diff -r 000000000000 -r 6474c204b198 js/src/jsalloc.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jsalloc.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,88 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+/*
+ * JS allocation policies.
+ *
+ * The allocators here are for system memory with lifetimes which are not
+ * managed by the GC. See the comment at the top of vm/MallocProvider.h.
+ */
+
+#ifndef jsalloc_h
+#define jsalloc_h
+
+#include "js/TypeDecls.h"
+#include "js/Utility.h"
+
+namespace js {
+
+class ContextFriendFields;
+
+/* Policy for using system memory functions and doing no error reporting. */
+class SystemAllocPolicy
+{
+  public:
+    void *malloc_(size_t bytes) { return js_malloc(bytes); }
+    void *calloc_(size_t bytes) { return js_calloc(bytes); }
+    void *realloc_(void *p, size_t oldBytes, size_t bytes) { return js_realloc(p, bytes); }
+    void free_(void *p) { js_free(p); }
+    void reportAllocOverflow() const {}
+};
+
+/*
+ * Allocation policy that calls the system memory functions and reports errors
+ * to the context. Since the JSContext given on construction is stored for
+ * the lifetime of the container, this policy may only be used for containers
+ * whose lifetime is a shorter than the given JSContext.
+ *
+ * FIXME bug 647103 - rewrite this in terms of temporary allocation functions,
+ * not the system ones.
+ */
+class TempAllocPolicy
+{
+    ContextFriendFields *const cx_;
+
+    /*
+     * Non-inline helper to call JSRuntime::onOutOfMemory with minimal
+     * code bloat.
+     */
+    JS_FRIEND_API(void *) onOutOfMemory(void *p, size_t nbytes);
+
+  public:
+    TempAllocPolicy(JSContext *cx) : cx_((ContextFriendFields *) cx) {} // :(
+    TempAllocPolicy(ContextFriendFields *cx) : cx_(cx) {}
+
+    void *malloc_(size_t bytes) {
+        void *p = js_malloc(bytes);
+        if (MOZ_UNLIKELY(!p))
+            p = onOutOfMemory(nullptr, bytes);
+        return p;
+    }
+
+    void *calloc_(size_t bytes) {
+        void *p = js_calloc(bytes);
+        if (MOZ_UNLIKELY(!p))
+            p = onOutOfMemory(nullptr, bytes);
+        return p;
+    }
+
+    void *realloc_(void *p, size_t oldBytes, size_t bytes) {
+        void *p2 = js_realloc(p, bytes);
+        if (MOZ_UNLIKELY(!p2))
+            p2 = onOutOfMemory(p2, bytes);
+        return p2;
+    }
+
+    void free_(void *p) {
+        js_free(p);
+    }
+
+    JS_FRIEND_API(void) reportAllocOverflow() const;
+};
+
+} /* namespace js */
+
+#endif /* jsalloc_h */