[Summary view] [Print] [Text view]

   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\LoggerInterface;
  15  use Psr\Log\LogLevel;
  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\ClassNotFoundFatalErrorHandler;
  22  use Symfony\Component\Debug\FatalErrorHandler\FatalErrorHandlerInterface;
  23  use Symfony\Component\Debug\FatalErrorHandler\UndefinedFunctionFatalErrorHandler;
  24  use Symfony\Component\Debug\FatalErrorHandler\UndefinedMethodFatalErrorHandler;
  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 = [
  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 = [
  70          \E_DEPRECATED => [null, LogLevel::INFO],
  71          \E_USER_DEPRECATED => [null, LogLevel::INFO],
  72          \E_NOTICE => [null, LogLevel::WARNING],
  73          \E_USER_NOTICE => [null, LogLevel::WARNING],
  74          \E_STRICT => [null, LogLevel::WARNING],
  75          \E_WARNING => [null, LogLevel::WARNING],
  76          \E_USER_WARNING => [null, LogLevel::WARNING],
  77          \E_COMPILE_WARNING => [null, LogLevel::WARNING],
  78          \E_CORE_WARNING => [null, LogLevel::WARNING],
  79          \E_USER_ERROR => [null, LogLevel::CRITICAL],
  80          \E_RECOVERABLE_ERROR => [null, LogLevel::CRITICAL],
  81          \E_COMPILE_ERROR => [null, LogLevel::CRITICAL],
  82          \E_PARSE => [null, LogLevel::CRITICAL],
  83          \E_ERROR => [null, LogLevel::CRITICAL],
  84          \E_CORE_ERROR => [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 = [];
 101      private static $stackedErrorLevels = [];
 102      private static $toStringException = null;
 103      private static $silencedErrorCache = [];
 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 === $prev = set_error_handler([$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([$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([$handler, 'handleException'])) && $prev[0] instanceof self) {
 144              restore_exception_handler();
 145              if (!$handlerIsRegistered) {
 146                  $handler = $prev[0];
 147              } elseif ($handler !== $prev[0] && $replace) {
 148                  set_exception_handler([$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          $loggers = [];
 182  
 183          if (\is_array($levels)) {
 184              foreach ($levels as $type => $logLevel) {
 185                  if (empty($this->loggers[$type][0]) || $replace || $this->loggers[$type][0] === $this->bootstrappingLogger) {
 186                      $loggers[$type] = [$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          $flush = [];
 218  
 219          foreach ($loggers as $type => $log) {
 220              if (!isset($prev[$type])) {
 221                  throw new \InvalidArgumentException('Unknown error type: '.$type);
 222              }
 223              if (!\is_array($log)) {
 224                  $log = [$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([$this, 'handleError'], $this->thrownErrors | $this->loggedErrors);
 362                  } else {
 363                      set_error_handler([$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          if (\PHP_VERSION_ID >= 70300 && \E_WARNING === $type && '"' === $message[0] && false !== strpos($message, '" targeting switch is equivalent to "break')) {
 386              $type = \E_DEPRECATED;
 387          }
 388  
 389          // Level is the current error reporting level to manage silent error.
 390          $level = error_reporting();
 391          $silenced = 0 === ($level & $type);
 392          // Strong errors are not authorized to be silenced.
 393          $level |= \E_RECOVERABLE_ERROR | \E_USER_ERROR | \E_DEPRECATED | \E_USER_DEPRECATED;
 394          $log = $this->loggedErrors & $type;
 395          $throw = $this->thrownErrors & $type & $level;
 396          $type &= $level | $this->screamedErrors;
 397  
 398          if (!$type || (!$log && !$throw)) {
 399              return !$silenced && $type && $log;
 400          }
 401          $scope = $this->scopedErrors & $type;
 402  
 403          if (4 < $numArgs = \func_num_args()) {
 404              $context = func_get_arg(4) ?: [];
 405              $backtrace = 5 < $numArgs ? func_get_arg(5) : null; // defined on HHVM
 406          } else {
 407              $context = [];
 408              $backtrace = null;
 409          }
 410  
 411          if (isset($context['GLOBALS']) && $scope) {
 412              $e = $context;                  // Whatever the signature of the method,
 413              unset($e['GLOBALS'], $context); // $context is always a reference in 5.3
 414              $context = $e;
 415          }
 416  
 417          if (null !== $backtrace && $type & \E_ERROR) {
 418              // E_ERROR fatal errors are triggered on HHVM when
 419              // hhvm.error_handling.call_user_handler_on_fatals=1
 420              // which is the way to get their backtrace.
 421              $this->handleFatalError(compact('type', 'message', 'file', 'line', 'backtrace'));
 422  
 423              return true;
 424          }
 425  
 426          $logMessage = $this->levels[$type].': '.$message;
 427  
 428          if (null !== self::$toStringException) {
 429              $errorAsException = self::$toStringException;
 430              self::$toStringException = null;
 431          } elseif (!$throw && !($type & $level)) {
 432              if (!isset(self::$silencedErrorCache[$id = $file.':'.$line])) {
 433                  $lightTrace = $this->tracedErrors & $type ? $this->cleanTrace(debug_backtrace(\DEBUG_BACKTRACE_IGNORE_ARGS, 3), $type, $file, $line, false) : [];
 434                  $errorAsException = new SilencedErrorContext($type, $file, $line, $lightTrace);
 435              } elseif (isset(self::$silencedErrorCache[$id][$message])) {
 436                  $lightTrace = null;
 437                  $errorAsException = self::$silencedErrorCache[$id][$message];
 438                  ++$errorAsException->count;
 439              } else {
 440                  $lightTrace = [];
 441                  $errorAsException = null;
 442              }
 443  
 444              if (100 < ++self::$silencedErrorCount) {
 445                  self::$silencedErrorCache = $lightTrace = [];
 446                  self::$silencedErrorCount = 1;
 447              }
 448              if ($errorAsException) {
 449                  self::$silencedErrorCache[$id][$message] = $errorAsException;
 450              }
 451              if (null === $lightTrace) {
 452                  return true;
 453              }
 454          } else {
 455              if ($scope) {
 456                  $errorAsException = new ContextErrorException($logMessage, 0, $type, $file, $line, $context);
 457              } else {
 458                  $errorAsException = new \ErrorException($logMessage, 0, $type, $file, $line);
 459              }
 460  
 461              // Clean the trace by removing function arguments and the first frames added by the error handler itself.
 462              if ($throw || $this->tracedErrors & $type) {
 463                  $backtrace = $backtrace ?: $errorAsException->getTrace();
 464                  $lightTrace = $this->cleanTrace($backtrace, $type, $file, $line, $throw);
 465                  $this->traceReflector->setValue($errorAsException, $lightTrace);
 466              } else {
 467                  $this->traceReflector->setValue($errorAsException, []);
 468              }
 469          }
 470  
 471          if ($throw) {
 472              if (\PHP_VERSION_ID < 70400 && \E_USER_ERROR & $type) {
 473                  for ($i = 1; isset($backtrace[$i]); ++$i) {
 474                      if (isset($backtrace[$i]['function'], $backtrace[$i]['type'], $backtrace[$i - 1]['function'])
 475                          && '__toString' === $backtrace[$i]['function']
 476                          && '->' === $backtrace[$i]['type']
 477                          && !isset($backtrace[$i - 1]['class'])
 478                          && ('trigger_error' === $backtrace[$i - 1]['function'] || 'user_error' === $backtrace[$i - 1]['function'])
 479                      ) {
 480                          // Here, we know trigger_error() has been called from __toString().
 481                          // HHVM is fine with throwing from __toString() but PHP triggers a fatal error instead.
 482                          // A small convention allows working around the limitation:
 483                          // given a caught $e exception in __toString(), quitting the method with
 484                          // `return trigger_error($e, E_USER_ERROR);` allows this error handler
 485                          // to make $e get through the __toString() barrier.
 486  
 487                          foreach ($context as $e) {
 488                              if (($e instanceof \Exception || $e instanceof \Throwable) && $e->__toString() === $message) {
 489                                  if (1 === $i) {
 490                                      // On HHVM
 491                                      $errorAsException = $e;
 492                                      break;
 493                                  }
 494                                  self::$toStringException = $e;
 495  
 496                                  return true;
 497                              }
 498                          }
 499  
 500                          if (1 < $i) {
 501                              // On PHP (not on HHVM), display the original error message instead of the default one.
 502                              $this->handleException($errorAsException);
 503  
 504                              // Stop the process by giving back the error to the native handler.
 505                              return false;
 506                          }
 507                      }
 508                  }
 509              }
 510  
 511              throw $errorAsException;
 512          }
 513  
 514          if ($this->isRecursive) {
 515              $log = 0;
 516          } elseif (self::$stackedErrorLevels) {
 517              self::$stackedErrors[] = [
 518                  $this->loggers[$type][0],
 519                  ($type & $level) ? $this->loggers[$type][1] : LogLevel::DEBUG,
 520                  $logMessage,
 521                  $errorAsException ? ['exception' => $errorAsException] : [],
 522              ];
 523          } else {
 524              if (\PHP_VERSION_ID < (\PHP_VERSION_ID < 70400 ? 70316 : 70404) && !\defined('HHVM_VERSION')) {
 525                  $currentErrorHandler = set_error_handler('var_dump');
 526                  restore_error_handler();
 527              }
 528  
 529              try {
 530                  $this->isRecursive = true;
 531                  $level = ($type & $level) ? $this->loggers[$type][1] : LogLevel::DEBUG;
 532                  $this->loggers[$type][0]->log($level, $logMessage, $errorAsException ? ['exception' => $errorAsException] : []);
 533              } finally {
 534                  $this->isRecursive = false;
 535  
 536                  if (\PHP_VERSION_ID < (\PHP_VERSION_ID < 70400 ? 70316 : 70404) && !\defined('HHVM_VERSION')) {
 537                      set_error_handler($currentErrorHandler);
 538                  }
 539              }
 540          }
 541  
 542          return !$silenced && $type && $log;
 543      }
 544  
 545      /**
 546       * Handles an exception by logging then forwarding it to another handler.
 547       *
 548       * @param \Exception|\Throwable $exception An exception to handle
 549       * @param array                 $error     An array as returned by error_get_last()
 550       *
 551       * @internal
 552       */
 553      public function handleException($exception, array $error = null)
 554      {
 555          if (null === $error) {
 556              self::$exitCode = 255;
 557          }
 558          if (!$exception instanceof \Exception) {
 559              $exception = new FatalThrowableError($exception);
 560          }
 561          $type = $exception instanceof FatalErrorException ? $exception->getSeverity() : \E_ERROR;
 562          $handlerException = null;
 563  
 564          if (($this->loggedErrors & $type) || $exception instanceof FatalThrowableError) {
 565              if ($exception instanceof FatalErrorException) {
 566                  if ($exception instanceof FatalThrowableError) {
 567                      $error = [
 568                          'type' => $type,
 569                          'message' => $message = $exception->getMessage(),
 570                          'file' => $exception->getFile(),
 571                          'line' => $exception->getLine(),
 572                      ];
 573                  } else {
 574                      $message = 'Fatal '.$exception->getMessage();
 575                  }
 576              } elseif ($exception instanceof \ErrorException) {
 577                  $message = 'Uncaught '.$exception->getMessage();
 578              } else {
 579                  $message = 'Uncaught Exception: '.$exception->getMessage();
 580              }
 581          }
 582          if ($this->loggedErrors & $type) {
 583              try {
 584                  $this->loggers[$type][0]->log($this->loggers[$type][1], $message, ['exception' => $exception]);
 585              } catch (\Exception $handlerException) {
 586              } catch (\Throwable $handlerException) {
 587              }
 588          }
 589          if ($exception instanceof FatalErrorException && !$exception instanceof OutOfMemoryException && $error) {
 590              foreach ($this->getFatalErrorHandlers() as $handler) {
 591                  if ($e = $handler->handleError($error, $exception)) {
 592                      $exception = $e;
 593                      break;
 594                  }
 595              }
 596          }
 597          $exceptionHandler = $this->exceptionHandler;
 598          $this->exceptionHandler = null;
 599          try {
 600              if (null !== $exceptionHandler) {
 601                  $exceptionHandler($exception);
 602  
 603                  return;
 604              }
 605              $handlerException = $handlerException ?: $exception;
 606          } catch (\Exception $handlerException) {
 607          } catch (\Throwable $handlerException) {
 608          }
 609          if ($exception === $handlerException) {
 610              self::$reservedMemory = null; // Disable the fatal error handler
 611              throw $exception; // Give back $exception to the native handler
 612          }
 613          $this->handleException($handlerException);
 614      }
 615  
 616      /**
 617       * Shutdown registered function for handling PHP fatal errors.
 618       *
 619       * @param array $error An array as returned by error_get_last()
 620       *
 621       * @internal
 622       */
 623      public static function handleFatalError(array $error = null)
 624      {
 625          if (null === self::$reservedMemory) {
 626              return;
 627          }
 628  
 629          $handler = self::$reservedMemory = null;
 630          $handlers = [];
 631          $previousHandler = null;
 632          $sameHandlerLimit = 10;
 633  
 634          while (!\is_array($handler) || !$handler[0] instanceof self) {
 635              $handler = set_exception_handler('var_dump');
 636              restore_exception_handler();
 637  
 638              if (!$handler) {
 639                  break;
 640              }
 641              restore_exception_handler();
 642  
 643              if ($handler !== $previousHandler) {
 644                  array_unshift($handlers, $handler);
 645                  $previousHandler = $handler;
 646              } elseif (0 === --$sameHandlerLimit) {
 647                  $handler = null;
 648                  break;
 649              }
 650          }
 651          foreach ($handlers as $h) {
 652              set_exception_handler($h);
 653          }
 654          if (!$handler) {
 655              return;
 656          }
 657          if ($handler !== $h) {
 658              $handler[0]->setExceptionHandler($h);
 659          }
 660          $handler = $handler[0];
 661          $handlers = [];
 662  
 663          if ($exit = null === $error) {
 664              $error = error_get_last();
 665          }
 666  
 667          try {
 668              while (self::$stackedErrorLevels) {
 669                  static::unstackErrors();
 670              }
 671          } catch (\Exception $exception) {
 672              // Handled below
 673          } catch (\Throwable $exception) {
 674              // Handled below
 675          }
 676  
 677          if ($error && $error['type'] &= \E_PARSE | \E_ERROR | \E_CORE_ERROR | \E_COMPILE_ERROR) {
 678              // Let's not throw anymore but keep logging
 679              $handler->throwAt(0, true);
 680              $trace = isset($error['backtrace']) ? $error['backtrace'] : null;
 681  
 682              if (0 === strpos($error['message'], 'Allowed memory') || 0 === strpos($error['message'], 'Out of memory')) {
 683                  $exception = new OutOfMemoryException($handler->levels[$error['type']].': '.$error['message'], 0, $error['type'], $error['file'], $error['line'], 2, false, $trace);
 684              } else {
 685                  $exception = new FatalErrorException($handler->levels[$error['type']].': '.$error['message'], 0, $error['type'], $error['file'], $error['line'], 2, true, $trace);
 686              }
 687          }
 688  
 689          try {
 690              if (isset($exception)) {
 691                  self::$exitCode = 255;
 692                  $handler->handleException($exception, $error);
 693              }
 694          } catch (FatalErrorException $e) {
 695              // Ignore this re-throw
 696          }
 697  
 698          if ($exit && self::$exitCode) {
 699              $exitCode = self::$exitCode;
 700              register_shutdown_function('register_shutdown_function', function () use ($exitCode) { exit($exitCode); });
 701          }
 702      }
 703  
 704      /**
 705       * Configures the error handler for delayed handling.
 706       * Ensures also that non-catchable fatal errors are never silenced.
 707       *
 708       * As shown by http://bugs.php.net/42098 and http://bugs.php.net/60724
 709       * PHP has a compile stage where it behaves unusually. To workaround it,
 710       * we plug an error handler that only stacks errors for later.
 711       *
 712       * The most important feature of this is to prevent
 713       * autoloading until unstackErrors() is called.
 714       *
 715       * @deprecated since version 3.4, to be removed in 4.0.
 716       */
 717      public static function stackErrors()
 718      {
 719          @trigger_error('Support for stacking errors is deprecated since Symfony 3.4 and will be removed in 4.0.', \E_USER_DEPRECATED);
 720  
 721          self::$stackedErrorLevels[] = error_reporting(error_reporting() | \E_PARSE | \E_ERROR | \E_CORE_ERROR | \E_COMPILE_ERROR);
 722      }
 723  
 724      /**
 725       * Unstacks stacked errors and forwards to the logger.
 726       *
 727       * @deprecated since version 3.4, to be removed in 4.0.
 728       */
 729      public static function unstackErrors()
 730      {
 731          @trigger_error('Support for unstacking errors is deprecated since Symfony 3.4 and will be removed in 4.0.', \E_USER_DEPRECATED);
 732  
 733          $level = array_pop(self::$stackedErrorLevels);
 734  
 735          if (null !== $level) {
 736              $errorReportingLevel = error_reporting($level);
 737              if ($errorReportingLevel !== ($level | \E_PARSE | \E_ERROR | \E_CORE_ERROR | \E_COMPILE_ERROR)) {
 738                  // If the user changed the error level, do not overwrite it
 739                  error_reporting($errorReportingLevel);
 740              }
 741          }
 742  
 743          if (empty(self::$stackedErrorLevels)) {
 744              $errors = self::$stackedErrors;
 745              self::$stackedErrors = [];
 746  
 747              foreach ($errors as $error) {
 748                  $error[0]->log($error[1], $error[2], $error[3]);
 749              }
 750          }
 751      }
 752  
 753      /**
 754       * Gets the fatal error handlers.
 755       *
 756       * Override this method if you want to define more fatal error handlers.
 757       *
 758       * @return FatalErrorHandlerInterface[] An array of FatalErrorHandlerInterface
 759       */
 760      protected function getFatalErrorHandlers()
 761      {
 762          return [
 763              new UndefinedFunctionFatalErrorHandler(),
 764              new UndefinedMethodFatalErrorHandler(),
 765              new ClassNotFoundFatalErrorHandler(),
 766          ];
 767      }
 768  
 769      private function cleanTrace($backtrace, $type, $file, $line, $throw)
 770      {
 771          $lightTrace = $backtrace;
 772  
 773          for ($i = 0; isset($backtrace[$i]); ++$i) {
 774              if (isset($backtrace[$i]['file'], $backtrace[$i]['line']) && $backtrace[$i]['line'] === $line && $backtrace[$i]['file'] === $file) {
 775                  $lightTrace = \array_slice($lightTrace, 1 + $i);
 776                  break;
 777              }
 778          }
 779          if (!($throw || $this->scopedErrors & $type)) {
 780              for ($i = 0; isset($lightTrace[$i]); ++$i) {
 781                  unset($lightTrace[$i]['args'], $lightTrace[$i]['object']);
 782              }
 783          }
 784  
 785          return $lightTrace;
 786      }
 787  }