inc/ErrorHandler.php

   1 <?php
   2
   3 namespace dokuwiki;
   4
   5 use dokuwiki\Exception\FatalException;
   6
   7 /**
   8  * Manage the global handling of errors and exceptions
   9  *
  10  * Developer may use this to log and display exceptions themselves
  11  */
  12 class ErrorHandler
  13 {
  14     /**
  15      * Standard error codes used in PHP errors
  16      * @see https://www.php.net/manual/en/errorfunc.constants.php
  17      */
  18     protected const ERRORCODES = [
  19         1 => 'E_ERROR',
  20         2 => 'E_WARNING',
  21         4 => 'E_PARSE',
  22         8 => 'E_NOTICE',
  23         16 => 'E_CORE_ERROR',
  24         32 => 'E_CORE_WARNING',
  25         64 => 'E_COMPILE_ERROR',
  26         128 => 'E_COMPILE_WARNING',
  27         256 => 'E_USER_ERROR',
  28         512 => 'E_USER_WARNING',
  29         1024 => 'E_USER_NOTICE',
  30         2048 => 'E_STRICT',
  31         4096 => 'E_RECOVERABLE_ERROR',
  32         8192 => 'E_DEPRECATED',
  33         16384 => 'E_USER_DEPRECATED',
  34     ];
  35
  36     /**
  37      * Register the default error handling
  38      */
  39     public static function register()
  40     {
  41         if (!defined('DOKU_UNITTEST')) {
  42             set_exception_handler([ErrorHandler::class, 'fatalException']);
  43             register_shutdown_function([ErrorHandler::class, 'fatalShutdown']);
  44             set_error_handler(
  45                 [ErrorHandler::class, 'errorHandler'],
  46                 E_WARNING | E_USER_ERROR | E_USER_WARNING | E_RECOVERABLE_ERROR
  47             );
  48         }
  49     }
  50
  51     /**
  52      * Default Exception handler to show a nice user message before dieing
  53      *
  54      * The exception is logged to the error log
  55      *
  56      * @param \Throwable $e
  57      */
  58     public static function fatalException($e)
  59     {
  60         $plugin = self::guessPlugin($e);
  61         $title = hsc(get_class($e) . ': ' . $e->getMessage());
  62         $msg = 'An unforeseen error has occured. This is most likely a bug somewhere.';
  63         if ($plugin) $msg .= ' It might be a problem in the ' . $plugin . ' plugin.';
  64         $logged = self::logException($e)
  65             ? 'More info has been written to the DokuWiki error log.'
  66             : $e->getFile() . ':' . $e->getLine();
  67
  68         echo <<<EOT
  69 <!DOCTYPE html>
  70 <html>
  71 <head><title>$title</title></head>
  72 <body style="font-family: Arial, sans-serif">
  73     <div style="width:60%; margin: auto; background-color: #fcc;
  74                 border: 1px solid #faa; padding: 0.5em 1em;">
  75         <h1 style="font-size: 120%">$title</h1>
  76         <p>$msg</p>
  77         <p>$logged</p>
  78     </div>
  79 </body>
  80 </html>
  81 EOT;
  82     }
  83
  84     /**
  85      * Convenience method to display an error message for the given Exception
  86      *
  87      * @param \Throwable $e
  88      * @param string $intro
  89      */
  90     public static function showExceptionMsg($e, $intro = 'Error!')
  91     {
  92         $msg = hsc($intro) . '<br />' . hsc(get_class($e) . ': ' . $e->getMessage());
  93         if (self::logException($e)) $msg .= '<br />More info is available in the error log.';
  94         msg($msg, -1);
  95     }
  96
  97     /**
  98      * Last resort to handle fatal errors that still can't be caught
  99      */
 100     public static function fatalShutdown()
 101     {
 102         $error = error_get_last();
 103         // Check if it's a core/fatal error, otherwise it's a normal shutdown
 104         if (
 105             $error !== null &&
 106             in_array(
 107                 $error['type'],
 108                 [
 109                     E_ERROR,
 110                     E_CORE_ERROR,
 111                     E_COMPILE_ERROR,
 112                 ]
 113             )
 114         ) {
 115             self::fatalException(
 116                 new FatalException($error['message'], 0, $error['type'], $error['file'], $error['line'])
 117             );
 118         }
 119     }
 120
 121     /**
 122      * Log the given exception to the error log
 123      *
 124      * @param \Throwable $e
 125      * @return bool false if the logging failed
 126      */
 127     public static function logException($e)
 128     {
 129         if ($e instanceof \ErrorException) {
 130             $prefix = self::ERRORCODES[$e->getSeverity()];
 131         } else {
 132             $prefix = get_class($e);
 133         }
 134
 135         return Logger::getInstance()->log(
 136             $prefix . ': ' . $e->getMessage(),
 137             $e->getTraceAsString(),
 138             $e->getFile(),
 139             $e->getLine()
 140         );
 141     }
 142
 143     /**
 144      * Error handler to log non-exception errors
 145      *
 146      * @param int $errno
 147      * @param string $errstr
 148      * @param string $errfile
 149      * @param int $errline
 150      * @return bool
 151      */
 152     public static function errorHandler($errno, $errstr, $errfile, $errline)
 153     {
 154         global $conf;
 155
 156         // ignore supressed warnings
 157         if (!(error_reporting() & $errno)) return false;
 158
 159         $ex = new \ErrorException(
 160             $errstr,
 161             0,
 162             $errno,
 163             $errfile,
 164             $errline
 165         );
 166         self::logException($ex);
 167
 168         if ($ex->getSeverity() === E_WARNING && $conf['hidewarnings']) {
 169             return true;
 170         }
 171
 172         return false;
 173     }
 174
 175     /**
 176      * Checks the the stacktrace for plugin files
 177      *
 178      * @param \Throwable $e
 179      * @return false|string
 180      */
 181     protected static function guessPlugin($e)
 182     {
 183         if (preg_match('/lib\/plugins\/(\w+)\//', str_replace('\\', '/', $e->getFile()), $match)) {
 184             return $match[1];
 185         }
 186
 187         foreach ($e->getTrace() as $line) {
 188             if (
 189                 isset($line['class']) &&
 190                 preg_match('/\w+?_plugin_(\w+)/', $line['class'], $match)
 191             ) {
 192                 return $match[1];
 193             }
 194
 195             if (
 196                 isset($line['file']) &&
 197                 preg_match('/lib\/plugins\/(\w+)\//', str_replace('\\', '/', $line['file']), $match)
 198             ) {
 199                 return $match[1];
 200             }
 201         }
 202
 203         return false;
 204     }
 205 }