Question

How can I find any unused functions in a PHP project?

Are there features or APIs built into PHP that will allow me to analyse my codebase – for example Reflection, token_get_all()?

Are these APIs feature rich enough for me not to have to rely on a third party tool to perform this type of analysis?

Answer 1

Thanks Greg and Dave for the feedback. Wasn’t quite what I was looking for, but I decided to put a bit of time into researching it and came up with this quick and dirty solution:

<?php     $functions = array();     $path = '/path/to/my/php/project';     define_dir($path, $functions);     reference_dir($path, $functions);     echo         '<table>' .             '<tr>' .                 '<th>Name</th>' .                 '<th>Defined</th>' .                 '<th>Referenced</th>' .             '</tr>';     foreach ($functions as $name => $value) {         echo             '<tr>' .                  '<td>' . htmlentities($name) . '</td>' .                 '<td>' . (isset($value[0]) ? count($value[0]) : '-') . '</td>' .                 '<td>' . (isset($value[1]) ? count($value[1]) : '-') . '</td>' .             '</tr>';     }     echo '</table>';     function define_dir($path, &$functions) {         if ($dir = opendir($path)) {             while (($file = readdir($dir)) !== false) {                 if (substr($file, 0, 1) == '.') continue;                 if (is_dir($path . '/' . $file)) {                     define_dir($path . '/' . $file, $functions);                 } else {                     if (substr($file, - 4, 4) != '.php') continue;                     define_file($path . '/' . $file, $functions);                 }             }         }            }     function define_file($path, &$functions) {         $tokens = token_get_all(file_get_contents($path));         for ($i = 0; $i < count($tokens); $i++) {             $token = $tokens[$i];             if (is_array($token)) {                 if ($token[0] != T_FUNCTION) continue;                 $i++;                 $token = $tokens[$i];                 if ($token[0] != T_WHITESPACE) die('T_WHITESPACE');                 $i++;                 $token = $tokens[$i];                 if ($token[0] != T_STRING) die('T_STRING');                 $functions[$token[1]][0][] = array($path, $token[2]);             }         }     }     function reference_dir($path, &$functions) {         if ($dir = opendir($path)) {             while (($file = readdir($dir)) !== false) {                 if (substr($file, 0, 1) == '.') continue;                 if (is_dir($path . '/' . $file)) {                     reference_dir($path . '/' . $file, $functions);                 } else {                     if (substr($file, - 4, 4) != '.php') continue;                     reference_file($path . '/' . $file, $functions);                 }             }         }            }     function reference_file($path, &$functions) {         $tokens = token_get_all(file_get_contents($path));         for ($i = 0; $i < count($tokens); $i++) {             $token = $tokens[$i];             if (is_array($token)) {                 if ($token[0] != T_STRING) continue;                 if ($tokens[$i + 1] != '(') continue;                 $functions[$token[1]][1][] = array($path, $token[2]);             }         }     } ?> 

I’ll probably spend some more time on it so I can quickly find the files and line numbers of the function definitions and references; this information is being gathered, just not displayed.