h
index 8995115d873..705082f8755 100644
--- a/js/public/RootingAPI.h
+++ b/js/public/RootingAPI.h
@@ -654,7 +654,7 @@ namespace JS {
  * specialization, define a RootedBase<T> specialization containing them.
  */
 template <typename T>
-class MOZ_STACK_CLASS Rooted : public js::RootedBase<T>
+class MOZ_RAII Rooted : public js::RootedBase<T>
 {
     static_assert(!mozilla::IsConvertible<T, Traceable*>::value,
                   "Rooted takes pointer or Traceable types but not Traceable* type");
@@ -777,7 +777,7 @@ class HandleBase<JSObject*>
 
 /* Interface substitute for Rooted<T> which does not root the variable's memory. */
 template <typename T>
-class FakeRooted : public RootedBase<T>
+class MOZ_RAII FakeRooted : public RootedBase<T>
 {
   public:
     template <typename CX>
diff --git a/js/src/ds/LifoAlloc.h b/js/src/ds/LifoAlloc.h
index 80e0ee503f8..14a97c93a40 100644
--- a/js/src/ds/LifoAlloc.h
+++ b/js/src/ds/LifoAlloc.h
@@ -482,7 +482,7 @@ class LifoAlloc
     };
 };
 
-class LifoAllocScope
+class MOZ_NON_TEMPORARY_CLASS LifoAllocScope
 {
     LifoAlloc*      lifoAlloc;
     LifoAlloc::Mark mark;
diff --git a/js/src/gc/GCInternals.h b/js/src/gc/GCInternals.h
index 0c07eace019..f1913851380 100644
--- a/js/src/gc/GCInternals.h
+++ b/js/src/gc/GCInternals.h
@@ -92,7 +92,7 @@ IsIncrementalGCSafe(JSRuntime* rt);
 
 #ifdef JS_GC_ZEAL
 
-class AutoStopVerifyingBarriers
+class MOZ_RAII AutoStopVerifyingBarriers
 {
     GCRuntime* gc;
     bool restartPreVerifier;
@@ -152,7 +152,7 @@ struct MovingTracer : JS::CallbackTracer
 #endif
 };
 
-class AutoMaybeStartBackgroundAllocation
+class MOZ_RAII AutoMaybeStartBackgroundAllocation
 {
   private:
     JSRuntime* runtime;
@@ -176,7 +176,7 @@ class AutoMaybeStartBackgroundAllocation
 };
 
 // In debug builds, set/unset the GC sweeping flag for the current thread.
-struct AutoSetThreadIsSweeping
+struct MOZ_RAII AutoSetThreadIsSweeping
 {
 #ifdef DEBUG
     explicit AutoSetThreadIsSweeping(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM)
diff --git a/js/src/gc/Statistics.h b/js/src/gc/Statistics.h
index 5e6c1b143e7..5e0f7f6ed15 100644
--- a/js/src/gc/Statistics.h
+++ b/js/src/gc/Statistics.h
@@ -331,7 +331,7 @@ struct Statistics
     double computeMMU(int64_t resolution) const;
 };
 
-struct AutoGCSlice
+struct MOZ_RAII AutoGCSlice
 {
     AutoGCSlice(Statistics& stats, const ZoneGCStats& zoneStats, JSGCInvocationKind gckind,
                 SliceBudget budget, JS::gcreason::Reason reason
@@ -347,7 +347,7 @@ struct AutoGCSlice
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-struct AutoPhase
+struct MOZ_RAII AutoPhase
 {
     AutoPhase(Statistics& stats, Phase phase
               MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
@@ -391,7 +391,7 @@ struct AutoPhase
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-struct AutoSCC
+struct MOZ_RAII AutoSCC
 {
     AutoSCC(Statistics& stats, unsigned scc
             MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/js/src/jit/Ion.cpp b/js/src/jit/Ion.cpp
index 2408bd293aa..69a0e2976e1 100644
--- a/js/src/jit/Ion.cpp
+++ b/js/src/jit/Ion.cpp
@@ -518,7 +518,7 @@ FinishAllOffThreadCompilations(JSCompartment* comp)
     }
 }
 
-class AutoLazyLinkExitFrame
+class MOZ_RAII AutoLazyLinkExitFrame
 {
     JitActivation* jitActivation_;
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
diff --git a/js/src/jit/JitSpewer.cpp b/js/src/jit/JitSpewer.cpp
index afce391b0a8..3a9b53ebed7 100644
--- a/js/src/jit/JitSpewer.cpp
+++ b/js/src/jit/JitSpewer.cpp
@@ -75,7 +75,7 @@ class IonSpewer
     }
 };
 
-class AutoLockIonSpewerOutput
+class MOZ_RAII AutoLockIonSpewerOutput
 {
   private:
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 7faf2859fd0..c4a1c980342 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -67,7 +67,7 @@ class JS_PUBLIC_API(AutoCheckRequestDepth)
 
 /* AutoValueArray roots an internal fixed-size array of Values. */
 template <size_t N>
-class AutoValueArray : public AutoGCRooter
+class MOZ_RAII AutoValueArray : public AutoGCRooter
 {
     const size_t length_;
     Value elements_[N];
@@ -99,7 +99,7 @@ class AutoValueArray : public AutoGCRooter
 };
 
 template<class T>
-class AutoVectorRooterBase : protected AutoGCRooter
+class MOZ_RAII AutoVectorRooterBase : protected AutoGCRooter
 {
     typedef js::Vector<T, 8> VectorImpl;
     VectorImpl vector;
@@ -196,7 +196,7 @@ class AutoVectorRooterBase : protected AutoGCRooter
 };
 
 template <typename T>
-class MOZ_STACK_CLASS AutoVectorRooter : public AutoVectorRooterBase<T>
+class MOZ_RAII AutoVectorRooter : public AutoVectorRooterBase<T>
 {
   public:
     explicit AutoVectorRooter(JSContext* cx
@@ -225,7 +225,7 @@ using IdVector = js::TraceableVector<jsid>;
 using ScriptVector = js::TraceableVector<JSScript*>;
 
 template<class Key, class Value>
-class AutoHashMapRooter : protected AutoGCRooter
+class MOZ_RAII AutoHashMapRooter : protected AutoGCRooter
 {
   private:
     typedef js::HashMap<Key, Value> HashMapImpl;
@@ -349,7 +349,7 @@ class AutoHashMapRooter : protected AutoGCRooter
 };
 
 template<class T>
-class AutoHashSetRooter : protected AutoGCRooter
+class MOZ_RAII AutoHashSetRooter : protected AutoGCRooter
 {
   private:
     typedef js::HashSet<T> HashSetImpl;
@@ -460,7 +460,7 @@ class AutoHashSetRooter : protected AutoGCRooter
 /*
  * Custom rooting behavior for internal and external clients.
  */
-class JS_PUBLIC_API(CustomAutoRooter) : private AutoGCRooter
+class MOZ_RAII JS_PUBLIC_API(CustomAutoRooter) : private AutoGCRooter
 {
   public:
     template <typename CX>
@@ -1070,7 +1070,7 @@ AssertHeapIsIdle(JSContext* cx);
 
 } /* namespace js */
 
-class JSAutoRequest
+class MOZ_RAII JSAutoRequest
 {
   public:
     explicit JSAutoRequest(JSContext* cx
@@ -1409,7 +1409,7 @@ JS_RefreshCrossCompartmentWrappers(JSContext* cx, JS::Handle<JSObject*> obj);
  * the corresponding JS_LeaveCompartment call.
  */
 
-class JS_PUBLIC_API(JSAutoCompartment)
+class MOZ_RAII JS_PUBLIC_API(JSAutoCompartment)
 {
     JSContext* cx_;
     JSCompartment* oldCompartment_;
@@ -1423,7 +1423,7 @@ class JS_PUBLIC_API(JSAutoCompartment)
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-class JS_PUBLIC_API(JSAutoNullableCompartment)
+class MOZ_RAII JS_PUBLIC_API(JSAutoNullableCompartment)
 {
     JSContext* cx_;
     JSCompartment* oldCompartment_;
@@ -4227,7 +4227,7 @@ JS_GetStringEncodingLength(JSContext* cx, JSString* str);
 JS_PUBLIC_API(size_t)
 JS_EncodeStringToBuffer(JSContext* cx, JSString* str, char* buffer, size_t length);
 
-class JSAutoByteString
+class MOZ_RAII JSAutoByteString
 {
   public:
     JSAutoByteString(JSContext* cx, JSString* str
@@ -5039,7 +5039,7 @@ HideScriptedCaller(JSContext* cx);
 extern JS_PUBLIC_API(void)
 UnhideScriptedCaller(JSContext* cx);
 
-class AutoHideScriptedCaller
+class MOZ_RAII AutoHideScriptedCaller
 {
   public:
     explicit AutoHideScriptedCaller(JSContext* cx
diff --git a/js/src/jscntxt.h b/js/src/jscntxt.h
index 8b2ee8e58df..d315c68049b 100644
--- a/js/src/jscntxt.h
+++ b/js/src/jscntxt.h
@@ -33,7 +33,7 @@ typedef HashSet<JSObject*> ObjectSet;
 typedef HashSet<Shape*> ShapeSet;
 
 /* Detects cycles when traversing an object graph. */
-class AutoCycleDetector
+class MOZ_RAII AutoCycleDetector
 {
     JSContext* cx;
     RootedObject obj;
@@ -466,7 +466,7 @@ struct JSContext : public js::ExclusiveContext,
 
 namespace js {
 
-struct AutoResolving {
+struct MOZ_RAII AutoResolving {
   public:
     enum Kind {
         LOOKUP,
@@ -670,7 +670,7 @@ using ShapeVector = js::TraceableVector<Shape*>;
 using StringVector = js::TraceableVector<JSString*>;
 
 /* AutoArrayRooter roots an external array of Values. */
-class AutoArrayRooter : private JS::AutoGCRooter
+class MOZ_RAII AutoArrayRooter : private JS::AutoGCRooter
 {
   public:
     AutoArrayRooter(JSContext* cx, size_t len, Value* vec
@@ -749,7 +749,7 @@ class AutoAssertNoException
 /* Exposed intrinsics for the JITs. */
 bool intrinsic_IsSuspendedStarGenerator(JSContext* cx, unsigned argc, Value* vp);
 
-class AutoLockForExclusiveAccess
+class MOZ_RAII AutoLockForExclusiveAccess
 {
     JSRuntime* runtime;
 
diff --git a/js/src/jscompartment.h b/js/src/jscompartment.h
index 9c87280477c..c1feed7b170 100644
--- a/js/src/jscompartment.h
+++ b/js/src/jscompartment.h
@@ -185,7 +185,7 @@ using NewObjectMetadataState = mozilla::Variant<ImmediateMetadata,
                                                 DelayMetadata,
                                                 PendingMetadata>;
 
-class MOZ_STACK_CLASS AutoSetNewObjectMetadata : private JS::CustomAutoRooter
+class MOZ_RAII AutoSetNewObjectMetadata : private JS::CustomAutoRooter
 {
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
 
@@ -764,7 +764,7 @@ ExclusiveContext::global() const
     return Handle<GlobalObject*>::fromMarkedLocation(compartment_->global_.unsafeGet());
 }
 
-class AssertCompartmentUnchanged
+class MOZ_RAII AssertCompartmentUnchanged
 {
   public:
     explicit AssertCompartmentUnchanged(JSContext* cx
@@ -862,7 +862,7 @@ struct WrapperValue
     Value value;
 };
 
-class AutoWrapperVector : public JS::AutoVectorRooterBase<WrapperValue>
+class MOZ_RAII AutoWrapperVector : public JS::AutoVectorRooterBase<WrapperValue>
 {
   public:
     explicit AutoWrapperVector(JSContext* cx
@@ -875,7 +875,7 @@ class AutoWrapperVector : public JS::AutoVectorRooterBase<WrapperValue>
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-class AutoWrapperRooter : private JS::AutoGCRooter {
+class MOZ_RAII AutoWrapperRooter : private JS::AutoGCRooter {
   public:
     AutoWrapperRooter(JSContext* cx, WrapperValue v
                       MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/js/src/jsfriendapi.h b/js/src/jsfriendapi.h
index bd75bf74a93..beb62e339d4 100644
--- a/js/src/jsfriendapi.h
+++ b/js/src/jsfriendapi.h
@@ -2694,7 +2694,7 @@ typedef void
 JS_FRIEND_API(void)
 SetCTypesActivityCallback(JSRuntime* rt, CTypesActivityCallback cb);
 
-class JS_FRIEND_API(AutoCTypesActivityCallback) {
+class MOZ_RAII JS_FRIEND_API(AutoCTypesActivityCallback) {
   private:
     JSContext* cx;
     CTypesActivityCallback callback;
diff --git a/js/src/jsgc.h b/js/src/jsgc.h
index 7acaac005d9..908e9e801a8 100644
--- a/js/src/jsgc.h
+++ b/js/src/jsgc.h
@@ -1374,7 +1374,7 @@ NewMemoryStatisticsObject(JSContext* cx);
 
 #ifdef DEBUG
 /* Use this to avoid assertions when manipulating the wrapper map. */
-class AutoDisableProxyCheck
+class MOZ_RAII AutoDisableProxyCheck
 {
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
     gc::GCRuntime& gc;
diff --git a/js/src/jsutil.h b/js/src/jsutil.h
index 431f186b6bc..3e163c86cb0 100644
--- a/js/src/jsutil.h
+++ b/js/src/jsutil.h
@@ -168,7 +168,7 @@ ImplicitCast(U& u)
 }
 
 template<typename T>
-class AutoScopedAssign
+class MOZ_RAII AutoScopedAssign
 {
   public:
     AutoScopedAssign(T* addr, const T& value
diff --git a/js/src/shell/js.cpp b/js/src/shell/js.cpp
index a05928680ec..ebe82df3d9f 100644
--- a/js/src/shell/js.cpp
+++ b/js/src/shell/js.cpp
@@ -3400,7 +3400,7 @@ runOffThreadScript(JSContext* cx, unsigned argc, Value* vp)
     return JS_ExecuteScript(cx, script, args.rval());
 }
 
-struct FreeOnReturn
+struct MOZ_RAII FreeOnReturn
 {
     JSContext* cx;
     const char* ptr;
diff --git a/js/src/vm/Debugger.cpp b/js/src/vm/Debugger.cpp
index da0d7007df2..716decde200 100644
--- a/js/src/vm/Debugger.cpp
+++ b/js/src/vm/Debugger.cpp
@@ -1824,7 +1824,7 @@ Debugger::slowPathPromiseHook(JSContext* cx, Hook hook, HandleObject promise)
 
 /*** Debugger code invalidation for observing execution ******************************************/
 
-class MOZ_STACK_CLASS ExecutionObservableCompartments : public Debugger::ExecutionObservableSet
+class MOZ_RAII ExecutionObservableCompartments : public Debugger::ExecutionObservableSet
 {
     HashSet<JSCompartment*> compartments_;
     HashSet<Zone*> zones_;
@@ -1858,7 +1858,7 @@ class MOZ_STACK_CLASS ExecutionObservableCompartments : public Debugger::Executi
 // represents the stack frames that need to be bailed out or marked as
 // debuggees, and the scripts that need to be recompiled, taking inlining into
 // account.
-class MOZ_STACK_CLASS ExecutionObservableFrame : public Debugger::ExecutionObservableSet
+class MOZ_RAII ExecutionObservableFrame : public Debugger::ExecutionObservableSet
 {
     AbstractFramePtr frame_;
 
@@ -1919,7 +1919,7 @@ class MOZ_STACK_CLASS ExecutionObservableFrame : public Debugger::ExecutionObser
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-class MOZ_STACK_CLASS ExecutionObservableScript : public Debugger::ExecutionObservableSet
+class MOZ_RAII ExecutionObservableScript : public Debugger::ExecutionObservableSet
 {
     RootedScript script_;
 
diff --git a/js/src/vm/HelperThreads.h b/js/src/vm/HelperThreads.h
index 9fdfb275fd7..30fcfc49371 100644
--- a/js/src/vm/HelperThreads.h
+++ b/js/src/vm/HelperThreads.h
@@ -412,7 +412,7 @@ struct AutoEnqueuePendingParseTasksAfterGC {
 bool
 StartOffThreadCompression(ExclusiveContext* cx, SourceCompressionTask* task);
 
-class AutoLockHelperThreadState
+class MOZ_RAII AutoLockHelperThreadState
 {
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 
@@ -428,7 +428,7 @@ class AutoLockHelperThreadState
     }
 };
 
-class AutoUnlockHelperThreadState
+class MOZ_RAII AutoUnlockHelperThreadState
 {
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 
diff --git a/js/src/vm/Interpreter.cpp b/js/src/vm/Interpreter.cpp
index 34416ea63bf..724218e084f 100644
--- a/js/src/vm/Interpreter.cpp
+++ b/js/src/vm/Interpreter.cpp
@@ -375,7 +375,7 @@ namespace js {
 // All mutable state is stored in `Runtime::stopwatch` (per-process
 // performance stats and logistics) and in `PerformanceGroup` (per
 // group performance stats).
-class AutoStopwatch final
+class MOZ_RAII AutoStopwatch final
 {
     // The context with which this object was initialized.
     // Non-null.
diff --git a/js/src/vm/RegExpStatics.h b/js/src/vm/RegExpStatics.h
index 1b268bd9fd4..430e4b3527e 100644
--- a/js/src/vm/RegExpStatics.h
+++ b/js/src/vm/RegExpStatics.h
@@ -186,7 +186,7 @@ class RegExpStatics
     }
 };
 
-class AutoRegExpStaticsBuffer : private JS::CustomAutoRooter
+class MOZ_RAII AutoRegExpStaticsBuffer : private JS::CustomAutoRooter
 {
   public:
     explicit AutoRegExpStaticsBuffer(JSContext* cx
diff --git a/js/src/vm/Runtime.h b/js/src/vm/Runtime.h
index 7aef80c5df1..68d1e366e30 100644
--- a/js/src/vm/Runtime.h
+++ b/js/src/vm/Runtime.h
@@ -1864,7 +1864,7 @@ FreeOp::freeLater(void* p)
  * Note that the lock may be temporarily released by use of AutoUnlockGC when
  * passed a non-const reference to this class.
  */
-class MOZ_STACK_CLASS AutoLockGC
+class MOZ_RAII AutoLockGC
 {
   public:
     explicit AutoLockGC(JSRuntime* rt
@@ -1903,7 +1903,7 @@ class MOZ_STACK_CLASS AutoLockGC
     AutoLockGC& operator=(const AutoLockGC&) = delete;
 };
 
-class MOZ_STACK_CLASS AutoUnlockGC
+class MOZ_RAII AutoUnlockGC
 {
   public:
     explicit AutoUnlockGC(AutoLockGC& lock
@@ -1926,7 +1926,7 @@ class MOZ_STACK_CLASS AutoUnlockGC
     AutoUnlockGC& operator=(const AutoUnlockGC&) = delete;
 };
 
-class MOZ_STACK_CLASS AutoKeepAtoms
+class MOZ_RAII AutoKeepAtoms
 {
     PerThreadData* pt;
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
@@ -2095,7 +2095,7 @@ extern const JSSecurityCallbacks NullSecurityCallbacks;
 
 // Debugging RAII class which marks the current thread as performing an Ion
 // compilation, for use by CurrentThreadCan{Read,Write}CompilationData
-class AutoEnterIonCompilation
+class MOZ_RAII AutoEnterIonCompilation
 {
   public:
     explicit AutoEnterIonCompilation(bool safeForMinorGC
diff --git a/js/src/vm/SPSProfiler.h b/js/src/vm/SPSProfiler.h
index a7106084d08..a5e6bc78c6d 100644
--- a/js/src/vm/SPSProfiler.h
+++ b/js/src/vm/SPSProfiler.h
@@ -227,7 +227,7 @@ class AutoSPSLock
  * This class is used to suppress profiler sampling during
  * critical sections where stack state is not valid.
  */
-class AutoSuppressProfilerSampling
+class MOZ_RAII AutoSuppressProfilerSampling
 {
   public:
     explicit AutoSuppressProfilerSampling(JSContext* cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
@@ -260,7 +260,7 @@ SPSProfiler::stringsReset()
  * that we're about to enter JS function calls. This is the only time in which a
  * valid stack pointer is pushed to the sampling stack.
  */
-class SPSEntryMarker
+class MOZ_RAII SPSEntryMarker
 {
   public:
     explicit SPSEntryMarker(JSRuntime* rt,
@@ -279,7 +279,7 @@ class SPSEntryMarker
  * being entered via OSR.  It marks the current top pseudostack entry as
  * OSR-ed
  */
-class SPSBaselineOSRMarker
+class MOZ_RAII SPSBaselineOSRMarker
 {
   public:
     explicit SPSBaselineOSRMarker(JSRuntime* rt, bool hasSPSFrame
diff --git a/js/src/vm/SavedStacks.h b/js/src/vm/SavedStacks.h
index 359665eb391..977937c0497 100644
--- a/js/src/vm/SavedStacks.h
+++ b/js/src/vm/SavedStacks.h
@@ -181,7 +181,7 @@ class SavedStacks {
     // Similar to mozilla::ReentrancyGuard, but instead of asserting against
     // reentrancy, just change the behavior of SavedStacks::saveCurrentStack to
     // return a nullptr SavedFrame.
-    struct MOZ_STACK_CLASS AutoReentrancyGuard {
+    struct MOZ_RAII AutoReentrancyGuard {
         MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
         SavedStacks& stacks;
 
diff --git a/js/src/vm/ScopeObject.h b/js/src/vm/ScopeObject.h
index e215af0eec8..cdefbbb4065 100644
--- a/js/src/vm/ScopeObject.h
+++ b/js/src/vm/ScopeObject.h
@@ -825,7 +825,7 @@ CloneNestedScopeObject(JSContext* cx, HandleObject enclosingScope, Handle<Nested
 // whether the current scope is within the extent of this initial frame.
 // Here, "frame" means a single activation of: a function, eval, or global
 // code.
-class ScopeIter
+class MOZ_RAII ScopeIter
 {
     StaticScopeIter<CanGC> ssi_;
     RootedObject scope_;
diff --git a/js/src/vm/Shape.h b/js/src/vm/Shape.h
index 99203669a27..b17874ddfe2 100644
--- a/js/src/vm/Shape.h
+++ b/js/src/vm/Shape.h
@@ -982,7 +982,7 @@ StackBaseShape::StackBaseShape(Shape* shape)
     compartment(shape->compartment())
 {}
 
-class AutoRooterGetterSetter
+class MOZ_RAII AutoRooterGetterSetter
 {
     class Inner : private JS::CustomAutoRooter
     {
diff --git a/js/src/vm/TraceLogging.h b/js/src/vm/TraceLogging.h
index 1ac21a16a83..9ba78edcfb5 100644
--- a/js/src/vm/TraceLogging.h
+++ b/js/src/vm/TraceLogging.h
@@ -439,7 +439,7 @@ inline void TraceLogStopEventPrivate(TraceLoggerThread* logger, uint32_t id) {
 }
 
 // Automatic logging at the start and end of function call.
-class AutoTraceLog
+class MOZ_RAII AutoTraceLog
 {
 #ifdef JS_TRACE_LOGGING
     TraceLoggerThread* logger;
diff --git a/js/src/vm/TraceLoggingGraph.cpp b/js/src/vm/TraceLoggingGraph.cpp
index d1b7f2e5db9..d5a7b8b7350 100644
--- a/js/src/vm/TraceLoggingGraph.cpp
+++ b/js/src/vm/TraceLoggingGraph.cpp
@@ -24,7 +24,7 @@ using mozilla::NativeEndian;
 
 TraceLoggerGraphState* traceLoggerGraphState = nullptr;
 
-class AutoTraceLoggerGraphStateLock
+class MOZ_RAII AutoTraceLoggerGraphStateLock
 {
   TraceLoggerGraphState* graph;
 
diff --git a/js/xpconnect/src/xpcprivate.h b/js/xpconnect/src/xpcprivate.h
index ac69ebbb843..15e118df71e 100644
--- a/js/xpconnect/src/xpcprivate.h
+++ b/js/xpconnect/src/xpcprivate.h
@@ -3040,7 +3040,7 @@ private:
 /******************************************************************************
  * Handles pre/post script processing.
  */
-class MOZ_STACK_CLASS AutoScriptEvaluate
+class MOZ_RAII AutoScriptEvaluate
 {
 public:
     /**
@@ -3077,7 +3077,7 @@ private:
 };
 
 /***************************************************************************/
-class MOZ_STACK_CLASS AutoResolveName
+class MOZ_RAII AutoResolveName
 {
 public:
     AutoResolveName(XPCCallContext& ccx, JS::HandleId name
diff --git a/layout/generic/Selection.h b/layout/generic/Selection.h
index 62663c01fa7..b0cfacd3c3e 100644
--- a/layout/generic/Selection.h
+++ b/layout/generic/Selection.h
@@ -217,7 +217,7 @@ public:
   nsresult     NotifySelectionListeners();
 
   friend struct AutoApplyUserSelectStyle;
-  struct MOZ_STACK_CLASS AutoApplyUserSelectStyle
+  struct MOZ_RAII AutoApplyUserSelectStyle
   {
     explicit AutoApplyUserSelectStyle(Selection* aSelection
                              MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/layout/generic/nsFlexContainerFrame.cpp b/layout/generic/nsFlexContainerFrame.cpp
index 959266d45a9..0f442bc07fa 100644
--- a/layout/generic/nsFlexContainerFrame.cpp
+++ b/layout/generic/nsFlexContainerFrame.cpp
@@ -3623,7 +3623,7 @@ nsFlexContainerFrame::Reflow(nsPresContext*           aPresContext,
 // RAII class to clean up a list of FlexLines.
 // Specifically, this removes each line from the list, deletes all the
 // FlexItems in its list, and deletes the FlexLine.
-class MOZ_STACK_CLASS AutoFlexLineListClearer
+class MOZ_RAII AutoFlexLineListClearer
 {
 public:
   explicit AutoFlexLineListClearer(LinkedList<FlexLine>& aLines
diff --git a/layout/generic/nsSelection.cpp b/layout/generic/nsSelection.cpp
index 0d2fa0afd67..efe9bac6c56 100644
--- a/layout/generic/nsSelection.cpp
+++ b/layout/generic/nsSelection.cpp
@@ -332,7 +332,7 @@ IsValidSelectionPoint(nsFrameSelection *aFrameSel, nsINode *aNode)
 }
 
 namespace mozilla {
-struct MOZ_STACK_CLASS AutoPrepareFocusRange
+struct MOZ_RAII AutoPrepareFocusRange
 {
   AutoPrepareFocusRange(Selection* aSelection,
                         bool aContinueSelection,
diff --git a/layout/style/nsCSSParser.cpp b/layout/style/nsCSSParser.cpp
index 4fe15f6de17..1b776b58a17 100644
--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -428,7 +428,7 @@ protected:
    * state (in a CSSParserInputState object), and it restores the parser to
    * that state when destructed, unless "DoNotRestore()" has been called.
   */
-  class MOZ_STACK_CLASS nsAutoCSSParserInputStateRestorer {
+  class MOZ_RAII nsAutoCSSParserInputStateRestorer {
     public:
       explicit nsAutoCSSParserInputStateRestorer(CSSParserImpl* aParser
                                                  MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
@@ -476,7 +476,7 @@ protected:
    * XXXdholbert we could also change this & report errors, if needed. Might
    * want to customize the error reporting somehow though.
    */
-  class MOZ_STACK_CLASS nsAutoScannerChanger {
+  class MOZ_RAII nsAutoScannerChanger {
     public:
       nsAutoScannerChanger(CSSParserImpl* aParser,
                            const nsAString& aStringToScan
diff --git a/layout/style/nsRuleProcessorData.h b/layout/style/nsRuleProcessorData.h
index b7f9cc3ea19..b8516776cc6 100644
--- a/layout/style/nsRuleProcessorData.h
+++ b/layout/style/nsRuleProcessorData.h
@@ -225,7 +225,7 @@ struct MOZ_STACK_CLASS TreeMatchContext {
   }
 
   /* Helper class for maintaining the ancestor state */
-  class MOZ_STACK_CLASS AutoAncestorPusher {
+  class MOZ_RAII AutoAncestorPusher {
   public:
     explicit AutoAncestorPusher(TreeMatchContext& aTreeMatchContext
                                 MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
@@ -295,7 +295,7 @@ struct MOZ_STACK_CLASS TreeMatchContext {
    * in cases where we may or may not want to be skipping flex/grid-item
    * style fixup for a particular chunk of code).
    */
-  class MOZ_STACK_CLASS AutoParentDisplayBasedStyleFixupSkipper {
+  class MOZ_RAII AutoParentDisplayBasedStyleFixupSkipper {
   public:
     explicit AutoParentDisplayBasedStyleFixupSkipper(TreeMatchContext& aTreeMatchContext,
                                                      bool aSkipParentDisplayBasedStyleFixup = true
diff --git a/layout/svg/nsSVGClipPathFrame.h b/layout/svg/nsSVGClipPathFrame.h
index 8dad2aff791..2674a140ff3 100644
--- a/layout/svg/nsSVGClipPathFrame.h
+++ b/layout/svg/nsSVGClipPathFrame.h
@@ -104,7 +104,7 @@ public:
   // automatically sets and clears the mInUse flag on the clip path frame
   // (to prevent nasty reference loops). It's easy to mess this up
   // and break things, so this helper makes the code far more robust.
-  class MOZ_STACK_CLASS AutoClipPathReferencer
+  class MOZ_RAII AutoClipPathReferencer
   {
   public:
     explicit AutoClipPathReferencer(nsSVGClipPathFrame *aFrame
diff --git a/layout/svg/nsSVGFilterFrame.cpp b/layout/svg/nsSVGFilterFrame.cpp
index f21d0e137fa..741e91c374e 100644
--- a/layout/svg/nsSVGFilterFrame.cpp
+++ b/layout/svg/nsSVGFilterFrame.cpp
@@ -27,7 +27,7 @@ NS_NewSVGFilterFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 
 NS_IMPL_FRAMEARENA_HELPERS(nsSVGFilterFrame)
 
-class MOZ_STACK_CLASS nsSVGFilterFrame::AutoFilterReferencer
+class MOZ_RAII nsSVGFilterFrame::AutoFilterReferencer
 {
 public:
   explicit AutoFilterReferencer(nsSVGFilterFrame *aFrame MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
diff --git a/layout/svg/nsSVGGradientFrame.cpp b/layout/svg/nsSVGGradientFrame.cpp
index 528acaeaecb..360c594efa1 100644
--- a/layout/svg/nsSVGGradientFrame.cpp
+++ b/layout/svg/nsSVGGradientFrame.cpp
@@ -24,7 +24,7 @@ using namespace mozilla::dom;
 //----------------------------------------------------------------------
 // Helper classes
 
-class MOZ_STACK_CLASS nsSVGGradientFrame::AutoGradientReferencer
+class MOZ_RAII nsSVGGradientFrame::AutoGradientReferencer
 {
 public:
   explicit AutoGradientReferencer(nsSVGGradientFrame *aFrame
diff --git a/layout/svg/nsSVGMarkerFrame.h b/layout/svg/nsSVGMarkerFrame.h
index 0e31c37140e..d23fb9f7cbb 100644
--- a/layout/svg/nsSVGMarkerFrame.h
+++ b/layout/svg/nsSVGMarkerFrame.h
@@ -110,7 +110,7 @@ private:
   // prevent nasty reference loops) as well as the reference to the marked
   // frame and its coordinate context. It's easy to mess this up
   // and break things, so this helper makes the code far more robust.
-  class MOZ_STACK_CLASS AutoMarkerReferencer
+  class MOZ_RAII AutoMarkerReferencer
   {
   public:
     AutoMarkerReferencer(nsSVGMarkerFrame *aFrame,
diff --git a/layout/svg/nsSVGMaskFrame.h b/layout/svg/nsSVGMaskFrame.h
index a93c96898db..f3e4cfbef1d 100644
--- a/layout/svg/nsSVGMaskFrame.h
+++ b/layout/svg/nsSVGMaskFrame.h
@@ -100,7 +100,7 @@ private:
   // automatically sets and clears the mInUse flag on the mask frame
   // (to prevent nasty reference loops). It's easy to mess this up
   // and break things, so this helper makes the code far more robust.
-  class MOZ_STACK_CLASS AutoMaskReferencer
+  class MOZ_RAII AutoMaskReferencer
   {
   public:
     explicit AutoMaskReferencer(nsSVGMaskFrame *aFrame
diff --git a/layout/svg/nsSVGPatternFrame.cpp b/layout/svg/nsSVGPatternFrame.cpp
index 39b5ecd5ca1..47e1b205e29 100644
--- a/layout/svg/nsSVGPatternFrame.cpp
+++ b/layout/svg/nsSVGPatternFrame.cpp
@@ -32,7 +32,7 @@ using namespace mozilla::gfx;
 //----------------------------------------------------------------------
 // Helper classes
 
-class MOZ_STACK_CLASS nsSVGPatternFrame::AutoPatternReferencer
+class MOZ_RAII nsSVGPatternFrame::AutoPatternReferencer
 {
 public:
   explicit AutoPatternReferencer(nsSVGPatternFrame *aFrame
diff --git a/layout/svg/nsSVGUtils.h b/layout/svg/nsSVGUtils.h
index 177b3efd54c..a450c795cc5 100644
--- a/layout/svg/nsSVGUtils.h
+++ b/layout/svg/nsSVGUtils.h
@@ -137,7 +137,7 @@ private:
 // GRRR WINDOWS HATE HATE HATE
 #undef CLIP_MASK
 
-class MOZ_STACK_CLASS SVGAutoRenderState
+class MOZ_RAII SVGAutoRenderState
 {
   typedef mozilla::gfx::DrawTarget DrawTarget;
 
diff --git a/mfbt/ReentrancyGuard.h b/mfbt/ReentrancyGuard.h
index d5142073c1d..9963974e730 100644
--- a/mfbt/ReentrancyGuard.h
+++ b/mfbt/ReentrancyGuard.h
@@ -16,7 +16,7 @@
 namespace mozilla {
 
 /* Useful for implementing containers that assert non-reentrancy */
-class ReentrancyGuard
+class MOZ_RAII ReentrancyGuard
 {
   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 #ifdef DEBUG
diff --git a/mfbt/ScopeExit.h b/mfbt/ScopeExit.h
index ff38bf47740..7aff82d8a1d 100644
--- a/mfbt/ScopeExit.h
+++ b/mfbt/ScopeExit.h
@@ -86,7 +86,7 @@
 namespace mozilla {
 
 template <typename ExitFunction>
-class ScopeExit {
+class MOZ_STACK_CLASS ScopeExit {
   ExitFunction mExitFunction;
   bool mExecuteOnDestruction;
   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
diff --git a/mfbt/Scoped.h b/mfbt/Scoped.h
index 7855cde9500..de8a166f06d 100644
--- a/mfbt/Scoped.h
+++ b/mfbt/Scoped.h
@@ -77,7 +77,7 @@ namespace mozilla {
  *   }
  */
 template<typename Traits>
-class Scoped
+class MOZ_NON_TEMPORARY_CLASS Scoped
 {
 public:
   typedef typename Traits::type Resource;
@@ -187,7 +187,7 @@ private:
  */
 #define SCOPED_TEMPLATE(name, Traits)                                         \
 template<typename Type>                                                       \
-struct name : public mozilla::Scoped<Traits<Type> >                           \
+struct MOZ_NON_TEMPORARY_CLASS name : public mozilla::Scoped<Traits<Type> >   \
 {                                                                             \
   typedef mozilla::Scoped<Traits<Type> > Super;                               \
   typedef typename Super::Resource Resource;                                  \
diff --git a/mozglue/build/WindowsDllBlocklist.h b/mozglue/build/WindowsDllBlocklist.h
index e33ec908fe7..b66704764ff 100644
--- a/mozglue/build/WindowsDllBlocklist.h
+++ b/mozglue/build/WindowsDllBlocklist.h
@@ -18,7 +18,7 @@ NS_IMPORT void DllBlocklist_Initialize();
 NS_IMPORT void DllBlocklist_SetInXPCOMLoadOnMainThread(bool inXPCOMLoadOnMainThread);
 NS_IMPORT void DllBlocklist_WriteNotes(HANDLE file);
 
-class AutoSetXPCOMLoadOnMainThread
+class MOZ_RAII AutoSetXPCOMLoadOnMainThread
 {
   public:
     AutoSetXPCOMLoadOnMainThread(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM) {
diff --git a/toolkit/components/osfile/NativeOSFileInternals.cpp b/toolkit/components/osfile/NativeOSFileInternals.cpp
index 0b912a0b756..21932ee086e 100644
--- a/toolkit/components/osfile/NativeOSFileInternals.cpp
+++ b/toolkit/components/osfile/NativeOSFileInternals.cpp
@@ -91,7 +91,7 @@ struct ScopedArrayBufferContentsTraits {
   }
 };
 
-struct ScopedArrayBufferContents: public Scoped<ScopedArrayBufferContentsTraits> {
+struct MOZ_NON_TEMPORARY_CLASS ScopedArrayBufferContents: public Scoped<ScopedArrayBufferContentsTraits> {
   explicit ScopedArrayBufferContents(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM):
     Scoped<ScopedArrayBufferContentsTraits>(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_TO_PARENT)
   { }
diff --git a/toolkit/components/telemetry/Telemetry.h b/toolkit/components/telemetry/Telemetry.h
index 7965718d851..f6a863efb3e 100644
--- a/toolkit/components/telemetry/Telemetry.h
+++ b/toolkit/components/telemetry/Telemetry.h
@@ -118,7 +118,7 @@ struct AccumulateDelta_impl<Microsecond>
 
 
 template<ID id, TimerResolution res = Millisecond>
-class AutoTimer {
+class MOZ_RAII AutoTimer {
 public:
   explicit AutoTimer(TimeStamp aStart = TimeStamp::Now() MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : start(aStart)
@@ -148,7 +148,7 @@ private:
 };
 
 template<ID id>
-class AutoCounter {
+class MOZ_RAII AutoCounter {
 public:
   explicit AutoCounter(uint32_t counterStart = 0 MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
     : counter(counterStart)
diff --git a/toolkit/devtools/heapsnapshot/AutoMemMap.h b/toolkit/devtools/heapsnapshot/AutoMemMap.h
index e6943a41224..a086a4590b0 100644
--- a/toolkit/devtools/heapsnapshot/AutoMemMap.h
+++ b/toolkit/devtools/heapsnapshot/AutoMemMap.h
@@ -28,7 +28,7 @@ namespace devtools {
 //       doStuffWithMappedMemory(mm.address());
 //     }
 //     // The memory is automatically unmapped when the AutoMemMap leaves scope.
-class MOZ_STACK_CLASS AutoMemMap
+class MOZ_RAII AutoMemMap
 {
   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
 
diff --git a/tools/profiler/public/GeckoProfilerImpl.h b/tools/profiler/public/GeckoProfilerImpl.h
index 0d81b7d425e..00131766ebc 100644
--- a/tools/profiler/public/GeckoProfilerImpl.h
+++ b/tools/profiler/public/GeckoProfilerImpl.h
@@ -377,7 +377,7 @@ static inline void profiler_tracing(const char* aCategory, const char* aInfo,
 
 namespace mozilla {
 
-class MOZ_STACK_CLASS GeckoProfilerTracingRAII {
+class MOZ_RAII GeckoProfilerTracingRAII {
 public:
   GeckoProfilerTracingRAII(const char* aCategory, const char* aInfo,
                            mozilla::UniquePtr<ProfilerBacktrace> aBacktrace
diff --git a/xpcom/glue/AutoRestore.h b/xpcom/glue/AutoRestore.h
index 2a872298469..9ea790035c0 100644
--- a/xpcom/glue/AutoRestore.h
+++ b/xpcom/glue/AutoRestore.h
@@ -27,7 +27,7 @@ namespace mozilla {
  *   }
  */
 template<class T>
-class MOZ_STACK_CLASS AutoRestore
+class MOZ_RAII AutoRestore
 {
 private:
   T& mLocation;
diff --git a/xpcom/glue/Mutex.h b/xpcom/glue/Mutex.h
index a5ed05f36a3..734dbf3cf8b 100644
--- a/xpcom/glue/Mutex.h
+++ b/xpcom/glue/Mutex.h
@@ -145,7 +145,7 @@ private:
  * MUCH PREFERRED to bare calls to Mutex.Lock and Unlock.
  */
 template<typename T>
-class MOZ_STACK_CLASS BaseAutoLock
+class MOZ_RAII BaseAutoLock
 {
 public:
   /**
@@ -190,7 +190,7 @@ typedef BaseAutoLock<OffTheBooksMutex> OffTheBooksMutexAutoLock;
  * MUCH PREFERRED to bare calls to Mutex.Unlock and Lock.
  */
 template<typename T>
-class MOZ_STACK_CLASS BaseAutoUnlock
+class MOZ_RAII BaseAutoUnlock
 {
 public:
   explicit BaseAutoUnlock(T& aLock MOZ_GUARD_OBJECT_NOTIFIER_PARAM)