diff -r 000000000000 -r 6474c204b198 js/src/jsversion.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jsversion.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,44 @@
+/* -*- 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/. */
+
+#ifndef jsversion_h
+#define jsversion_h
+
+/*
+ * JS Capability Macros.
+ */
+#define JS_HAS_STR_HTML_HELPERS 1       /* has str.anchor, str.bold, etc. */
+#define JS_HAS_OBJ_PROTO_PROP   1       /* has o.__proto__ etc. */
+#define JS_HAS_OBJ_WATCHPOINT   1       /* has o.watch and o.unwatch */
+#define JS_HAS_TOSOURCE         1       /* has Object/Array toSource method */
+#define JS_HAS_CATCH_GUARD      1       /* has exception handling catch guard */
+#define JS_HAS_UNEVAL           1       /* has uneval() top-level function */
+#define JS_HAS_CONST            1       /* has JS2 const as alternative var */
+#define JS_HAS_FUN_EXPR_STMT    1       /* has function expression statement */
+#define JS_HAS_NO_SUCH_METHOD   1       /* has o.__noSuchMethod__ handler */
+#define JS_HAS_FOR_EACH_IN      1       /* has for each (lhs in iterable) */
+#define JS_HAS_GENERATORS       1       /* has yield in generator function */
+#define JS_HAS_BLOCK_SCOPE      1       /* has block scope via let/arraycomp */
+#define JS_HAS_DESTRUCTURING    2       /* has [a,b] = ... or {p:a,q:b} = ... */
+#define JS_HAS_GENERATOR_EXPRS  1       /* has (expr for (lhs in iterable)) */
+#define JS_HAS_EXPR_CLOSURES    1       /* has function (formals) listexpr */
+
+/* Support for JS_NewGlobalObject. */
+#define JS_HAS_NEW_GLOBAL_OBJECT        1
+
+/* Support for JS_MakeSystemObject. */
+#define JS_HAS_MAKE_SYSTEM_OBJECT       1
+
+/* Feature-test macro for evolving destructuring support. */
+#define JS_HAS_DESTRUCTURING_SHORTHAND  (JS_HAS_DESTRUCTURING == 2)
+
+/*
+ * Feature for Object.prototype.__{define,lookup}{G,S}etter__ legacy support;
+ * support likely to be made opt-in at some future time.
+ */
+#define JS_OLD_GETTER_SETTER_METHODS    1
+
+#endif /* jsversion_h */