def add_targets_to_INSTALLED_FILES(target, source, env):
    """ An emitter that adds all target files to the list stored in the
    _INSTALLED_FILES global variable. This way all installed files of one
    scons call will be collected.
    """
    global _INSTALLED_FILES, _UNIQUE_INSTALLED_FILES
    _INSTALLED_FILES.extend(target)

    _UNIQUE_INSTALLED_FILES = None
    return (target, source)