code: def ProcessFileData(filename, file_extension, lines, error,
                      extra_check_functions=None):
    
    lines = (['// marker so line numbers and indices both start at 1'] + lines +
             ['// marker so line numbers end in a known way'])
  
    include_state = _IncludeState()
    function_state = _FunctionState()
    nesting_state = NestingState()
  
    ResetNolintSuppressions()
  
    CheckForCopyright(filename, lines, error)
    ProcessGlobalSuppresions(lines)
    RemoveMultiLineComments(filename, lines, error)
    clean_lines = CleansedLines(lines)
  
    if file_extension in GetHeaderExtensions():
      CheckForHeaderGuard(filename, clean_lines, error)
  
    for line in range(clean_lines.NumLines()):
      ProcessLine(filename, file_extension, clean_lines, line,
                  include_state, function_state, nesting_state, error,
                  extra_check_functions)
      FlagCxx11Features(filename, clean_lines, line, error)
    nesting_state.CheckCompletedBlocks(filename, error)
  
    CheckForIncludeWhatYouUse(filename, clean_lines, include_state, error)
  
    # Check that the .cc file has included its header if it exists.
    if _IsSourceExtension(file_extension):
      CheckHeaderFileIncluded(filename, include_state, error)
  
    # We check here rather than inside ProcessLine so that we see raw
    # lines rather than "cleaned" lines.
    CheckForBadCharacters(filename, lines, error)
  
    CheckForNewlineAtEOF(filename, lines, error)
docs: Performs lint checks and reports any errors to the given error function.
  
    Args:
      filename: Filename of the file that is being processed.
      file_extension: The extension (dot not included) of the file.
      lines: An array of strings, each representing a line of the file, with the
             last element being empty if the file is terminated with a newline.
      error: A callable to which errors are reported, which takes 4 arguments:
             filename, line number, error level, and message
      extra_check_functions: An array of additional check functions that will be
                             run on each source line. Each function takes 4
                             arguments: filename, clean_lines, line, error