def ProcessLine(filename, linenumber, clean_lines, errors):
    """
    Arguments:
      filename    the name of the file
      linenumber  the line number index
      clean_lines CleansedLines instance
      errors      the error handling function
    """
    CheckLintPragma(filename, linenumber, clean_lines.raw_lines[linenumber], errors)
    CheckLineLength(filename, linenumber, clean_lines, errors)
    CheckUpperLowerCase(filename, linenumber, clean_lines, errors)
    CheckStyle(filename, linenumber, clean_lines, errors)
    if IsFindPackage(filename):
        CheckFindPackage(filename, linenumber, clean_lines, errors)