in scripts/extract_source.rb [156:168]
def initialize(filename, basepath, references = {}, static_symbols = [],
symbol_to_file = {}, file_to_symbol_positions = {}, external_variables = [],
included_files = [])
@filename = filename
@basepath = basepath
@references = references
@static_symbols = static_symbols
@symbol_to_file = symbol_to_file
@file_to_symbol_positions = file_to_symbol_positions
@external_variables = external_variables
@included_files = included_files
end