1 files changed, 29 insertions, 0 deletions
diff --git a/js/src/builtin/Boolean-inl.h b/js/src/builtin/Boolean-inl.h
new file mode 100644
index 0000000000..e4c02e1bd2
--- /dev/null
+++ b/js/src/builtin/Boolean-inl.h
@@ -0,0 +1,29 @@
+/* -*- 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/. */
+
+#ifndef builtin_Boolean_inl_h
+#define builtin_Boolean_inl_h
+
+#include "builtin/Boolean.h"
+
+#include "vm/JSContext.h"
+#include "vm/WrapperObject.h"
+
+namespace js {
+
+inline bool EmulatesUndefined(JSObject* obj) {
+  // This may be called off the main thread. It's OK not to expose the object
+  // here as it doesn't escape.
+  AutoUnsafeCallWithABI unsafe(UnsafeABIStrictness::AllowPendingExceptions);
+  JSObject* actual = MOZ_LIKELY(!obj->is<WrapperObject>())
+                         ? obj
+                         : UncheckedUnwrapWithoutExpose(obj);
+  return actual->getClass()->emulatesUndefined();
+}
+
+} /* namespace js */
+
+#endif /* builtin_Boolean_inl_h */