vendor/symfony/debug/ErrorHandler.php

   1 <?php
   2
   3 /*
   4  * This file is part of the Symfony package.
   5  *
   6  * (c) Fabien Potencier <fabien@symfony.com>
   7  *
   8  * For the full copyright and license information, please view the LICENSE
   9  * file that was distributed with this source code.
  10  */
  11
  12 namespace Symfony\Component\Debug;
  13
  14 use Psr\Log\LogLevel;
  15 use Psr\Log\LoggerInterface;
  16 use Symfony\Component\Debug\Exception\ContextErrorException;
  17 use Symfony\Component\Debug\Exception\FatalErrorException;
  18 use Symfony\Component\Debug\Exception\FatalThrowableError;
  19 use Symfony\Component\Debug\Exception\OutOfMemoryException;
  20 use Symfony\Component\Debug\Exception\SilencedErrorContext;
  21 use Symfony\Component\Debug\FatalErrorHandler\UndefinedFunctionFatalErrorHandler;
  22 use Symfony\Component\Debug\FatalErrorHandler\UndefinedMethodFatalErrorHandler;
  23 use Symfony\Component\Debug\FatalErrorHandler\ClassNotFoundFatalErrorHandler;
  24 use Symfony\Component\Debug\FatalErrorHandler\FatalErrorHandlerInterface;
  25
  26 /**
  27  * A generic ErrorHandler for the PHP engine.
  28  *
  29  * Provides five bit fields that control how errors are handled:
  30  * - thrownErrors: errors thrown as \ErrorException
  31  * - loggedErrors: logged errors, when not @-silenced
  32  * - scopedErrors: errors thrown or logged with their local context
  33  * - tracedErrors: errors logged with their stack trace
  34  * - screamedErrors: never @-silenced errors
  35  *
  36  * Each error level can be logged by a dedicated PSR-3 logger object.
  37  * Screaming only applies to logging.
  38  * Throwing takes precedence over logging.
  39  * Uncaught exceptions are logged as E_ERROR.
  40  * E_DEPRECATED and E_USER_DEPRECATED levels never throw.
  41  * E_RECOVERABLE_ERROR and E_USER_ERROR levels always throw.
  42  * Non catchable errors that can be detected at shutdown time are logged when the scream bit field allows so.
  43  * As errors have a performance cost, repeated errors are all logged, so that the developer
  44  * can see them and weight them as more important to fix than others of the same level.
  45  *
  46  * @author Nicolas Grekas <p@tchwork.com>
  47  * @author Grégoire Pineau <lyrixx@lyrixx.info>
  48  */
  49 class ErrorHandler
  50 {
  51     private $levels = array(
  52         E_DEPRECATED => 'Deprecated',
  53         E_USER_DEPRECATED => 'User Deprecated',
  54         E_NOTICE => 'Notice',
  55         E_USER_NOTICE => 'User Notice',
  56         E_STRICT => 'Runtime Notice',
  57         E_WARNING => 'Warning',
  58         E_USER_WARNING => 'User Warning',
  59         E_COMPILE_WARNING => 'Compile Warning',
  60         E_CORE_WARNING => 'Core Warning',
  61         E_USER_ERROR => 'User Error',
  62         E_RECOVERABLE_ERROR => 'Catchable Fatal Error',
  63         E_COMPILE_ERROR => 'Compile Error',
  64         E_PARSE => 'Parse Error',
  65         E_ERROR => 'Error',
  66         E_CORE_ERROR => 'Core Error',
  67     );
  68
  69     private $loggers = array(
  70         E_DEPRECATED => array(null, LogLevel::INFO),
  71         E_USER_DEPRECATED => array(null, LogLevel::INFO),
  72         E_NOTICE => array(null, LogLevel::WARNING),
  73         E_USER_NOTICE => array(null, LogLevel::WARNING),
  74         E_STRICT => array(null, LogLevel::WARNING),
  75         E_WARNING => array(null, LogLevel::WARNING),
  76         E_USER_WARNING => array(null, LogLevel::WARNING),
  77         E_COMPILE_WARNING => array(null, LogLevel::WARNING),
  78         E_CORE_WARNING => array(null, LogLevel::WARNING),
  79         E_USER_ERROR => array(null, LogLevel::CRITICAL),
  80         E_RECOVERABLE_ERROR => array(null, LogLevel::CRITICAL),
  81         E_COMPILE_ERROR => array(null, LogLevel::CRITICAL),
  82         E_PARSE => array(null, LogLevel::CRITICAL),
  83         E_ERROR => array(null, LogLevel::CRITICAL),
  84         E_CORE_ERROR => array(null, LogLevel::CRITICAL),
  85     );
  86
  87     private $thrownErrors = 0x1FFF; // E_ALL - E_DEPRECATED - E_USER_DEPRECATED
  88     private $scopedErrors = 0x1FFF; // E_ALL - E_DEPRECATED - E_USER_DEPRECATED
  89     private $tracedErrors = 0x77FB; // E_ALL - E_STRICT - E_PARSE
  90     private $screamedErrors = 0x55; // E_ERROR + E_CORE_ERROR + E_COMPILE_ERROR + E_PARSE
  91     private $loggedErrors = 0;
  92     private $traceReflector;
  93
  94     private $isRecursive = 0;
  95     private $isRoot = false;
  96     private $exceptionHandler;
  97     private $bootstrappingLogger;
  98
  99     private static $reservedMemory;
 100     private static $stackedErrors = array();
 101     private static $stackedErrorLevels = array();
 102     private static $toStringException = null;
 103     private static $silencedErrorCache = array();
 104     private static $silencedErrorCount = 0;
 105     private static $exitCode = 0;
 106
 107     /**
 108      * Registers the error handler.
 109      *
 110      * @param self|null $handler The handler to register
 111      * @param bool      $replace Whether to replace or not any existing handler
 112      *
 113      * @return self The registered error handler
 114      */
 115     public static function register(self $handler = null, $replace = true)
 116     {
 117         if (null === self::$reservedMemory) {
 118             self::$reservedMemory = str_repeat('x', 10240);
 119             register_shutdown_function(__CLASS__.'::handleFatalError');
 120         }
 121
 122         if ($handlerIsNew = null === $handler) {
 123             $handler = new static();
 124         }
 125
 126         if (null === $prev = set_error_handler(array($handler, 'handleError'))) {
 127             restore_error_handler();
 128             // Specifying the error types earlier would expose us to https://bugs.php.net/63206
 129             set_error_handler(array($handler, 'handleError'), $handler->thrownErrors | $handler->loggedErrors);
 130             $handler->isRoot = true;
 131         }
 132
 133         if ($handlerIsNew && is_array($prev) && $prev[0] instanceof self) {
 134             $handler = $prev[0];
 135             $replace = false;
 136         }
 137         if (!$replace && $prev) {
 138             restore_error_handler();
 139             $handlerIsRegistered = is_array($prev) && $handler === $prev[0];
 140         } else {
 141             $handlerIsRegistered = true;
 142         }
 143         if (is_array($prev = set_exception_handler(array($handler, 'handleException'))) && $prev[0] instanceof self) {
 144             restore_exception_handler();
 145             if (!$handlerIsRegistered) {
 146                 $handler = $prev[0];
 147             } elseif ($handler !== $prev[0] && $replace) {
 148                 set_exception_handler(array($handler, 'handleException'));
 149                 $p = $prev[0]->setExceptionHandler(null);
 150                 $handler->setExceptionHandler($p);
 151                 $prev[0]->setExceptionHandler($p);
 152             }
 153         } else {
 154             $handler->setExceptionHandler($prev);
 155         }
 156
 157         $handler->throwAt(E_ALL & $handler->thrownErrors, true);
 158
 159         return $handler;
 160     }
 161
 162     public function __construct(BufferingLogger $bootstrappingLogger = null)
 163     {
 164         if ($bootstrappingLogger) {
 165             $this->bootstrappingLogger = $bootstrappingLogger;
 166             $this->setDefaultLogger($bootstrappingLogger);
 167         }
 168         $this->traceReflector = new \ReflectionProperty('Exception', 'trace');
 169         $this->traceReflector->setAccessible(true);
 170     }
 171
 172     /**
 173      * Sets a logger to non assigned errors levels.
 174      *
 175      * @param LoggerInterface $logger  A PSR-3 logger to put as default for the given levels
 176      * @param array|int       $levels  An array map of E_* to LogLevel::* or an integer bit field of E_* constants
 177      * @param bool            $replace Whether to replace or not any existing logger
 178      */
 179     public function setDefaultLogger(LoggerInterface $logger, $levels = E_ALL, $replace = false)
 180     {
 181         $loggers = array();
 182
 183         if (is_array($levels)) {
 184             foreach ($levels as $type => $logLevel) {
 185                 if (empty($this->loggers[$type][0]) || $replace || $this->loggers[$type][0] === $this->bootstrappingLogger) {
 186                     $loggers[$type] = array($logger, $logLevel);
 187                 }
 188             }
 189         } else {
 190             if (null === $levels) {
 191                 $levels = E_ALL;
 192             }
 193             foreach ($this->loggers as $type => $log) {
 194                 if (($type & $levels) && (empty($log[0]) || $replace || $log[0] === $this->bootstrappingLogger)) {
 195                     $log[0] = $logger;
 196                     $loggers[$type] = $log;
 197                 }
 198             }
 199         }
 200
 201         $this->setLoggers($loggers);
 202     }
 203
 204     /**
 205      * Sets a logger for each error level.
 206      *
 207      * @param array $loggers Error levels to [LoggerInterface|null, LogLevel::*] map
 208      *
 209      * @return array The previous map
 210      *
 211      * @throws \InvalidArgumentException
 212      */
 213     public function setLoggers(array $loggers)
 214     {
 215         $prevLogged = $this->loggedErrors;
 216         $prev = $this->loggers;
 217         $flush = array();
 218
 219         foreach ($loggers as $type => $log) {
 220             if (!isset($prev[$type])) {
 221                 throw new \InvalidArgumentException('Unknown error type: '.$type);
 222             }
 223             if (!is_array($log)) {
 224                 $log = array($log);
 225             } elseif (!array_key_exists(0, $log)) {
 226                 throw new \InvalidArgumentException('No logger provided');
 227             }
 228             if (null === $log[0]) {
 229                 $this->loggedErrors &= ~$type;
 230             } elseif ($log[0] instanceof LoggerInterface) {
 231                 $this->loggedErrors |= $type;
 232             } else {
 233                 throw new \InvalidArgumentException('Invalid logger provided');
 234             }
 235             $this->loggers[$type] = $log + $prev[$type];
 236
 237             if ($this->bootstrappingLogger && $prev[$type][0] === $this->bootstrappingLogger) {
 238                 $flush[$type] = $type;
 239             }
 240         }
 241         $this->reRegister($prevLogged | $this->thrownErrors);
 242
 243         if ($flush) {
 244             foreach ($this->bootstrappingLogger->cleanLogs() as $log) {
 245                 $type = $log[2]['exception'] instanceof \ErrorException ? $log[2]['exception']->getSeverity() : E_ERROR;
 246                 if (!isset($flush[$type])) {
 247                     $this->bootstrappingLogger->log($log[0], $log[1], $log[2]);
 248                 } elseif ($this->loggers[$type][0]) {
 249                     $this->loggers[$type][0]->log($this->loggers[$type][1], $log[1], $log[2]);
 250                 }
 251             }
 252         }
 253
 254         return $prev;
 255     }
 256
 257     /**
 258      * Sets a user exception handler.
 259      *
 260      * @param callable $handler A handler that will be called on Exception
 261      *
 262      * @return callable|null The previous exception handler
 263      */
 264     public function setExceptionHandler(callable $handler = null)
 265     {
 266         $prev = $this->exceptionHandler;
 267         $this->exceptionHandler = $handler;
 268
 269         return $prev;
 270     }
 271
 272     /**
 273      * Sets the PHP error levels that throw an exception when a PHP error occurs.
 274      *
 275      * @param int  $levels  A bit field of E_* constants for thrown errors
 276      * @param bool $replace Replace or amend the previous value
 277      *
 278      * @return int The previous value
 279      */
 280     public function throwAt($levels, $replace = false)
 281     {
 282         $prev = $this->thrownErrors;
 283         $this->thrownErrors = ($levels | E_RECOVERABLE_ERROR | E_USER_ERROR) & ~E_USER_DEPRECATED & ~E_DEPRECATED;
 284         if (!$replace) {
 285             $this->thrownErrors |= $prev;
 286         }
 287         $this->reRegister($prev | $this->loggedErrors);
 288
 289         return $prev;
 290     }
 291
 292     /**
 293      * Sets the PHP error levels for which local variables are preserved.
 294      *
 295      * @param int  $levels  A bit field of E_* constants for scoped errors
 296      * @param bool $replace Replace or amend the previous value
 297      *
 298      * @return int The previous value
 299      */
 300     public function scopeAt($levels, $replace = false)
 301     {
 302         $prev = $this->scopedErrors;
 303         $this->scopedErrors = (int) $levels;
 304         if (!$replace) {
 305             $this->scopedErrors |= $prev;
 306         }
 307
 308         return $prev;
 309     }
 310
 311     /**
 312      * Sets the PHP error levels for which the stack trace is preserved.
 313      *
 314      * @param int  $levels  A bit field of E_* constants for traced errors
 315      * @param bool $replace Replace or amend the previous value
 316      *
 317      * @return int The previous value
 318      */
 319     public function traceAt($levels, $replace = false)
 320     {
 321         $prev = $this->tracedErrors;
 322         $this->tracedErrors = (int) $levels;
 323         if (!$replace) {
 324             $this->tracedErrors |= $prev;
 325         }
 326
 327         return $prev;
 328     }
 329
 330     /**
 331      * Sets the error levels where the @-operator is ignored.
 332      *
 333      * @param int  $levels  A bit field of E_* constants for screamed errors
 334      * @param bool $replace Replace or amend the previous value
 335      *
 336      * @return int The previous value
 337      */
 338     public function screamAt($levels, $replace = false)
 339     {
 340         $prev = $this->screamedErrors;
 341         $this->screamedErrors = (int) $levels;
 342         if (!$replace) {
 343             $this->screamedErrors |= $prev;
 344         }
 345
 346         return $prev;
 347     }
 348
 349     /**
 350      * Re-registers as a PHP error handler if levels changed.
 351      */
 352     private function reRegister($prev)
 353     {
 354         if ($prev !== $this->thrownErrors | $this->loggedErrors) {
 355             $handler = set_error_handler('var_dump');
 356             $handler = is_array($handler) ? $handler[0] : null;
 357             restore_error_handler();
 358             if ($handler === $this) {
 359                 restore_error_handler();
 360                 if ($this->isRoot) {
 361                     set_error_handler(array($this, 'handleError'), $this->thrownErrors | $this->loggedErrors);
 362                 } else {
 363                     set_error_handler(array($this, 'handleError'));
 364                 }
 365             }
 366         }
 367     }
 368
 369     /**
 370      * Handles errors by filtering then logging them according to the configured bit fields.
 371      *
 372      * @param int    $type    One of the E_* constants
 373      * @param string $message
 374      * @param string $file
 375      * @param int    $line
 376      *
 377      * @return bool Returns false when no handling happens so that the PHP engine can handle the error itself
 378      *
 379      * @throws \ErrorException When $this->thrownErrors requests so
 380      *
 381      * @internal
 382      */
 383     public function handleError($type, $message, $file, $line)
 384     {
 385         // Level is the current error reporting level to manage silent error.
 386         $level = error_reporting();
 387         $silenced = 0 === ($level & $type);
 388         // Strong errors are not authorized to be silenced.
 389         $level |= E_RECOVERABLE_ERROR | E_USER_ERROR | E_DEPRECATED | E_USER_DEPRECATED;
 390         $log = $this->loggedErrors & $type;
 391         $throw = $this->thrownErrors & $type & $level;
 392         $type &= $level | $this->screamedErrors;
 393
 394         if (!$type || (!$log && !$throw)) {
 395             return !$silenced && $type && $log;
 396         }
 397         $scope = $this->scopedErrors & $type;
 398
 399         if (4 < $numArgs = func_num_args()) {
 400             $context = $scope ? (func_get_arg(4) ?: array()) : array();
 401             $backtrace = 5 < $numArgs ? func_get_arg(5) : null; // defined on HHVM
 402         } else {
 403             $context = array();
 404             $backtrace = null;
 405         }
 406
 407         if (isset($context['GLOBALS']) && $scope) {
 408             $e = $context;                  // Whatever the signature of the method,
 409             unset($e['GLOBALS'], $context); // $context is always a reference in 5.3
 410             $context = $e;
 411         }
 412
 413         if (null !== $backtrace && $type & E_ERROR) {
 414             // E_ERROR fatal errors are triggered on HHVM when
 415             // hhvm.error_handling.call_user_handler_on_fatals=1
 416             // which is the way to get their backtrace.
 417             $this->handleFatalError(compact('type', 'message', 'file', 'line', 'backtrace'));
 418
 419             return true;
 420         }
 421
 422         $logMessage = $this->levels[$type].': '.$message;
 423
 424         if (null !== self::$toStringException) {
 425             $errorAsException = self::$toStringException;
 426             self::$toStringException = null;
 427         } elseif (!$throw && !($type & $level)) {
 428             if (!isset(self::$silencedErrorCache[$id = $file.':'.$line])) {
 429                 $lightTrace = $this->tracedErrors & $type ? $this->cleanTrace(debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 3), $type, $file, $line, false) : array();
 430                 $errorAsException = new SilencedErrorContext($type, $file, $line, $lightTrace);
 431             } elseif (isset(self::$silencedErrorCache[$id][$message])) {
 432                 $lightTrace = null;
 433                 $errorAsException = self::$silencedErrorCache[$id][$message];
 434                 ++$errorAsException->count;
 435             } else {
 436                 $lightTrace = array();
 437                 $errorAsException = null;
 438             }
 439
 440             if (100 < ++self::$silencedErrorCount) {
 441                 self::$silencedErrorCache = $lightTrace = array();
 442                 self::$silencedErrorCount = 1;
 443             }
 444             if ($errorAsException) {
 445                 self::$silencedErrorCache[$id][$message] = $errorAsException;
 446             }
 447             if (null === $lightTrace) {
 448                 return;
 449             }
 450         } else {
 451             if ($scope) {
 452                 $errorAsException = new ContextErrorException($logMessage, 0, $type, $file, $line, $context);
 453             } else {
 454                 $errorAsException = new \ErrorException($logMessage, 0, $type, $file, $line);
 455             }
 456
 457             // Clean the trace by removing function arguments and the first frames added by the error handler itself.
 458             if ($throw || $this->tracedErrors & $type) {
 459                 $backtrace = $backtrace ?: $errorAsException->getTrace();
 460                 $lightTrace = $this->cleanTrace($backtrace, $type, $file, $line, $throw);
 461                 $this->traceReflector->setValue($errorAsException, $lightTrace);
 462             } else {
 463                 $this->traceReflector->setValue($errorAsException, array());
 464             }
 465         }
 466
 467         if ($throw) {
 468             if (E_USER_ERROR & $type) {
 469                 for ($i = 1; isset($backtrace[$i]); ++$i) {
 470                     if (isset($backtrace[$i]['function'], $backtrace[$i]['type'], $backtrace[$i - 1]['function'])
 471                         && '__toString' === $backtrace[$i]['function']
 472                         && '->' === $backtrace[$i]['type']
 473                         && !isset($backtrace[$i - 1]['class'])
 474                         && ('trigger_error' === $backtrace[$i - 1]['function'] || 'user_error' === $backtrace[$i - 1]['function'])
 475                     ) {
 476                         // Here, we know trigger_error() has been called from __toString().
 477                         // HHVM is fine with throwing from __toString() but PHP triggers a fatal error instead.
 478                         // A small convention allows working around the limitation:
 479                         // given a caught $e exception in __toString(), quitting the method with
 480                         // `return trigger_error($e, E_USER_ERROR);` allows this error handler
 481                         // to make $e get through the __toString() barrier.
 482
 483                         foreach ($context as $e) {
 484                             if (($e instanceof \Exception || $e instanceof \Throwable) && $e->__toString() === $message) {
 485                                 if (1 === $i) {
 486                                     // On HHVM
 487                                     $errorAsException = $e;
 488                                     break;
 489                                 }
 490                                 self::$toStringException = $e;
 491
 492                                 return true;
 493                             }
 494                         }
 495
 496                         if (1 < $i) {
 497                             // On PHP (not on HHVM), display the original error message instead of the default one.
 498                             $this->handleException($errorAsException);
 499
 500                             // Stop the process by giving back the error to the native handler.
 501                             return false;
 502                         }
 503                     }
 504                 }
 505             }
 506
 507             throw $errorAsException;
 508         }
 509
 510         if ($this->isRecursive) {
 511             $log = 0;
 512         } elseif (self::$stackedErrorLevels) {
 513             self::$stackedErrors[] = array(
 514                 $this->loggers[$type][0],
 515                 ($type & $level) ? $this->loggers[$type][1] : LogLevel::DEBUG,
 516                 $logMessage,
 517                 $errorAsException ? array('exception' => $errorAsException) : array(),
 518             );
 519         } else {
 520             try {
 521                 $this->isRecursive = true;
 522                 $level = ($type & $level) ? $this->loggers[$type][1] : LogLevel::DEBUG;
 523                 $this->loggers[$type][0]->log($level, $logMessage, $errorAsException ? array('exception' => $errorAsException) : array());
 524             } finally {
 525                 $this->isRecursive = false;
 526             }
 527         }
 528
 529         return !$silenced && $type && $log;
 530     }
 531
 532     /**
 533      * Handles an exception by logging then forwarding it to another handler.
 534      *
 535      * @param \Exception|\Throwable $exception An exception to handle
 536      * @param array                 $error     An array as returned by error_get_last()
 537      *
 538      * @internal
 539      */
 540     public function handleException($exception, array $error = null)
 541     {
 542         if (null === $error) {
 543             self::$exitCode = 255;
 544         }
 545         if (!$exception instanceof \Exception) {
 546             $exception = new FatalThrowableError($exception);
 547         }
 548         $type = $exception instanceof FatalErrorException ? $exception->getSeverity() : E_ERROR;
 549         $handlerException = null;
 550
 551         if (($this->loggedErrors & $type) || $exception instanceof FatalThrowableError) {
 552             if ($exception instanceof FatalErrorException) {
 553                 if ($exception instanceof FatalThrowableError) {
 554                     $error = array(
 555                         'type' => $type,
 556                         'message' => $message = $exception->getMessage(),
 557                         'file' => $exception->getFile(),
 558                         'line' => $exception->getLine(),
 559                     );
 560                 } else {
 561                     $message = 'Fatal '.$exception->getMessage();
 562                 }
 563             } elseif ($exception instanceof \ErrorException) {
 564                 $message = 'Uncaught '.$exception->getMessage();
 565             } else {
 566                 $message = 'Uncaught Exception: '.$exception->getMessage();
 567             }
 568         }
 569         if ($this->loggedErrors & $type) {
 570             try {
 571                 $this->loggers[$type][0]->log($this->loggers[$type][1], $message, array('exception' => $exception));
 572             } catch (\Exception $handlerException) {
 573             } catch (\Throwable $handlerException) {
 574             }
 575         }
 576         if ($exception instanceof FatalErrorException && !$exception instanceof OutOfMemoryException && $error) {
 577             foreach ($this->getFatalErrorHandlers() as $handler) {
 578                 if ($e = $handler->handleError($error, $exception)) {
 579                     $exception = $e;
 580                     break;
 581                 }
 582             }
 583         }
 584         $exceptionHandler = $this->exceptionHandler;
 585         $this->exceptionHandler = null;
 586         try {
 587             if (null !== $exceptionHandler) {
 588                 return \call_user_func($exceptionHandler, $exception);
 589             }
 590             $handlerException = $handlerException ?: $exception;
 591         } catch (\Exception $handlerException) {
 592         } catch (\Throwable $handlerException) {
 593         }
 594         if ($exception === $handlerException) {
 595             self::$reservedMemory = null; // Disable the fatal error handler
 596             throw $exception; // Give back $exception to the native handler
 597         }
 598         $this->handleException($handlerException);
 599     }
 600
 601     /**
 602      * Shutdown registered function for handling PHP fatal errors.
 603      *
 604      * @param array $error An array as returned by error_get_last()
 605      *
 606      * @internal
 607      */
 608     public static function handleFatalError(array $error = null)
 609     {
 610         if (null === self::$reservedMemory) {
 611             return;
 612         }
 613
 614         $handler = self::$reservedMemory = null;
 615         $handlers = array();
 616         $previousHandler = null;
 617         $sameHandlerLimit = 10;
 618
 619         while (!is_array($handler) || !$handler[0] instanceof self) {
 620             $handler = set_exception_handler('var_dump');
 621             restore_exception_handler();
 622
 623             if (!$handler) {
 624                 break;
 625             }
 626             restore_exception_handler();
 627
 628             if ($handler !== $previousHandler) {
 629                 array_unshift($handlers, $handler);
 630                 $previousHandler = $handler;
 631             } elseif (0 === --$sameHandlerLimit) {
 632                 $handler = null;
 633                 break;
 634             }
 635         }
 636         foreach ($handlers as $h) {
 637             set_exception_handler($h);
 638         }
 639         if (!$handler) {
 640             return;
 641         }
 642         if ($handler !== $h) {
 643             $handler[0]->setExceptionHandler($h);
 644         }
 645         $handler = $handler[0];
 646         $handlers = array();
 647
 648         if ($exit = null === $error) {
 649             $error = error_get_last();
 650         }
 651
 652         try {
 653             while (self::$stackedErrorLevels) {
 654                 static::unstackErrors();
 655             }
 656         } catch (\Exception $exception) {
 657             // Handled below
 658         } catch (\Throwable $exception) {
 659             // Handled below
 660         }
 661
 662         if ($error && $error['type'] &= E_PARSE | E_ERROR | E_CORE_ERROR | E_COMPILE_ERROR) {
 663             // Let's not throw anymore but keep logging
 664             $handler->throwAt(0, true);
 665             $trace = isset($error['backtrace']) ? $error['backtrace'] : null;
 666
 667             if (0 === strpos($error['message'], 'Allowed memory') || 0 === strpos($error['message'], 'Out of memory')) {
 668                 $exception = new OutOfMemoryException($handler->levels[$error['type']].': '.$error['message'], 0, $error['type'], $error['file'], $error['line'], 2, false, $trace);
 669             } else {
 670                 $exception = new FatalErrorException($handler->levels[$error['type']].': '.$error['message'], 0, $error['type'], $error['file'], $error['line'], 2, true, $trace);
 671             }
 672         }
 673
 674         try {
 675             if (isset($exception)) {
 676                 self::$exitCode = 255;
 677                 $handler->handleException($exception, $error);
 678             }
 679         } catch (FatalErrorException $e) {
 680             // Ignore this re-throw
 681         }
 682
 683         if ($exit && self::$exitCode) {
 684             $exitCode = self::$exitCode;
 685             register_shutdown_function('register_shutdown_function', function () use ($exitCode) { exit($exitCode); });
 686         }
 687     }
 688
 689     /**
 690      * Configures the error handler for delayed handling.
 691      * Ensures also that non-catchable fatal errors are never silenced.
 692      *
 693      * As shown by http://bugs.php.net/42098 and http://bugs.php.net/60724
 694      * PHP has a compile stage where it behaves unusually. To workaround it,
 695      * we plug an error handler that only stacks errors for later.
 696      *
 697      * The most important feature of this is to prevent
 698      * autoloading until unstackErrors() is called.
 699      *
 700      * @deprecated since version 3.4, to be removed in 4.0.
 701      */
 702     public static function stackErrors()
 703     {
 704         @trigger_error('Support for stacking errors is deprecated since Symfony 3.4 and will be removed in 4.0.', E_USER_DEPRECATED);
 705
 706         self::$stackedErrorLevels[] = error_reporting(error_reporting() | E_PARSE | E_ERROR | E_CORE_ERROR | E_COMPILE_ERROR);
 707     }
 708
 709     /**
 710      * Unstacks stacked errors and forwards to the logger.
 711      *
 712      * @deprecated since version 3.4, to be removed in 4.0.
 713      */
 714     public static function unstackErrors()
 715     {
 716         @trigger_error('Support for unstacking errors is deprecated since Symfony 3.4 and will be removed in 4.0.', E_USER_DEPRECATED);
 717
 718         $level = array_pop(self::$stackedErrorLevels);
 719
 720         if (null !== $level) {
 721             $errorReportingLevel = error_reporting($level);
 722             if ($errorReportingLevel !== ($level | E_PARSE | E_ERROR | E_CORE_ERROR | E_COMPILE_ERROR)) {
 723                 // If the user changed the error level, do not overwrite it
 724                 error_reporting($errorReportingLevel);
 725             }
 726         }
 727
 728         if (empty(self::$stackedErrorLevels)) {
 729             $errors = self::$stackedErrors;
 730             self::$stackedErrors = array();
 731
 732             foreach ($errors as $error) {
 733                 $error[0]->log($error[1], $error[2], $error[3]);
 734             }
 735         }
 736     }
 737
 738     /**
 739      * Gets the fatal error handlers.
 740      *
 741      * Override this method if you want to define more fatal error handlers.
 742      *
 743      * @return FatalErrorHandlerInterface[] An array of FatalErrorHandlerInterface
 744      */
 745     protected function getFatalErrorHandlers()
 746     {
 747         return array(
 748             new UndefinedFunctionFatalErrorHandler(),
 749             new UndefinedMethodFatalErrorHandler(),
 750             new ClassNotFoundFatalErrorHandler(),
 751         );
 752     }
 753
 754     private function cleanTrace($backtrace, $type, $file, $line, $throw)
 755     {
 756         $lightTrace = $backtrace;
 757
 758         for ($i = 0; isset($backtrace[$i]); ++$i) {
 759             if (isset($backtrace[$i]['file'], $backtrace[$i]['line']) && $backtrace[$i]['line'] === $line && $backtrace[$i]['file'] === $file) {
 760                 $lightTrace = array_slice($lightTrace, 1 + $i);
 761                 break;
 762             }
 763         }
 764         if (!($throw || $this->scopedErrors & $type)) {
 765             for ($i = 0; isset($lightTrace[$i]); ++$i) {
 766                 unset($lightTrace[$i]['args'], $lightTrace[$i]['object']);
 767             }
 768         }
 769
 770         return $lightTrace;
 771     }
 772 }