Find out which theme function to call to alter each element on page

This is a hack on how to get output of which theme function to call to alter each element on page. So you will need to go to In includes/theme.inc in the Drupal 7 theme() function, around line 1161 and change $output from one line to two lines and to have this code below. You will get theme suggestions all around the page, which will be messy but will help you find what you need.

  // Generate the output using either a function or a template.
  $output = '';
  if (isset($info['function'])) {
    if (function_exists($info['function'])) {
      $output = '<div>' . $info['function'] . '</div';
      $output .= $info['function']($variables);
    }
  }