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diff --git a/js/public/AllocationLogging.h b/js/public/AllocationLogging.h
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+/* -*- 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/. */
+
+/*
+ * Embedder-supplied tracking of the allocation and deallocation of various
+ * non-garbage-collected objects in SpiderMonkey.
+ *
+ * This functionality is intended to track allocation of non-user-visible
+ * structures, for debugging the C++ of an embedding.  It is not intended to
+ * give the end user visibility into allocations in JS.  Instead see
+ * AllocationRecording.h for such functionality.
+ */
+
+#ifndef js_AllocationLogging_h
+#define js_AllocationLogging_h
+
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/PodOperations.h"
+
+#include <stdint.h>  // uint32_t
+
+#include "jstypes.h"  // JS_PUBLIC_API
+
+namespace JS {
+
+using LogCtorDtor = void (*)(void*, const char*, uint32_t);
+
+/**
+ * Set global functions used to monitor classes to highlight leaks.
+ *
+ * For each C++ class that uses these mechanisms, the allocation of an instance
+ * will log the constructor call, and its subsequent deallocation will log the
+ * destructor call.  If only the former occurs, the instance/allocation is
+ * leaked.  With carefully-written logging functions, this can be used to debug
+ * the origin of the leaks.
+ */
+extern JS_PUBLIC_API void SetLogCtorDtorFunctions(LogCtorDtor ctor,
+                                                  LogCtorDtor dtor);
+
+/**
+ * Log the allocation of |self|, having a type uniquely identified by the string
+ * |type|, with allocation size |sz|.
+ *
+ * You generally should use |JS_COUNT_CTOR| and |JS_COUNT_DTOR| instead of
+ * using this function directly.
+ */
+extern JS_PUBLIC_API void LogCtor(void* self, const char* type, uint32_t sz);
+
+/**
+ * Log the deallocation of |self|, having a type uniquely identified by the
+ * string |type|, with allocation size |sz|.
+ *
+ * You generally should use |JS_COUNT_CTOR| and |JS_COUNT_DTOR| instead of
+ * using this function directly.
+ */
+extern JS_PUBLIC_API void LogDtor(void* self, const char* type, uint32_t sz);
+
+/**
+ * Within each non-delegating constructor of a |Class|, use
+ * |JS_COUNT_CTOR(Class);| to log the allocation of |this|.  (If you do this in
+ * delegating constructors, you might count a single allocation multiple times.)
+ */
+#define JS_COUNT_CTOR(Class) \
+  (::JS::LogCtor(static_cast<void*>(this), #Class, sizeof(Class)))
+
+/**
+ * Within the destructor of a |Class|, use |JS_COUNT_DTOR(Class);| to log the
+ * deallocation of |this|.
+ */
+#define JS_COUNT_DTOR(Class) \
+  (::JS::LogDtor(static_cast<void*>(this), #Class, sizeof(Class)))
+
+}  // namespace JS
+
+#endif  // js_AllocationLogging_h