Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1484 insertions, 0 deletions

diff --git a/xpcom/base/nsISupportsImpl.h b/xpcom/base/nsISupportsImpl.h
new file mode 100644
index 0000000000..27ff85b385
--- /dev/null
+++ b/xpcom/base/nsISupportsImpl.h
@@ -0,0 +1,1484 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+// IWYU pragma: private, include "nsISupports.h"
+
+#ifndef nsISupportsImpl_h__
+#define nsISupportsImpl_h__
+
+#include "nscore.h"
+#include "nsISupports.h"
+#include "nsISupportsUtils.h"
+
+#if !defined(XPCOM_GLUE_AVOID_NSPR)
+#  include "prthread.h" /* needed for cargo-culting headers */
+#endif
+
+#include "nsDebug.h"
+#include "nsXPCOM.h"
+#include <atomic>
+#include <type_traits>
+#include "mozilla/Attributes.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/Compiler.h"
+#include "mozilla/Likely.h"
+#include "mozilla/MacroArgs.h"
+#include "mozilla/MacroForEach.h"
+
+#define MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(X)            \
+  static_assert(!std::is_destructible_v<X>,              \
+                "Reference-counted class " #X            \
+                " should not have a public destructor. " \
+                "Make this class's destructor non-public");
+
+inline nsISupports* ToSupports(decltype(nullptr)) { return nullptr; }
+
+inline nsISupports* ToSupports(nsISupports* aSupports) { return aSupports; }
+
+////////////////////////////////////////////////////////////////////////////////
+// Macros to help detect thread-safety:
+
+#ifdef MOZ_THREAD_SAFETY_OWNERSHIP_CHECKS_SUPPORTED
+
+#  include "prthread.h" /* needed for thread-safety checks */
+
+class nsAutoOwningThread {
+ public:
+  nsAutoOwningThread();
+
+  // We move the actual assertion checks out-of-line to minimize code bloat,
+  // but that means we have to pass a non-literal string to MOZ_CRASH_UNSAFE.
+  // To make that more safe, the public interface requires a literal string
+  // and passes that to the private interface; we can then be assured that we
+  // effectively are passing a literal string to MOZ_CRASH_UNSAFE.
+  template <int N>
+  void AssertOwnership(const char (&aMsg)[N]) const {
+    AssertCurrentThreadOwnsMe(aMsg);
+  }
+
+  bool IsCurrentThread() const;
+
+ private:
+  void AssertCurrentThreadOwnsMe(const char* aMsg) const;
+
+  void* mThread;
+};
+
+class nsISerialEventTarget;
+class nsAutoOwningEventTarget {
+ public:
+  nsAutoOwningEventTarget();
+  ~nsAutoOwningEventTarget();
+
+  // We move the actual assertion checks out-of-line to minimize code bloat,
+  // but that means we have to pass a non-literal string to MOZ_CRASH_UNSAFE.
+  // To make that more safe, the public interface requires a literal string
+  // and passes that to the private interface; we can then be assured that we
+  // effectively are passing a literal string to MOZ_CRASH_UNSAFE.
+  template <int N>
+  void AssertOwnership(const char (&aMsg)[N]) const {
+    AssertCurrentThreadOwnsMe(aMsg);
+  }
+
+  bool IsCurrentThread() const;
+
+ private:
+  void AssertCurrentThreadOwnsMe(const char* aMsg) const;
+
+  nsISerialEventTarget* mTarget;
+};
+
+#  define NS_DECL_OWNINGTHREAD nsAutoOwningThread _mOwningThread;
+#  define NS_DECL_OWNINGEVENTTARGET nsAutoOwningEventTarget _mOwningThread;
+#  define NS_ASSERT_OWNINGTHREAD(_class) \
+    _mOwningThread.AssertOwnership(#_class " not thread-safe")
+#else  // !MOZ_THREAD_SAFETY_OWNERSHIP_CHECKS_SUPPORTED
+
+#  define NS_DECL_OWNINGTHREAD      /* nothing */
+#  define NS_DECL_OWNINGEVENTTARGET /* nothing */
+#  define NS_ASSERT_OWNINGTHREAD(_class) ((void)0)
+
+#endif  // MOZ_THREAD_SAFETY_OWNERSHIP_CHECKS_SUPPORTED
+
+// Macros for reference-count and constructor logging
+
+#if defined(NS_BUILD_REFCNT_LOGGING)
+
+#  define NS_LOG_ADDREF(_p, _rc, _type, _size) \
+    NS_LogAddRef((_p), (_rc), (_type), (uint32_t)(_size))
+
+#  define NS_LOG_RELEASE(_p, _rc, _type) NS_LogRelease((_p), (_rc), (_type))
+
+#  define MOZ_ASSERT_CLASSNAME(_type)     \
+    static_assert(std::is_class_v<_type>, \
+                  "Token '" #_type "' is not a class type.")
+
+#  define MOZ_ASSERT_NOT_ISUPPORTS(_type)                                     \
+    static_assert(!std::is_base_of<nsISupports, _type>::value,                \
+                  "nsISupports classes don't need to call MOZ_COUNT_CTOR or " \
+                  "MOZ_COUNT_DTOR");
+
+// Note that the following constructor/destructor logging macros are redundant
+// for refcounted objects that log via the NS_LOG_ADDREF/NS_LOG_RELEASE macros.
+// Refcount logging is preferred.
+#  define MOZ_COUNT_CTOR(_type)                       \
+    do {                                              \
+      MOZ_ASSERT_CLASSNAME(_type);                    \
+      MOZ_ASSERT_NOT_ISUPPORTS(_type);                \
+      NS_LogCtor((void*)this, #_type, sizeof(*this)); \
+    } while (0)
+
+#  define MOZ_COUNT_CTOR_INHERITED(_type, _base)                      \
+    do {                                                              \
+      MOZ_ASSERT_CLASSNAME(_type);                                    \
+      MOZ_ASSERT_CLASSNAME(_base);                                    \
+      MOZ_ASSERT_NOT_ISUPPORTS(_type);                                \
+      NS_LogCtor((void*)this, #_type, sizeof(*this) - sizeof(_base)); \
+    } while (0)
+
+#  define MOZ_LOG_CTOR(_ptr, _name, _size)   \
+    do {                                     \
+      NS_LogCtor((void*)_ptr, _name, _size); \
+    } while (0)
+
+#  define MOZ_COUNT_DTOR(_type)                       \
+    do {                                              \
+      MOZ_ASSERT_CLASSNAME(_type);                    \
+      MOZ_ASSERT_NOT_ISUPPORTS(_type);                \
+      NS_LogDtor((void*)this, #_type, sizeof(*this)); \
+    } while (0)
+
+#  define MOZ_COUNT_DTOR_INHERITED(_type, _base)                      \
+    do {                                                              \
+      MOZ_ASSERT_CLASSNAME(_type);                                    \
+      MOZ_ASSERT_CLASSNAME(_base);                                    \
+      MOZ_ASSERT_NOT_ISUPPORTS(_type);                                \
+      NS_LogDtor((void*)this, #_type, sizeof(*this) - sizeof(_base)); \
+    } while (0)
+
+#  define MOZ_LOG_DTOR(_ptr, _name, _size)   \
+    do {                                     \
+      NS_LogDtor((void*)_ptr, _name, _size); \
+    } while (0)
+
+#  define MOZ_COUNTED_DEFAULT_CTOR(_type) \
+    _type() { MOZ_COUNT_CTOR(_type); }
+
+#  define MOZ_COUNTED_DTOR_META(_type, _prefix, _postfix) \
+    _prefix ~_type() _postfix { MOZ_COUNT_DTOR(_type); }
+#  define MOZ_COUNTED_DTOR_NESTED(_type, _nestedName) \
+    ~_type() { MOZ_COUNT_DTOR(_nestedName); }
+
+/* nsCOMPtr.h allows these macros to be defined by clients
+ * These logging functions require dynamic_cast<void*>, so they don't
+ * do anything useful if we don't have dynamic_cast<void*>.
+ * Note: The explicit comparison to nullptr is needed to avoid warnings
+ *       when _p is a nullptr itself. */
+#  define NSCAP_LOG_ASSIGNMENT(_c, _p) \
+    if (_p != nullptr) NS_LogCOMPtrAddRef((_c), ToSupports(_p))
+
+#  define NSCAP_LOG_RELEASE(_c, _p) \
+    if (_p) NS_LogCOMPtrRelease((_c), ToSupports(_p))
+
+#else /* !NS_BUILD_REFCNT_LOGGING */
+
+#  define NS_LOG_ADDREF(_p, _rc, _type, _size)
+#  define NS_LOG_RELEASE(_p, _rc, _type)
+#  define MOZ_COUNT_CTOR(_type)
+#  define MOZ_COUNT_CTOR_INHERITED(_type, _base)
+#  define MOZ_LOG_CTOR(_ptr, _name, _size)
+#  define MOZ_COUNT_DTOR(_type)
+#  define MOZ_COUNT_DTOR_INHERITED(_type, _base)
+#  define MOZ_LOG_DTOR(_ptr, _name, _size)
+#  define MOZ_COUNTED_DEFAULT_CTOR(_type) _type() = default;
+#  define MOZ_COUNTED_DTOR_META(_type, _prefix, _postfix) \
+    _prefix ~_type() _postfix = default;
+#  define MOZ_COUNTED_DTOR_NESTED(_type, _nestedName) ~_type() = default;
+
+#endif /* NS_BUILD_REFCNT_LOGGING */
+
+#define MOZ_COUNTED_DTOR(_type) MOZ_COUNTED_DTOR_META(_type, , )
+#define MOZ_COUNTED_DTOR_OVERRIDE(_type) \
+  MOZ_COUNTED_DTOR_META(_type, , override)
+#define MOZ_COUNTED_DTOR_FINAL(_type) MOZ_COUNTED_DTOR_META(_type, , final)
+#define MOZ_COUNTED_DTOR_VIRTUAL(_type) MOZ_COUNTED_DTOR_META(_type, virtual, )
+
+// Support for ISupports classes which interact with cycle collector.
+
+#ifdef HAVE_64BIT_BUILD
+#  define NS_NUMBER_OF_FLAGS_IN_REFCNT 3
+#  define NS_IS_ON_MAINTHREAD (1 << 2)
+#else
+#  define NS_NUMBER_OF_FLAGS_IN_REFCNT 2
+#endif
+
+#define NS_IN_PURPLE_BUFFER (1 << 0)
+#define NS_IS_PURPLE (1 << 1)
+#define NS_REFCOUNT_CHANGE (1 << NS_NUMBER_OF_FLAGS_IN_REFCNT)
+#define NS_REFCOUNT_VALUE(_val) (_val >> NS_NUMBER_OF_FLAGS_IN_REFCNT)
+
+class nsCycleCollectingAutoRefCnt {
+ public:
+  typedef void (*Suspect)(void* aPtr, nsCycleCollectionParticipant* aCp,
+                          nsCycleCollectingAutoRefCnt* aRefCnt,
+                          bool* aShouldDelete);
+
+  nsCycleCollectingAutoRefCnt() : mRefCntAndFlags(0) {}
+
+  explicit nsCycleCollectingAutoRefCnt(uintptr_t aValue)
+      : mRefCntAndFlags(aValue << NS_NUMBER_OF_FLAGS_IN_REFCNT) {}
+
+  nsCycleCollectingAutoRefCnt(const nsCycleCollectingAutoRefCnt&) = delete;
+  void operator=(const nsCycleCollectingAutoRefCnt&) = delete;
+
+  MOZ_ALWAYS_INLINE uintptr_t incr(nsISupports* aOwner) {
+    return incr(aOwner, nullptr);
+  }
+
+  MOZ_ALWAYS_INLINE uintptr_t incr(void* aOwner,
+                                   nsCycleCollectionParticipant* aCp) {
+    mRefCntAndFlags += NS_REFCOUNT_CHANGE;
+    mRefCntAndFlags &= ~NS_IS_PURPLE;
+    // For incremental cycle collection, use the purple buffer to track objects
+    // that have been AddRef'd.
+    if (!IsInPurpleBuffer()) {
+      mRefCntAndFlags |= NS_IN_PURPLE_BUFFER;
+      // Refcount isn't zero, so Suspect won't delete anything.
+      MOZ_ASSERT(get() > 0);
+      NS_CycleCollectorSuspect3(aOwner, aCp, this, nullptr);
+    }
+    return NS_REFCOUNT_VALUE(mRefCntAndFlags);
+  }
+
+  MOZ_ALWAYS_INLINE void stabilizeForDeletion() {
+    // Set refcnt to 1 and mark us to be in the purple buffer.
+    // This way decr won't call suspect again.
+    mRefCntAndFlags = NS_REFCOUNT_CHANGE | NS_IN_PURPLE_BUFFER;
+  }
+
+  MOZ_ALWAYS_INLINE uintptr_t decr(nsISupports* aOwner,
+                                   bool* aShouldDelete = nullptr) {
+    return decr(aOwner, nullptr, aShouldDelete);
+  }
+
+  MOZ_ALWAYS_INLINE uintptr_t decr(void* aOwner,
+                                   nsCycleCollectionParticipant* aCp,
+                                   bool* aShouldDelete = nullptr) {
+    MOZ_ASSERT(get() > 0);
+    if (!IsInPurpleBuffer()) {
+      mRefCntAndFlags -= NS_REFCOUNT_CHANGE;
+      mRefCntAndFlags |= (NS_IN_PURPLE_BUFFER | NS_IS_PURPLE);
+      uintptr_t retval = NS_REFCOUNT_VALUE(mRefCntAndFlags);
+      // Suspect may delete 'aOwner' and 'this'!
+      NS_CycleCollectorSuspect3(aOwner, aCp, this, aShouldDelete);
+      return retval;
+    }
+    mRefCntAndFlags -= NS_REFCOUNT_CHANGE;
+    mRefCntAndFlags |= (NS_IN_PURPLE_BUFFER | NS_IS_PURPLE);
+    return NS_REFCOUNT_VALUE(mRefCntAndFlags);
+  }
+
+  MOZ_ALWAYS_INLINE void RemovePurple() {
+    MOZ_ASSERT(IsPurple(), "must be purple");
+    mRefCntAndFlags &= ~NS_IS_PURPLE;
+  }
+
+  MOZ_ALWAYS_INLINE void RemoveFromPurpleBuffer() {
+    MOZ_ASSERT(IsInPurpleBuffer());
+    mRefCntAndFlags &= ~(NS_IS_PURPLE | NS_IN_PURPLE_BUFFER);
+  }
+
+  MOZ_ALWAYS_INLINE bool IsPurple() const {
+    return !!(mRefCntAndFlags & NS_IS_PURPLE);
+  }
+
+  MOZ_ALWAYS_INLINE bool IsInPurpleBuffer() const {
+    return !!(mRefCntAndFlags & NS_IN_PURPLE_BUFFER);
+  }
+
+  // Cycle collected objects can only be used on a single thread, so if we ever
+  // see an object on the main thread, it will always be on the main thread.
+  // The cycle collector then uses this information to utilize faster nursery
+  // purple buffer on the main thread.
+  // The method works only on 64 bit systems.
+  MOZ_ALWAYS_INLINE void SetIsOnMainThread() {
+#ifdef HAVE_64BIT_BUILD
+    mRefCntAndFlags |= NS_IS_ON_MAINTHREAD;
+#endif
+  }
+
+#ifdef HAVE_64BIT_BUILD
+  // The NS_IS_ON_MAINTHREAD flag only exists on 64-bit builds.
+  MOZ_ALWAYS_INLINE bool IsOnMainThread() {
+    return !!(mRefCntAndFlags & NS_IS_ON_MAINTHREAD);
+  }
+#endif
+
+  MOZ_ALWAYS_INLINE nsrefcnt get() const {
+    return NS_REFCOUNT_VALUE(mRefCntAndFlags);
+  }
+
+  MOZ_ALWAYS_INLINE operator nsrefcnt() const { return get(); }
+
+ private:
+  uintptr_t mRefCntAndFlags;
+};
+
+class nsAutoRefCnt {
+ public:
+  nsAutoRefCnt() : mValue(0) {}
+  explicit nsAutoRefCnt(nsrefcnt aValue) : mValue(aValue) {}
+
+  nsAutoRefCnt(const nsAutoRefCnt&) = delete;
+  void operator=(const nsAutoRefCnt&) = delete;
+
+  // only support prefix increment/decrement
+  nsrefcnt operator++() { return ++mValue; }
+  nsrefcnt operator--() { return --mValue; }
+
+  nsrefcnt operator=(nsrefcnt aValue) { return (mValue = aValue); }
+  operator nsrefcnt() const { return mValue; }
+  nsrefcnt get() const { return mValue; }
+
+  static const bool isThreadSafe = false;
+
+ private:
+  nsrefcnt operator++(int) = delete;
+  nsrefcnt operator--(int) = delete;
+  nsrefcnt mValue;
+};
+
+namespace mozilla {
+class ThreadSafeAutoRefCnt {
+ public:
+  ThreadSafeAutoRefCnt() : mValue(0) {}
+  explicit ThreadSafeAutoRefCnt(nsrefcnt aValue) : mValue(aValue) {}
+
+  ThreadSafeAutoRefCnt(const ThreadSafeAutoRefCnt&) = delete;
+  void operator=(const ThreadSafeAutoRefCnt&) = delete;
+
+  // only support prefix increment/decrement
+  MOZ_ALWAYS_INLINE nsrefcnt operator++() {
+    // Memory synchronization is not required when incrementing a
+    // reference count.  The first increment of a reference count on a
+    // thread is not important, since the first use of the object on a
+    // thread can happen before it.  What is important is the transfer
+    // of the pointer to that thread, which may happen prior to the
+    // first increment on that thread.  The necessary memory
+    // synchronization is done by the mechanism that transfers the
+    // pointer between threads.
+    return mValue.fetch_add(1, std::memory_order_relaxed) + 1;
+  }
+  MOZ_ALWAYS_INLINE nsrefcnt operator--() {
+    // Since this may be the last release on this thread, we need
+    // release semantics so that prior writes on this thread are visible
+    // to the thread that destroys the object when it reads mValue with
+    // acquire semantics.
+    nsrefcnt result = mValue.fetch_sub(1, std::memory_order_release) - 1;
+    if (result == 0) {
+      // We're going to destroy the object on this thread, so we need
+      // acquire semantics to synchronize with the memory released by
+      // the last release on other threads, that is, to ensure that
+      // writes prior to that release are now visible on this thread.
+#ifdef MOZ_TSAN
+      // TSan doesn't understand std::atomic_thread_fence, so in order
+      // to avoid a false positive for every time a refcounted object
+      // is deleted, we replace the fence with an atomic operation.
+      mValue.load(std::memory_order_acquire);
+#else
+      std::atomic_thread_fence(std::memory_order_acquire);
+#endif
+    }
+    return result;
+  }
+
+  MOZ_ALWAYS_INLINE nsrefcnt operator=(nsrefcnt aValue) {
+    // Use release semantics since we're not sure what the caller is
+    // doing.
+    mValue.store(aValue, std::memory_order_release);
+    return aValue;
+  }
+  MOZ_ALWAYS_INLINE operator nsrefcnt() const { return get(); }
+  MOZ_ALWAYS_INLINE nsrefcnt get() const {
+    // Use acquire semantics since we're not sure what the caller is
+    // doing.
+    return mValue.load(std::memory_order_acquire);
+  }
+
+  static const bool isThreadSafe = true;
+
+ private:
+  nsrefcnt operator++(int) = delete;
+  nsrefcnt operator--(int) = delete;
+  std::atomic<nsrefcnt> mValue;
+};
+
+namespace detail {
+
+// Type trait indicating whether a given XPCOM interface class may only be
+// implemented by types with threadsafe refcounts. This is specialized for
+// classes with the `rust_sync` annotation within XPIDL-generated header files,
+// and checked within macro-generated QueryInterface implementations.
+template <typename T>
+class InterfaceNeedsThreadSafeRefCnt : public std::false_type {};
+
+}
+}  // namespace mozilla
+
+///////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Declare the reference count variable and the implementations of the
+ * AddRef and QueryInterface methods.
+ */
+
+#define NS_DECL_ISUPPORTS                                                 \
+ public:                                                                  \
+  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override; \
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) override;             \
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) override;            \
+  using HasThreadSafeRefCnt = std::false_type;                            \
+                                                                          \
+ protected:                                                               \
+  nsAutoRefCnt mRefCnt;                                                   \
+  NS_DECL_OWNINGTHREAD                                                    \
+ public:
+
+#define NS_DECL_ISUPPORTS_ONEVENTTARGET                                   \
+ public:                                                                  \
+  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override; \
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) override;             \
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) override;            \
+  using HasThreadSafeRefCnt = std::false_type;                            \
+                                                                          \
+ protected:                                                               \
+  nsAutoRefCnt mRefCnt;                                                   \
+  NS_DECL_OWNINGEVENTTARGET                                               \
+ public:
+
+#define NS_DECL_THREADSAFE_ISUPPORTS                                      \
+ public:                                                                  \
+  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override; \
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) override;             \
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) override;            \
+  using HasThreadSafeRefCnt = std::true_type;                             \
+                                                                          \
+ protected:                                                               \
+  ::mozilla::ThreadSafeAutoRefCnt mRefCnt;                                \
+  NS_DECL_OWNINGTHREAD                                                    \
+ public:
+
+#define NS_DECL_CYCLE_COLLECTING_ISUPPORTS          \
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS_META(override) \
+  NS_IMETHOD_(void) DeleteCycleCollectable(void);   \
+                                                    \
+ public:
+
+#define NS_DECL_CYCLE_COLLECTING_ISUPPORTS_FINAL  \
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS_META(final)  \
+  NS_IMETHOD_(void) DeleteCycleCollectable(void); \
+                                                  \
+ public:
+
+#define NS_DECL_CYCLE_COLLECTING_ISUPPORTS_META(...)                         \
+ public:                                                                     \
+  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) __VA_ARGS__; \
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) __VA_ARGS__;             \
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) __VA_ARGS__;            \
+  using HasThreadSafeRefCnt = std::false_type;                               \
+                                                                             \
+ protected:                                                                  \
+  nsCycleCollectingAutoRefCnt mRefCnt;                                       \
+  NS_DECL_OWNINGTHREAD                                                       \
+ public:
+
+///////////////////////////////////////////////////////////////////////////////
+
+/*
+ * Implementation of AddRef and Release for non-nsISupports (ie "native")
+ * cycle-collected classes that use the purple buffer to avoid leaks.
+ */
+
+#define NS_IMPL_CC_NATIVE_ADDREF_BODY(_class)                                 \
+  MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(_class)                                  \
+  MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");                        \
+  NS_ASSERT_OWNINGTHREAD(_class);                                             \
+  nsrefcnt count =                                                            \
+      mRefCnt.incr(static_cast<void*>(this),                                  \
+                   _class::NS_CYCLE_COLLECTION_INNERCLASS::GetParticipant()); \
+  NS_LOG_ADDREF(this, count, #_class, sizeof(*this));                         \
+  return count;
+
+#define NS_IMPL_CC_NATIVE_RELEASE_BODY(_class)                                \
+  MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                            \
+  NS_ASSERT_OWNINGTHREAD(_class);                                             \
+  nsrefcnt count =                                                            \
+      mRefCnt.decr(static_cast<void*>(this),                                  \
+                   _class::NS_CYCLE_COLLECTION_INNERCLASS::GetParticipant()); \
+  NS_LOG_RELEASE(this, count, #_class);                                       \
+  return count;
+
+#define NS_IMPL_CYCLE_COLLECTING_NATIVE_ADDREF(_class)       \
+  NS_METHOD_(MozExternalRefCountType) _class::AddRef(void) { \
+    NS_IMPL_CC_NATIVE_ADDREF_BODY(_class)                    \
+  }
+
+#define NS_IMPL_CYCLE_COLLECTING_NATIVE_RELEASE_WITH_LAST_RELEASE(_class,      \
+                                                                  _last)       \
+  NS_METHOD_(MozExternalRefCountType) _class::Release(void) {                  \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                           \
+    NS_ASSERT_OWNINGTHREAD(_class);                                            \
+    bool shouldDelete = false;                                                 \
+    nsrefcnt count =                                                           \
+        mRefCnt.decr(static_cast<void*>(this),                                 \
+                     _class::NS_CYCLE_COLLECTION_INNERCLASS::GetParticipant(), \
+                     &shouldDelete);                                           \
+    NS_LOG_RELEASE(this, count, #_class);                                      \
+    if (count == 0) {                                                          \
+      mRefCnt.incr(static_cast<void*>(this),                                   \
+                   _class::NS_CYCLE_COLLECTION_INNERCLASS::GetParticipant());  \
+      _last;                                                                   \
+      mRefCnt.decr(static_cast<void*>(this),                                   \
+                   _class::NS_CYCLE_COLLECTION_INNERCLASS::GetParticipant());  \
+      if (shouldDelete) {                                                      \
+        mRefCnt.stabilizeForDeletion();                                        \
+        DeleteCycleCollectable();                                              \
+      }                                                                        \
+    }                                                                          \
+    return count;                                                              \
+  }
+
+#define NS_IMPL_CYCLE_COLLECTING_NATIVE_RELEASE(_class)       \
+  NS_METHOD_(MozExternalRefCountType) _class::Release(void) { \
+    NS_IMPL_CC_NATIVE_RELEASE_BODY(_class)                    \
+  }
+
+#define NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(_class) \
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING_META(_class, NS_METHOD_)
+
+#define NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING_VIRTUAL(_class) \
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING_META(_class, NS_IMETHOD_)
+
+#define NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING_INHERITED(_class)  \
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING_META(_class, NS_METHOD_, \
+                                                          override)
+
+#define NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING_META(_class, _decl, \
+                                                                ...)           \
+ public:                                                                       \
+  _decl(MozExternalRefCountType) AddRef(void) __VA_ARGS__{                     \
+      NS_IMPL_CC_NATIVE_ADDREF_BODY(_class)} _decl(MozExternalRefCountType)    \
+      Release(void) __VA_ARGS__ {                                              \
+    NS_IMPL_CC_NATIVE_RELEASE_BODY(_class)                                     \
+  }                                                                            \
+  using HasThreadSafeRefCnt = std::false_type;                                 \
+                                                                               \
+ protected:                                                                    \
+  nsCycleCollectingAutoRefCnt mRefCnt;                                         \
+  NS_DECL_OWNINGTHREAD                                                         \
+ public:
+
+///////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Use this macro to declare and implement the AddRef & Release methods for a
+ * given non-XPCOM <i>_class</i>.
+ *
+ * @param _class The name of the class implementing the method
+ * @param _destroy A statement that is executed when the object's
+ *   refcount drops to zero.
+ * @param _decl Name of the macro to be used for the return type of the
+ *   AddRef & Release methods (typically NS_IMETHOD_ or NS_METHOD_).
+ * @param optional override Mark the AddRef & Release methods as overrides.
+ */
+#define NS_INLINE_DECL_REFCOUNTING_META(_class, _decl, _destroy, _owning, ...) \
+ public:                                                                       \
+  _decl(MozExternalRefCountType) AddRef(void) __VA_ARGS__ {                    \
+    MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(_class)                                 \
+    MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");                       \
+    NS_ASSERT_OWNINGTHREAD(_class);                                            \
+    ++mRefCnt;                                                                 \
+    NS_LOG_ADDREF(this, mRefCnt, #_class, sizeof(*this));                      \
+    return mRefCnt;                                                            \
+  }                                                                            \
+  _decl(MozExternalRefCountType) Release(void) __VA_ARGS__ {                   \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                           \
+    NS_ASSERT_OWNINGTHREAD(_class);                                            \
+    --mRefCnt;                                                                 \
+    NS_LOG_RELEASE(this, mRefCnt, #_class);                                    \
+    if (mRefCnt == 0) {                                                        \
+      mRefCnt = 1; /* stabilize */                                             \
+      _destroy;                                                                \
+      return 0;                                                                \
+    }                                                                          \
+    return mRefCnt;                                                            \
+  }                                                                            \
+  using HasThreadSafeRefCnt = std::false_type;                                 \
+                                                                               \
+ protected:                                                                    \
+  nsAutoRefCnt mRefCnt;                                                        \
+  _owning public:
+
+/**
+ * Use this macro to declare and implement the AddRef & Release methods for a
+ * given non-XPCOM <i>_class</i>.
+ *
+ * @param _class The name of the class implementing the method
+ * @param _destroy A statement that is executed when the object's
+ *   refcount drops to zero.
+ * @param optional override Mark the AddRef & Release methods as overrides.
+ */
+#define NS_INLINE_DECL_REFCOUNTING_WITH_DESTROY(_class, _destroy, ...) \
+  NS_INLINE_DECL_REFCOUNTING_META(_class, NS_METHOD_, _destroy,        \
+                                  NS_DECL_OWNINGTHREAD, __VA_ARGS__)
+
+/**
+ * Like NS_INLINE_DECL_REFCOUNTING_WITH_DESTROY with AddRef & Release declared
+ * virtual.
+ */
+#define NS_INLINE_DECL_VIRTUAL_REFCOUNTING_WITH_DESTROY(_class, _destroy, ...) \
+  NS_INLINE_DECL_REFCOUNTING_META(_class, NS_IMETHOD_, _destroy,               \
+                                  NS_DECL_OWNINGTHREAD, __VA_ARGS__)
+
+/**
+ * Use this macro to declare and implement the AddRef & Release methods for a
+ * given non-XPCOM <i>_class</i>.
+ *
+ * @param _class The name of the class implementing the method
+ * @param optional override Mark the AddRef & Release methods as overrides.
+ */
+#define NS_INLINE_DECL_REFCOUNTING(_class, ...) \
+  NS_INLINE_DECL_REFCOUNTING_WITH_DESTROY(_class, delete (this), __VA_ARGS__)
+
+/**
+ * Like NS_INLINE_DECL_REFCOUNTING, however the thread safety check will work
+ * with any nsISerialEventTarget. This is a workaround until bug 1648031 is
+ * properly resolved. Once this is done, it will be possible to use
+ * NS_INLINE_DECL_REFCOUNTING under all circumstances.
+ */
+#define NS_INLINE_DECL_REFCOUNTING_ONEVENTTARGET(_class, ...)        \
+  NS_INLINE_DECL_REFCOUNTING_META(_class, NS_METHOD_, delete (this), \
+                                  NS_DECL_OWNINGEVENTTARGET, __VA_ARGS__)
+
+#define NS_INLINE_DECL_THREADSAFE_REFCOUNTING_META(_class, _decl, _destroy, \
+                                                   ...)                     \
+ public:                                                                    \
+  _decl(MozExternalRefCountType) AddRef(void) __VA_ARGS__ {                 \
+    MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(_class)                              \
+    MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");                    \
+    nsrefcnt count = ++mRefCnt;                                             \
+    NS_LOG_ADDREF(this, count, #_class, sizeof(*this));                     \
+    return (nsrefcnt)count;                                                 \
+  }                                                                         \
+  _decl(MozExternalRefCountType) Release(void) __VA_ARGS__ {                \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                        \
+    nsrefcnt count = --mRefCnt;                                             \
+    NS_LOG_RELEASE(this, count, #_class);                                   \
+    if (count == 0) {                                                       \
+      _destroy;                                                             \
+      return 0;                                                             \
+    }                                                                       \
+    return count;                                                           \
+  }                                                                         \
+  using HasThreadSafeRefCnt = std::true_type;                               \
+                                                                            \
+ protected:                                                                 \
+  ::mozilla::ThreadSafeAutoRefCnt mRefCnt;                                  \
+                                                                            \
+ public:
+
+/**
+ * Use this macro to declare and implement the AddRef & Release methods for a
+ * given non-XPCOM <i>_class</i> in a threadsafe manner.
+ *
+ * DOES NOT DO REFCOUNT STABILIZATION!
+ *
+ * @param _class The name of the class implementing the method
+ * @param _destroy A statement that is executed when the object's
+ *   refcount drops to zero.
+ * @param optional override Mark the AddRef & Release methods as overrides.
+ */
+#define NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DESTROY(_class, _destroy, \
+                                                           ...)              \
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING_META(_class, NS_METHOD_, _destroy,   \
+                                             __VA_ARGS__)
+
+/**
+ * Like NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DESTROY with AddRef & Release
+ * declared virtual.
+ */
+#define NS_INLINE_DECL_THREADSAFE_VIRTUAL_REFCOUNTING_WITH_DESTROY(         \
+    _class, _destroy, ...)                                                  \
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING_META(_class, NS_IMETHOD_, _destroy, \
+                                             __VA_ARGS__)
+
+/**
+ * Use this macro to declare and implement the AddRef & Release methods for a
+ * given non-XPCOM <i>_class</i> in a threadsafe manner.
+ *
+ * DOES NOT DO REFCOUNT STABILIZATION!
+ *
+ * @param _class The name of the class implementing the method
+ * @param optional override Mark the AddRef & Release methods as overrides.
+ */
+#define NS_INLINE_DECL_THREADSAFE_REFCOUNTING(_class, ...)                  \
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DESTROY(_class, delete (this), \
+                                                     __VA_ARGS__)
+
+/**
+ * Like NS_INLINE_DECL_THREADSAFE_REFCOUNTING with AddRef & Release declared
+ * virtual.
+ */
+#define NS_INLINE_DECL_THREADSAFE_VIRTUAL_REFCOUNTING(_class, ...) \
+  NS_INLINE_DECL_THREADSAFE_VIRTUAL_REFCOUNTING_WITH_DESTROY(      \
+      _class, delete (this), __VA_ARGS__)
+
+#if !defined(XPCOM_GLUE_AVOID_NSPR)
+class nsISerialEventTarget;
+namespace mozilla {
+// Forward-declare `GetMainThreadSerialEventTarget`, as `nsISupportsImpl.h`
+// cannot include `nsThreadUtils.h`.
+nsISerialEventTarget* GetMainThreadSerialEventTarget();
+
+namespace detail {
+using DeleteVoidFunction = void(void*);
+void ProxyDeleteVoid(const char* aRunnableName,
+                     nsISerialEventTarget* aEventTarget, void* aSelf,
+                     DeleteVoidFunction* aDeleteFunc);
+}  // namespace detail
+}  // namespace mozilla
+
+/**
+ * Helper for _WITH_DELETE_ON_EVENT_TARGET threadsafe refcounting macros which
+ * provides an implementation of `_destroy`
+ */
+#  define NS_PROXY_DELETE_TO_EVENT_TARGET(_class, _target) \
+    ::mozilla::detail::ProxyDeleteVoid(                    \
+        "ProxyDelete " #_class, _target, this,             \
+        [](void* self) { delete static_cast<_class*>(self); })
+
+/**
+ * Use this macro to declare and implement the AddRef & Release methods for a
+ * given non-XPCOM <i>_class</i> in a threadsafe manner, ensuring the
+ * destructor runs on a specific nsISerialEventTarget.
+ *
+ * DOES NOT DO REFCOUNT STABILIZATION!
+ *
+ * @param _class The name of the class implementing the method
+ * @param _target nsISerialEventTarget to run the class's destructor on
+ * @param optional override Mark the AddRef & Release methods as overrides
+ */
+#  define NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DELETE_ON_EVENT_TARGET( \
+      _class, _target, ...)                                                  \
+    NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DESTROY(                      \
+        _class, NS_PROXY_DELETE_TO_EVENT_TARGET(_class, _target), __VA_ARGS__)
+
+/**
+ * Use this macro to declare and implement the AddRef & Release methods for a
+ * given non-XPCOM <i>_class</i> in a threadsafe manner, ensuring the
+ * destructor runs on the main thread.
+ *
+ * DOES NOT DO REFCOUNT STABILIZATION!
+ *
+ * @param _class The name of the class implementing the method
+ * @param optional override Mark the AddRef & Release methods as overrides
+ */
+#  define NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DELETE_ON_MAIN_THREAD( \
+      _class, ...)                                                          \
+    NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DELETE_ON_EVENT_TARGET(      \
+        _class, ::mozilla::GetMainThreadSerialEventTarget(), __VA_ARGS__)
+#endif
+
+/**
+ * Use this macro in interface classes that you want to be able to reference
+ * using RefPtr, but don't want to provide a refcounting implemenation. The
+ * refcounting implementation can be provided by concrete subclasses that
+ * implement the interface.
+ */
+#define NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING           \
+ public:                                                  \
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) = 0;  \
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) = 0; \
+                                                          \
+ public:
+
+/**
+ * Use this macro to implement the AddRef method for a given <i>_class</i>
+ * @param _class The name of the class implementing the method
+ * @param _name The class name to be passed to XPCOM leak checking
+ */
+#define NS_IMPL_NAMED_ADDREF(_class, _name)                      \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::AddRef(void) { \
+    MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(_class)                   \
+    MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");         \
+    MOZ_ASSERT(_name != nullptr, "Must specify a name");         \
+    if (!mRefCnt.isThreadSafe) NS_ASSERT_OWNINGTHREAD(_class);   \
+    nsrefcnt count = ++mRefCnt;                                  \
+    NS_LOG_ADDREF(this, count, _name, sizeof(*this));            \
+    return count;                                                \
+  }
+
+/**
+ * Use this macro to implement the AddRef method for a given <i>_class</i>
+ * @param _class The name of the class implementing the method
+ */
+#define NS_IMPL_ADDREF(_class) NS_IMPL_NAMED_ADDREF(_class, #_class)
+
+/**
+ * Use this macro to implement the AddRef method for a given <i>_class</i>
+ * implemented as a wholly owned aggregated object intended to implement
+ * interface(s) for its owner
+ * @param _class The name of the class implementing the method
+ * @param _aggregator the owning/containing object
+ */
+#define NS_IMPL_ADDREF_USING_AGGREGATOR(_class, _aggregator)     \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::AddRef(void) { \
+    MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(_class)                   \
+    MOZ_ASSERT(_aggregator, "null aggregator");                  \
+    return (_aggregator)->AddRef();                              \
+  }
+
+// We decrement the refcnt before logging the actual release, but when logging
+// named things, accessing the name may not be valid after the refcnt
+// decrement, because the object may have been destroyed on a different thread.
+// Use this macro to ensure that we have a local copy of the name prior to
+// the refcnt decrement.  (We use a macro to make absolutely sure the name
+// isn't loaded in builds where it wouldn't be used.)
+#ifdef NS_BUILD_REFCNT_LOGGING
+#  define NS_LOAD_NAME_BEFORE_RELEASE(localname, _name) \
+    const char* const localname = _name
+#else
+#  define NS_LOAD_NAME_BEFORE_RELEASE(localname, _name)
+#endif
+
+/**
+ * Use this macro to implement the Release method for a given
+ * <i>_class</i>.
+ * @param _class The name of the class implementing the method
+ * @param _name The class name to be passed to XPCOM leak checking
+ * @param _destroy A statement that is executed when the object's
+ *   refcount drops to zero.
+ *
+ * For example,
+ *
+ *   NS_IMPL_RELEASE_WITH_DESTROY(Foo, "Foo", Destroy(this))
+ *
+ * will cause
+ *
+ *   Destroy(this);
+ *
+ * to be invoked when the object's refcount drops to zero. This
+ * allows for arbitrary teardown activity to occur (e.g., deallocation
+ * of object allocated with placement new).
+ */
+#define NS_IMPL_NAMED_RELEASE_WITH_DESTROY(_class, _name, _destroy) \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::Release(void) {   \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                \
+    MOZ_ASSERT(_name != nullptr, "Must specify a name");            \
+    if (!mRefCnt.isThreadSafe) NS_ASSERT_OWNINGTHREAD(_class);      \
+    NS_LOAD_NAME_BEFORE_RELEASE(nametmp, _name);                    \
+    nsrefcnt count = --mRefCnt;                                     \
+    NS_LOG_RELEASE(this, count, nametmp);                           \
+    if (count == 0) {                                               \
+      mRefCnt = 1; /* stabilize */                                  \
+      _destroy;                                                     \
+      return 0;                                                     \
+    }                                                               \
+    return count;                                                   \
+  }
+
+#define NS_IMPL_RELEASE_WITH_DESTROY(_class, _destroy) \
+  NS_IMPL_NAMED_RELEASE_WITH_DESTROY(_class, #_class, _destroy)
+
+/**
+ * Use this macro to implement the Release method for a given <i>_class</i>
+ * @param _class The name of the class implementing the method
+ *
+ * A note on the 'stabilization' of the refcnt to one. At that point,
+ * the object's refcount will have gone to zero. The object's
+ * destructor may trigger code that attempts to QueryInterface() and
+ * Release() 'this' again. Doing so will temporarily increment and
+ * decrement the refcount. (Only a logic error would make one try to
+ * keep a permanent hold on 'this'.)  To prevent re-entering the
+ * destructor, we make sure that no balanced refcounting can return
+ * the refcount to |0|.
+ */
+#define NS_IMPL_RELEASE(_class) \
+  NS_IMPL_RELEASE_WITH_DESTROY(_class, delete (this))
+
+#define NS_IMPL_NAMED_RELEASE(_class, _name) \
+  NS_IMPL_NAMED_RELEASE_WITH_DESTROY(_class, _name, delete (this))
+
+/**
+ * Use this macro to implement the Release method for a given <i>_class</i>
+ * implemented as a wholly owned aggregated object intended to implement
+ * interface(s) for its owner
+ * @param _class The name of the class implementing the method
+ * @param _aggregator the owning/containing object
+ */
+#define NS_IMPL_RELEASE_USING_AGGREGATOR(_class, _aggregator)     \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::Release(void) { \
+    MOZ_ASSERT(_aggregator, "null aggregator");                   \
+    return (_aggregator)->Release();                              \
+  }
+
+#define NS_IMPL_CYCLE_COLLECTING_ADDREF(_class)                              \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::AddRef(void) {             \
+    MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(_class)                               \
+    MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");                     \
+    NS_ASSERT_OWNINGTHREAD(_class);                                          \
+    nsISupports* base = NS_CYCLE_COLLECTION_CLASSNAME(_class)::Upcast(this); \
+    nsrefcnt count = mRefCnt.incr(base);                                     \
+    NS_LOG_ADDREF(this, count, #_class, sizeof(*this));                      \
+    return count;                                                            \
+  }
+
+#define NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_DESTROY(_class, _destroy)      \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::Release(void) {            \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                         \
+    NS_ASSERT_OWNINGTHREAD(_class);                                          \
+    nsISupports* base = NS_CYCLE_COLLECTION_CLASSNAME(_class)::Upcast(this); \
+    nsrefcnt count = mRefCnt.decr(base);                                     \
+    NS_LOG_RELEASE(this, count, #_class);                                    \
+    return count;                                                            \
+  }                                                                          \
+  NS_IMETHODIMP_(void) _class::DeleteCycleCollectable(void) { _destroy; }
+
+#define NS_IMPL_CYCLE_COLLECTING_RELEASE(_class) \
+  NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_DESTROY(_class, delete (this))
+
+// _LAST_RELEASE can be useful when certain resources should be released
+// as soon as we know the object will be deleted.
+#define NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE(_class, _last)    \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::Release(void) {            \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                         \
+    NS_ASSERT_OWNINGTHREAD(_class);                                          \
+    bool shouldDelete = false;                                               \
+    nsISupports* base = NS_CYCLE_COLLECTION_CLASSNAME(_class)::Upcast(this); \
+    nsrefcnt count = mRefCnt.decr(base, &shouldDelete);                      \
+    NS_LOG_RELEASE(this, count, #_class);                                    \
+    if (count == 0) {                                                        \
+      mRefCnt.incr(base);                                                    \
+      _last;                                                                 \
+      mRefCnt.decr(base);                                                    \
+      if (shouldDelete) {                                                    \
+        mRefCnt.stabilizeForDeletion();                                      \
+        DeleteCycleCollectable();                                            \
+      }                                                                      \
+    }                                                                        \
+    return count;                                                            \
+  }                                                                          \
+  NS_IMETHODIMP_(void) _class::DeleteCycleCollectable(void) { delete this; }
+
+// This macro is same as NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE
+// except it doesn't have DeleteCycleCollectable.
+#define NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE_AND_DESTROY(      \
+    _class, _last, _destroy)                                                 \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::Release(void) {            \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                         \
+    NS_ASSERT_OWNINGTHREAD(_class);                                          \
+    bool shouldDelete = false;                                               \
+    nsISupports* base = NS_CYCLE_COLLECTION_CLASSNAME(_class)::Upcast(this); \
+    nsrefcnt count = mRefCnt.decr(base, &shouldDelete);                      \
+    NS_LOG_RELEASE(this, count, #_class);                                    \
+    if (count == 0) {                                                        \
+      mRefCnt.incr(base);                                                    \
+      _last;                                                                 \
+      mRefCnt.decr(base);                                                    \
+      if (shouldDelete) {                                                    \
+        mRefCnt.stabilizeForDeletion();                                      \
+        DeleteCycleCollectable();                                            \
+      }                                                                      \
+    }                                                                        \
+    return count;                                                            \
+  }                                                                          \
+  NS_IMETHODIMP_(void) _class::DeleteCycleCollectable(void) { _destroy; }
+
+// _WITH_INTERRUPTABLE_LAST_RELEASE can be useful when certain resources
+// should be released as soon as we know the object will be deleted and the
+// instance may be cached for reuse.
+// _last is performed for cleaning up its resources.  Then, _maybeInterrupt is
+// tested and when it returns true, this stops deleting the instance.
+// (Note that it's not allowed to grab the instance with nsCOMPtr or RefPtr
+// during _last is performed.)
+// Therefore, when _maybeInterrupt returns true, the instance has to be grabbed
+// by nsCOMPtr or RefPtr.
+#define NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_INTERRUPTABLE_LAST_RELEASE(    \
+    _class, _last, _maybeInterrupt)                                          \
+  NS_IMETHODIMP_(MozExternalRefCountType) _class::Release(void) {            \
+    MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");                         \
+    NS_ASSERT_OWNINGTHREAD(_class);                                          \
+    bool shouldDelete = false;                                               \
+    nsISupports* base = NS_CYCLE_COLLECTION_CLASSNAME(_class)::Upcast(this); \
+    nsrefcnt count = mRefCnt.decr(base, &shouldDelete);                      \
+    NS_LOG_RELEASE(this, count, #_class);                                    \
+    if (count == 0) {                                                        \
+      mRefCnt.incr(base);                                                    \
+      _last;                                                                 \
+      mRefCnt.decr(base);                                                    \
+      if (_maybeInterrupt) {                                                 \
+        MOZ_ASSERT(mRefCnt.get() > 0);                                       \
+        return mRefCnt.get();                                                \
+      }                                                                      \
+      if (shouldDelete) {                                                    \
+        mRefCnt.stabilizeForDeletion();                                      \
+        DeleteCycleCollectable();                                            \
+      }                                                                      \
+    }                                                                        \
+    return count;                                                            \
+  }                                                                          \
+  NS_IMETHODIMP_(void) _class::DeleteCycleCollectable(void) { delete this; }
+
+///////////////////////////////////////////////////////////////////////////////
+
+namespace mozilla::detail {
+
+// Helper which is roughly equivalent to NS_GET_IID, which also performs static
+// assertions that `Class` is allowed to implement the given XPCOM interface.
+//
+// These assertions are done like this to allow them to be used within the
+// `NS_INTERFACE_TABLE_ENTRY` macro, though they are also used in
+// `NS_IMPL_QUERY_BODY`.
+template <typename Class, typename Interface>
+constexpr const nsIID& GetImplementedIID() {
+  if constexpr (mozilla::detail::InterfaceNeedsThreadSafeRefCnt<
+                    Interface>::value) {
+    static_assert(Class::HasThreadSafeRefCnt::value,
+                  "Cannot implement a threadsafe interface with "
+                  "non-threadsafe refcounting!");
+  }
+  return NS_GET_TEMPLATE_IID(Interface);
+}
+
+template <typename Class, typename Interface>
+constexpr const nsIID& kImplementedIID = GetImplementedIID<Class, Interface>();
+
+}
+
+/**
+ * There are two ways of implementing QueryInterface, and we use both:
+ *
+ * Table-driven QueryInterface uses a static table of IID->offset mappings
+ * and a shared helper function. Using it tends to reduce codesize and improve
+ * runtime performance (due to processor cache hits).
+ *
+ * Macro-driven QueryInterface generates a QueryInterface function directly
+ * using common macros. This is necessary if special QueryInterface features
+ * are being used (such as tearoffs and conditional interfaces).
+ *
+ * These methods can be combined into a table-driven function call followed
+ * by custom code for tearoffs and conditionals.
+ */
+
+struct QITableEntry {
+  const nsIID* iid;  // null indicates end of the QITableEntry array
+  int32_t offset;
+};
+
+nsresult NS_FASTCALL NS_TableDrivenQI(void* aThis, REFNSIID aIID,
+                                      void** aInstancePtr,
+                                      const QITableEntry* aEntries);
+
+/**
+ * Implement table-driven queryinterface
+ */
+
+#define NS_INTERFACE_TABLE_HEAD(_class)                                      \
+  NS_IMETHODIMP _class::QueryInterface(REFNSIID aIID, void** aInstancePtr) { \
+    NS_ASSERTION(aInstancePtr,                                               \
+                 "QueryInterface requires a non-NULL destination!");         \
+    nsresult rv = NS_ERROR_FAILURE;
+
+#define NS_INTERFACE_TABLE_BEGIN static const QITableEntry table[] = {
+#define NS_INTERFACE_TABLE_ENTRY(_class, _interface)                        \
+  {&mozilla::detail::kImplementedIID<_class, _interface>,                   \
+   int32_t(                                                                 \
+       reinterpret_cast<char*>(static_cast<_interface*>((_class*)0x1000)) - \
+       reinterpret_cast<char*>((_class*)0x1000))},
+
+#define NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, _interface, _implClass) \
+  {&mozilla::detail::kImplementedIID<_class, _interface>,                  \
+   int32_t(reinterpret_cast<char*>(static_cast<_interface*>(               \
+               static_cast<_implClass*>((_class*)0x1000))) -               \
+           reinterpret_cast<char*>((_class*)0x1000))},
+
+/*
+ * XXX: we want to use mozilla::ArrayLength (or equivalent,
+ * MOZ_ARRAY_LENGTH) in this condition, but some versions of GCC don't
+ * see that the static_assert condition is actually constant in those
+ * cases, even with constexpr support (?).
+ */
+#define NS_INTERFACE_TABLE_END_WITH_PTR(_ptr)           \
+  { nullptr, 0 }                                        \
+  }                                                     \
+  ;                                                     \
+  static_assert((sizeof(table) / sizeof(table[0])) > 1, \
+                "need at least 1 interface");           \
+  rv = NS_TableDrivenQI(static_cast<void*>(_ptr), aIID, aInstancePtr, table);
+
+#define NS_INTERFACE_TABLE_END    \
+  NS_INTERFACE_TABLE_END_WITH_PTR \
+  (this)
+
+#define NS_INTERFACE_TABLE_TAIL \
+  return rv;                    \
+  }
+
+#define NS_INTERFACE_TABLE_TAIL_INHERITING(_baseclass)   \
+  if (NS_SUCCEEDED(rv)) return rv;                       \
+  return _baseclass::QueryInterface(aIID, aInstancePtr); \
+  }
+
+#define NS_INTERFACE_TABLE_TAIL_USING_AGGREGATOR(_aggregator) \
+  if (NS_SUCCEEDED(rv)) return rv;                            \
+  NS_ASSERTION(_aggregator, "null aggregator");               \
+  return _aggregator->QueryInterface(aIID, aInstancePtr)      \
+  }
+
+/**
+ * This implements query interface with two assumptions: First, the
+ * class in question implements nsISupports and its own interface and
+ * nothing else. Second, the implementation of the class's primary
+ * inheritance chain leads to its own interface.
+ *
+ * @param _class The name of the class implementing the method
+ * @param _classiiddef The name of the #define symbol that defines the IID
+ * for the class (e.g. NS_ISUPPORTS_IID)
+ */
+
+#define NS_IMPL_QUERY_HEAD(_class)                                           \
+  NS_IMETHODIMP _class::QueryInterface(REFNSIID aIID, void** aInstancePtr) { \
+    NS_ASSERTION(aInstancePtr,                                               \
+                 "QueryInterface requires a non-NULL destination!");         \
+    nsISupports* foundInterface;
+
+#define NS_IMPL_QUERY_BODY_IID(_interface)                                   \
+  mozilla::detail::kImplementedIID<std::remove_reference_t<decltype(*this)>, \
+                                   _interface>
+
+#define NS_IMPL_QUERY_BODY(_interface)                 \
+  if (aIID.Equals(NS_IMPL_QUERY_BODY_IID(_interface))) \
+    foundInterface = static_cast<_interface*>(this);   \
+  else
+
+#define NS_IMPL_QUERY_BODY_CONDITIONAL(_interface, condition)         \
+  if ((condition) && aIID.Equals(NS_IMPL_QUERY_BODY_IID(_interface))) \
+    foundInterface = static_cast<_interface*>(this);                  \
+  else
+
+#define NS_IMPL_QUERY_BODY_AMBIGUOUS(_interface, _implClass)                   \
+  if (aIID.Equals(NS_IMPL_QUERY_BODY_IID(_interface)))                         \
+    foundInterface = static_cast<_interface*>(static_cast<_implClass*>(this)); \
+  else
+
+// Use this for querying to concrete class types which cannot be unambiguously
+// cast to nsISupports. See also nsQueryObject.h.
+#define NS_IMPL_QUERY_BODY_CONCRETE(_class)                       \
+  if (aIID.Equals(NS_IMPL_QUERY_BODY_IID(_class))) {              \
+    *aInstancePtr = do_AddRef(static_cast<_class*>(this)).take(); \
+    return NS_OK;                                                 \
+  } else
+
+#define NS_IMPL_QUERY_BODY_AGGREGATED(_interface, _aggregate) \
+  if (aIID.Equals(NS_IMPL_QUERY_BODY_IID(_interface)))        \
+    foundInterface = static_cast<_interface*>(_aggregate);    \
+  else
+
+#define NS_IMPL_QUERY_TAIL_GUTS                                      \
+  foundInterface = 0;                                                \
+  nsresult status;                                                   \
+  if (!foundInterface) {                                             \
+    /* nsISupports should be handled by this point. If not, fail. */ \
+    MOZ_ASSERT(!aIID.Equals(NS_GET_IID(nsISupports)));               \
+    status = NS_NOINTERFACE;                                         \
+  } else {                                                           \
+    NS_ADDREF(foundInterface);                                       \
+    status = NS_OK;                                                  \
+  }                                                                  \
+  *aInstancePtr = foundInterface;                                    \
+  return status;                                                     \
+  }
+
+#define NS_IMPL_QUERY_TAIL_INHERITING(_baseclass)                       \
+  foundInterface = 0;                                                   \
+  nsresult status;                                                      \
+  if (!foundInterface)                                                  \
+    status = _baseclass::QueryInterface(aIID, (void**)&foundInterface); \
+  else {                                                                \
+    NS_ADDREF(foundInterface);                                          \
+    status = NS_OK;                                                     \
+  }                                                                     \
+  *aInstancePtr = foundInterface;                                       \
+  return status;                                                        \
+  }
+
+#define NS_IMPL_QUERY_TAIL_USING_AGGREGATOR(_aggregator)                 \
+  foundInterface = 0;                                                    \
+  nsresult status;                                                       \
+  if (!foundInterface) {                                                 \
+    NS_ASSERTION(_aggregator, "null aggregator");                        \
+    status = _aggregator->QueryInterface(aIID, (void**)&foundInterface); \
+  } else {                                                               \
+    NS_ADDREF(foundInterface);                                           \
+    status = NS_OK;                                                      \
+  }                                                                      \
+  *aInstancePtr = foundInterface;                                        \
+  return status;                                                         \
+  }
+
+#define NS_IMPL_QUERY_TAIL(_supports_interface)                  \
+  NS_IMPL_QUERY_BODY_AMBIGUOUS(nsISupports, _supports_interface) \
+  NS_IMPL_QUERY_TAIL_GUTS
+
+/*
+  This is the new scheme.  Using this notation now will allow us to switch to
+  a table driven mechanism when it's ready.  Note the difference between this
+  and the (currently) underlying NS_IMPL_QUERY_INTERFACE mechanism.  You must
+  explicitly mention |nsISupports| when using the interface maps.
+*/
+#define NS_INTERFACE_MAP_BEGIN(_implClass) NS_IMPL_QUERY_HEAD(_implClass)
+#define NS_INTERFACE_MAP_ENTRY(_interface) NS_IMPL_QUERY_BODY(_interface)
+#define NS_INTERFACE_MAP_ENTRY_CONDITIONAL(_interface, condition) \
+  NS_IMPL_QUERY_BODY_CONDITIONAL(_interface, condition)
+#define NS_INTERFACE_MAP_ENTRY_AGGREGATED(_interface, _aggregate) \
+  NS_IMPL_QUERY_BODY_AGGREGATED(_interface, _aggregate)
+
+#define NS_INTERFACE_MAP_END NS_IMPL_QUERY_TAIL_GUTS
+#define NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(_interface, _implClass) \
+  NS_IMPL_QUERY_BODY_AMBIGUOUS(_interface, _implClass)
+#define NS_INTERFACE_MAP_ENTRY_CONCRETE(_class) \
+  NS_IMPL_QUERY_BODY_CONCRETE(_class)
+#define NS_INTERFACE_MAP_END_INHERITING(_baseClass) \
+  NS_IMPL_QUERY_TAIL_INHERITING(_baseClass)
+#define NS_INTERFACE_MAP_END_AGGREGATED(_aggregator) \
+  NS_IMPL_QUERY_TAIL_USING_AGGREGATOR(_aggregator)
+
+#define NS_INTERFACE_TABLE0(_class)               \
+  NS_INTERFACE_TABLE_BEGIN                        \
+    NS_INTERFACE_TABLE_ENTRY(_class, nsISupports) \
+  NS_INTERFACE_TABLE_END
+
+#define NS_INTERFACE_TABLE(aClass, ...)                               \
+  static_assert(MOZ_ARG_COUNT(__VA_ARGS__) > 0,                       \
+                "Need more arguments to NS_INTERFACE_TABLE");         \
+  NS_INTERFACE_TABLE_BEGIN                                            \
+    MOZ_FOR_EACH(NS_INTERFACE_TABLE_ENTRY, (aClass, ), (__VA_ARGS__)) \
+    NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(aClass, nsISupports,           \
+                                       MOZ_ARG_1(__VA_ARGS__))        \
+  NS_INTERFACE_TABLE_END
+
+#define NS_IMPL_QUERY_INTERFACE0(_class) \
+  NS_INTERFACE_TABLE_HEAD(_class)        \
+    NS_INTERFACE_TABLE0(_class)          \
+  NS_INTERFACE_TABLE_TAIL
+
+#define NS_IMPL_QUERY_INTERFACE(aClass, ...) \
+  NS_INTERFACE_TABLE_HEAD(aClass)            \
+    NS_INTERFACE_TABLE(aClass, __VA_ARGS__)  \
+  NS_INTERFACE_TABLE_TAIL
+
+/**
+ * Declare that you're going to inherit from something that already
+ * implements nsISupports, but also implements an additional interface, thus
+ * causing an ambiguity. In this case you don't need another mRefCnt, you
+ * just need to forward the definitions to the appropriate superclass. E.g.
+ *
+ * class Bar : public Foo, public nsIBar {  // both provide nsISupports
+ * public:
+ *   NS_DECL_ISUPPORTS_INHERITED
+ *   ...other nsIBar and Bar methods...
+ * };
+ */
+#define NS_DECL_ISUPPORTS_INHERITED                                       \
+ public:                                                                  \
+  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override; \
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) override;             \
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) override;
+
+/**
+ * These macros can be used in conjunction with NS_DECL_ISUPPORTS_INHERITED
+ * to implement the nsISupports methods, forwarding the invocations to a
+ * superclass that already implements nsISupports. Don't do anything for
+ * subclasses of Runnable because it deals with subclass logging in its own
+ * way, using the mName field.
+ *
+ * Note that I didn't make these inlined because they're virtual methods.
+ */
+
+namespace mozilla {
+class Runnable;
+namespace detail {
+class SupportsThreadSafeWeakPtrBase;
+
+// Don't NS_LOG_{ADDREF,RELEASE} when inheriting from `Runnable*` or types with
+// thread safe weak references, as it will generate incorrect refcnt logs due to
+// the thread-safe `Upgrade()` call's refcount modifications not calling through
+// the derived class' `AddRef()` and `Release()` methods.
+template <typename T>
+constexpr bool ShouldLogInheritedRefcnt =
+    !std::is_convertible_v<T*, Runnable*> &&
+    !std::is_base_of_v<SupportsThreadSafeWeakPtrBase, T>;
+}
+}  // namespace mozilla
+
+#define NS_IMPL_ADDREF_INHERITED_GUTS(Class, Super)                   \
+  MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(Class)                           \
+  nsrefcnt r = Super::AddRef();                                       \
+  if constexpr (::mozilla::detail::ShouldLogInheritedRefcnt<Class>) { \
+    NS_LOG_ADDREF(this, r, #Class, sizeof(*this));                    \
+  }                                                                   \
+  return r /* Purposefully no trailing semicolon */
+
+#define NS_IMPL_ADDREF_INHERITED(Class, Super)                  \
+  NS_IMETHODIMP_(MozExternalRefCountType) Class::AddRef(void) { \
+    NS_IMPL_ADDREF_INHERITED_GUTS(Class, Super);                \
+  }
+
+#define NS_IMPL_RELEASE_INHERITED_GUTS(Class, Super)                  \
+  nsrefcnt r = Super::Release();                                      \
+  if constexpr (::mozilla::detail::ShouldLogInheritedRefcnt<Class>) { \
+    NS_LOG_RELEASE(this, r, #Class);                                  \
+  }                                                                   \
+  return r /* Purposefully no trailing semicolon */
+
+#define NS_IMPL_RELEASE_INHERITED(Class, Super)                  \
+  NS_IMETHODIMP_(MozExternalRefCountType) Class::Release(void) { \
+    NS_IMPL_RELEASE_INHERITED_GUTS(Class, Super);                \
+  }
+
+/**
+ * As above but not logging the addref/release; needed if the base
+ * class might be aggregated.
+ */
+#define NS_IMPL_NONLOGGING_ADDREF_INHERITED(Class, Super)       \
+  NS_IMETHODIMP_(MozExternalRefCountType) Class::AddRef(void) { \
+    MOZ_ASSERT_TYPE_OK_FOR_REFCOUNTING(Class)                   \
+    return Super::AddRef();                                     \
+  }
+
+#define NS_IMPL_NONLOGGING_RELEASE_INHERITED(Class, Super)       \
+  NS_IMETHODIMP_(MozExternalRefCountType) Class::Release(void) { \
+    return Super::Release();                                     \
+  }
+
+#define NS_INTERFACE_TABLE_INHERITED0(Class) /* Nothing to do here */
+
+#define NS_INTERFACE_TABLE_INHERITED(aClass, ...)                       \
+  static_assert(MOZ_ARG_COUNT(__VA_ARGS__) > 0,                         \
+                "Need more arguments to NS_INTERFACE_TABLE_INHERITED"); \
+  NS_INTERFACE_TABLE_BEGIN                                              \
+    MOZ_FOR_EACH(NS_INTERFACE_TABLE_ENTRY, (aClass, ), (__VA_ARGS__))   \
+  NS_INTERFACE_TABLE_END
+
+#define NS_IMPL_QUERY_INTERFACE_INHERITED(aClass, aSuper, ...) \
+  NS_INTERFACE_TABLE_HEAD(aClass)                              \
+    NS_INTERFACE_TABLE_INHERITED(aClass, __VA_ARGS__)          \
+  NS_INTERFACE_TABLE_TAIL_INHERITING(aSuper)
+
+/**
+ * Convenience macros for implementing all nsISupports methods for
+ * a simple class.
+ * @param _class The name of the class implementing the method
+ * @param _classiiddef The name of the #define symbol that defines the IID
+ * for the class (e.g. NS_ISUPPORTS_IID)
+ */
+
+#define NS_IMPL_ISUPPORTS0(_class) \
+  NS_IMPL_ADDREF(_class)           \
+  NS_IMPL_RELEASE(_class)          \
+  NS_IMPL_QUERY_INTERFACE0(_class)
+
+#define NS_IMPL_ISUPPORTS(aClass, ...) \
+  NS_IMPL_ADDREF(aClass)               \
+  NS_IMPL_RELEASE(aClass)              \
+  NS_IMPL_QUERY_INTERFACE(aClass, __VA_ARGS__)
+
+// When possible, prefer NS_INLINE_DECL_REFCOUNTING_INHERITED to
+// NS_IMPL_ISUPPORTS_INHERITED0.
+#define NS_IMPL_ISUPPORTS_INHERITED0(aClass, aSuper) \
+  NS_INTERFACE_TABLE_HEAD(aClass)                    \
+  NS_INTERFACE_TABLE_TAIL_INHERITING(aSuper)         \
+  NS_IMPL_ADDREF_INHERITED(aClass, aSuper)           \
+  NS_IMPL_RELEASE_INHERITED(aClass, aSuper)
+
+#define NS_IMPL_ISUPPORTS_INHERITED(aClass, aSuper, ...)         \
+  NS_IMPL_QUERY_INTERFACE_INHERITED(aClass, aSuper, __VA_ARGS__) \
+  NS_IMPL_ADDREF_INHERITED(aClass, aSuper)                       \
+  NS_IMPL_RELEASE_INHERITED(aClass, aSuper)
+
+/**
+ * A macro to declare and implement inherited addref/release for a class which
+ * doesn't have or need to override QueryInterface from its base class.
+ *
+ * Note: This macro always overrides the `AddRef` and `Release` methods,
+ * including when refcount logging is disabled, meaning that it will implement
+ * the `AddRef` or `Release` method from another virtual base class.
+ */
+#define NS_INLINE_DECL_REFCOUNTING_INHERITED(Class, Super)  \
+  NS_IMETHOD_(MozExternalRefCountType) AddRef() override {  \
+    NS_IMPL_ADDREF_INHERITED_GUTS(Class, Super);            \
+  }                                                         \
+  NS_IMETHOD_(MozExternalRefCountType) Release() override { \
+    NS_IMPL_RELEASE_INHERITED_GUTS(Class, Super);           \
+  }
+
+/*
+ * Macro to glue together a QI that starts with an interface table
+ * and segues into an interface map (e.g. it uses singleton classinfo
+ * or tearoffs).
+ */
+#define NS_INTERFACE_TABLE_TO_MAP_SEGUE \
+  if (rv == NS_OK) return rv;           \
+  nsISupports* foundInterface;
+
+///////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Macro to generate nsIClassInfo methods for classes which do not have
+ * corresponding nsIFactory implementations.
+ */
+#define NS_IMPL_THREADSAFE_CI(_class)                          \
+  NS_IMETHODIMP                                                \
+  _class::GetInterfaces(nsTArray<nsIID>& _array) {             \
+    return NS_CI_INTERFACE_GETTER_NAME(_class)(_array);        \
+  }                                                            \
+                                                               \
+  NS_IMETHODIMP                                                \
+  _class::GetScriptableHelper(nsIXPCScriptable** _retval) {    \
+    *_retval = nullptr;                                        \
+    return NS_OK;                                              \
+  }                                                            \
+                                                               \
+  NS_IMETHODIMP                                                \
+  _class::GetContractID(nsACString& _contractID) {             \
+    _contractID.SetIsVoid(true);                               \
+    return NS_OK;                                              \
+  }                                                            \
+                                                               \
+  NS_IMETHODIMP                                                \
+  _class::GetClassDescription(nsACString& _classDescription) { \
+    _classDescription.SetIsVoid(true);                         \
+    return NS_OK;                                              \
+  }                                                            \
+                                                               \
+  NS_IMETHODIMP                                                \
+  _class::GetClassID(nsCID** _classID) {                       \
+    *_classID = nullptr;                                       \
+    return NS_OK;                                              \
+  }                                                            \
+                                                               \
+  NS_IMETHODIMP                                                \
+  _class::GetFlags(uint32_t* _flags) {                         \
+    *_flags = nsIClassInfo::THREADSAFE;                        \
+    return NS_OK;                                              \
+  }                                                            \
+                                                               \
+  NS_IMETHODIMP                                                \
+  _class::GetClassIDNoAlloc(nsCID* _classIDNoAlloc) {          \
+    return NS_ERROR_NOT_AVAILABLE;                             \
+  }
+
+#endif