includes/Exception.php

   1 <?php
   2 /**
   3  * Exception class and handler.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * @defgroup Exception Exception
  25  */
  26
  27 /**
  28  * MediaWiki exception
  29  *
  30  * @ingroup Exception
  31  */
  32 class MWException extends Exception {
  33         /**
  34          * Should the exception use $wgOut to output the error?
  35          *
  36          * @return bool
  37          */
  38         function useOutputPage() {
  39                 return $this->useMessageCache() &&
  40                         !empty( $GLOBALS['wgFullyInitialised'] ) &&
  41                         !empty( $GLOBALS['wgOut'] ) &&
  42                         !empty( $GLOBALS['wgTitle'] );
  43         }
  44
  45         /**
  46          * Whether to log this exception in the exception debug log.
  47          *
  48          * @since 1.23
  49          * @return boolean
  50          */
  51         function isLoggable() {
  52                 return true;
  53         }
  54
  55         /**
  56          * Can the extension use the Message class/wfMessage to get i18n-ed messages?
  57          *
  58          * @return bool
  59          */
  60         function useMessageCache() {
  61                 global $wgLang;
  62
  63                 foreach ( $this->getTrace() as $frame ) {
  64                         if ( isset( $frame['class'] ) && $frame['class'] === 'LocalisationCache' ) {
  65                                 return false;
  66                         }
  67                 }
  68
  69                 return $wgLang instanceof Language;
  70         }
  71
  72         /**
  73          * Run hook to allow extensions to modify the text of the exception
  74          *
  75          * @param string $name class name of the exception
  76          * @param array $args arguments to pass to the callback functions
  77          * @return string|null string to output or null if any hook has been called
  78          */
  79         function runHooks( $name, $args = array() ) {
  80                 global $wgExceptionHooks;
  81
  82                 if ( !isset( $wgExceptionHooks ) || !is_array( $wgExceptionHooks ) ) {
  83                         return null; // Just silently ignore
  84                 }
  85
  86                 if ( !array_key_exists( $name, $wgExceptionHooks ) ||
  87                         !is_array( $wgExceptionHooks[$name] )
  88                 ) {
  89                         return null;
  90                 }
  91
  92                 $hooks = $wgExceptionHooks[$name];
  93                 $callargs = array_merge( array( $this ), $args );
  94
  95                 foreach ( $hooks as $hook ) {
  96                         if (
  97                                 is_string( $hook ) ||
  98                                 ( is_array( $hook ) && count( $hook ) >= 2 && is_string( $hook[0] ) )
  99                         ) {
 100                                 // 'function' or array( 'class', hook' )
 101                                 $result = call_user_func_array( $hook, $callargs );
 102                         } else {
 103                                 $result = null;
 104                         }
 105
 106                         if ( is_string( $result ) ) {
 107                                 return $result;
 108                         }
 109                 }
 110                 return null;
 111         }
 112
 113         /**
 114          * Get a message from i18n
 115          *
 116          * @param string $key message name
 117          * @param string $fallback default message if the message cache can't be
 118          *                  called by the exception
 119          * The function also has other parameters that are arguments for the message
 120          * @return string message with arguments replaced
 121          */
 122         function msg( $key, $fallback /*[, params...] */ ) {
 123                 $args = array_slice( func_get_args(), 2 );
 124
 125                 if ( $this->useMessageCache() ) {
 126                         return wfMessage( $key, $args )->plain();
 127                 } else {
 128                         return wfMsgReplaceArgs( $fallback, $args );
 129                 }
 130         }
 131
 132         /**
 133          * If $wgShowExceptionDetails is true, return a HTML message with a
 134          * backtrace to the error, otherwise show a message to ask to set it to true
 135          * to show that information.
 136          *
 137          * @return string html to output
 138          */
 139         function getHTML() {
 140                 global $wgShowExceptionDetails;
 141
 142                 if ( $wgShowExceptionDetails ) {
 143                         return '<p>' . nl2br( htmlspecialchars( $this->getMessage() ) ) .
 144                                 '</p><p>Backtrace:</p><p>' .
 145                                 nl2br( htmlspecialchars( MWExceptionHandler::formatRedactedTrace( $this ) ) ) .
 146                                 "</p>\n";
 147                 } else {
 148                         return "<div class=\"errorbox\">" .
 149                                 '[' . MWExceptionHandler::getLogId( $this ) . '] ' .
 150                                 gmdate( 'Y-m-d H:i:s' ) .
 151                                 ": Fatal exception of type " . get_class( $this ) . "</div>\n" .
 152                                 "<!-- Set \$wgShowExceptionDetails = true; " .
 153                                 "at the bottom of LocalSettings.php to show detailed " .
 154                                 "debugging information. -->";
 155                 }
 156         }
 157
 158         /**
 159          * Get the text to display when reporting the error on the command line.
 160          * If $wgShowExceptionDetails is true, return a text message with a
 161          * backtrace to the error.
 162          *
 163          * @return string
 164          */
 165         function getText() {
 166                 global $wgShowExceptionDetails;
 167
 168                 if ( $wgShowExceptionDetails ) {
 169                         return $this->getMessage() .
 170                                 "\nBacktrace:\n" . MWExceptionHandler::formatRedactedTrace( $this ) . "\n";
 171                 } else {
 172                         return "Set \$wgShowExceptionDetails = true; " .
 173                                 "in LocalSettings.php to show detailed debugging information.\n";
 174                 }
 175         }
 176
 177         /**
 178          * Return the title of the page when reporting this error in a HTTP response.
 179          *
 180          * @return string
 181          */
 182         function getPageTitle() {
 183                 global $wgSitename;
 184                 return $this->msg( 'pagetitle', "$1 - $wgSitename", $this->msg( 'internalerror', 'Internal error' ) );
 185         }
 186
 187         /**
 188          * Get a the ID for this error.
 189          *
 190          * @since 1.20
 191          * @deprecated since 1.22 Use MWExceptionHandler::getLogId instead.
 192          * @return string
 193          */
 194         function getLogId() {
 195                 wfDeprecated( __METHOD__, '1.22' );
 196                 return MWExceptionHandler::getLogId( $this );
 197         }
 198
 199         /**
 200          * Return the requested URL and point to file and line number from which the
 201          * exception occurred
 202          *
 203          * @since 1.8
 204          * @deprecated since 1.22 Use MWExceptionHandler::getLogMessage instead.
 205          * @return string
 206          */
 207         function getLogMessage() {
 208                 wfDeprecated( __METHOD__, '1.22' );
 209                 return MWExceptionHandler::getLogMessage( $this );
 210         }
 211
 212         /**
 213          * Output the exception report using HTML.
 214          */
 215         function reportHTML() {
 216                 global $wgOut;
 217                 if ( $this->useOutputPage() ) {
 218                         $wgOut->prepareErrorPage( $this->getPageTitle() );
 219
 220                         $hookResult = $this->runHooks( get_class( $this ) );
 221                         if ( $hookResult ) {
 222                                 $wgOut->addHTML( $hookResult );
 223                         } else {
 224                                 $wgOut->addHTML( $this->getHTML() );
 225                         }
 226
 227                         $wgOut->output();
 228                 } else {
 229                         header( 'Content-Type: text/html; charset=utf-8' );
 230                         echo "<!DOCTYPE html>\n" .
 231                                 '<html><head>' .
 232                                 '<title>' . htmlspecialchars( $this->getPageTitle() ) . '</title>' .
 233                                 '<style>body { font-family: sans-serif; margin: 0; padding: 0.5em 2em; }</style>' .
 234                                 "</head><body>\n";
 235
 236                         $hookResult = $this->runHooks( get_class( $this ) . 'Raw' );
 237                         if ( $hookResult ) {
 238                                 echo $hookResult;
 239                         } else {
 240                                 echo $this->getHTML();
 241                         }
 242
 243                         echo "</body></html>\n";
 244                 }
 245         }
 246
 247         /**
 248          * Output a report about the exception and takes care of formatting.
 249          * It will be either HTML or plain text based on isCommandLine().
 250          */
 251         function report() {
 252                 global $wgMimeType;
 253
 254                 MWExceptionHandler::logException( $this );
 255
 256                 if ( defined( 'MW_API' ) ) {
 257                         // Unhandled API exception, we can't be sure that format printer is alive
 258                         header( 'MediaWiki-API-Error: internal_api_error_' . get_class( $this ) );
 259                         wfHttpError( 500, 'Internal Server Error', $this->getText() );
 260                 } elseif ( self::isCommandLine() ) {
 261                         MWExceptionHandler::printError( $this->getText() );
 262                 } else {
 263                         header( 'HTTP/1.1 500 MediaWiki exception' );
 264                         header( 'Status: 500 MediaWiki exception', true );
 265                         header( "Content-Type: $wgMimeType; charset=utf-8", true );
 266
 267                         $this->reportHTML();
 268                 }
 269         }
 270
 271         /**
 272          * Check whether we are in command line mode or not to report the exception
 273          * in the correct format.
 274          *
 275          * @return bool
 276          */
 277         static function isCommandLine() {
 278                 return !empty( $GLOBALS['wgCommandLineMode'] );
 279         }
 280 }
 281
 282 /**
 283  * Exception class which takes an HTML error message, and does not
 284  * produce a backtrace. Replacement for OutputPage::fatalError().
 285  *
 286  * @since 1.7
 287  * @ingroup Exception
 288  */
 289 class FatalError extends MWException {
 290
 291         /**
 292          * @return string
 293          */
 294         function getHTML() {
 295                 return $this->getMessage();
 296         }
 297
 298         /**
 299          * @return string
 300          */
 301         function getText() {
 302                 return $this->getMessage();
 303         }
 304 }
 305
 306 /**
 307  * An error page which can definitely be safely rendered using the OutputPage.
 308  *
 309  * @since 1.7
 310  * @ingroup Exception
 311  */
 312 class ErrorPageError extends MWException {
 313         public $title, $msg, $params;
 314
 315         /**
 316          * Note: these arguments are keys into wfMessage(), not text!
 317          *
 318          * @param string|Message $title Message key (string) for page title, or a Message object
 319          * @param string|Message $msg Message key (string) for error text, or a Message object
 320          * @param array $params with parameters to wfMessage()
 321          */
 322         function __construct( $title, $msg, $params = null ) {
 323                 $this->title = $title;
 324                 $this->msg = $msg;
 325                 $this->params = $params;
 326
 327                 // Bug 44111: Messages in the log files should be in English and not
 328                 // customized by the local wiki. So get the default English version for
 329                 // passing to the parent constructor. Our overridden report() below
 330                 // makes sure that the page shown to the user is not forced to English.
 331                 if ( $msg instanceof Message ) {
 332                         $enMsg = clone( $msg );
 333                 } else {
 334                         $enMsg = wfMessage( $msg, $params );
 335                 }
 336                 $enMsg->inLanguage( 'en' )->useDatabase( false );
 337                 parent::__construct( $enMsg->text() );
 338         }
 339
 340         function report() {
 341                 global $wgOut;
 342
 343                 $wgOut->showErrorPage( $this->title, $this->msg, $this->params );
 344                 $wgOut->output();
 345         }
 346 }
 347
 348 /**
 349  * Show an error page on a badtitle.
 350  * Similar to ErrorPage, but emit a 400 HTTP error code to let mobile
 351  * browser it is not really a valid content.
 352  *
 353  * @since 1.19
 354  * @ingroup Exception
 355  */
 356 class BadTitleError extends ErrorPageError {
 357         /**
 358          * @param string|Message $msg A message key (default: 'badtitletext')
 359          * @param array $params parameter to wfMessage()
 360          */
 361         function __construct( $msg = 'badtitletext', $params = null ) {
 362                 parent::__construct( 'badtitle', $msg, $params );
 363         }
 364
 365         /**
 366          * Just like ErrorPageError::report() but additionally set
 367          * a 400 HTTP status code (bug 33646).
 368          */
 369         function report() {
 370                 global $wgOut;
 371
 372                 // bug 33646: a badtitle error page need to return an error code
 373                 // to let mobile browser now that it is not a normal page.
 374                 $wgOut->setStatusCode( 400 );
 375                 parent::report();
 376         }
 377
 378 }
 379
 380 /**
 381  * Show an error when a user tries to do something they do not have the necessary
 382  * permissions for.
 383  *
 384  * @since 1.18
 385  * @ingroup Exception
 386  */
 387 class PermissionsError extends ErrorPageError {
 388         public $permission, $errors;
 389
 390         function __construct( $permission, $errors = array() ) {
 391                 global $wgLang;
 392
 393                 $this->permission = $permission;
 394
 395                 if ( !count( $errors ) ) {
 396                         $groups = array_map(
 397                                 array( 'User', 'makeGroupLinkWiki' ),
 398                                 User::getGroupsWithPermission( $this->permission )
 399                         );
 400
 401                         if ( $groups ) {
 402                                 $errors[] = array( 'badaccess-groups', $wgLang->commaList( $groups ), count( $groups ) );
 403                         } else {
 404                                 $errors[] = array( 'badaccess-group0' );
 405                         }
 406                 }
 407
 408                 $this->errors = $errors;
 409         }
 410
 411         function report() {
 412                 global $wgOut;
 413
 414                 $wgOut->showPermissionsErrorPage( $this->errors, $this->permission );
 415                 $wgOut->output();
 416         }
 417 }
 418
 419 /**
 420  * Show an error when the wiki is locked/read-only and the user tries to do
 421  * something that requires write access.
 422  *
 423  * @since 1.18
 424  * @ingroup Exception
 425  */
 426 class ReadOnlyError extends ErrorPageError {
 427         public function __construct() {
 428                 parent::__construct(
 429                         'readonly',
 430                         'readonlytext',
 431                         wfReadOnlyReason()
 432                 );
 433         }
 434 }
 435
 436 /**
 437  * Show an error when the user hits a rate limit.
 438  *
 439  * @since 1.18
 440  * @ingroup Exception
 441  */
 442 class ThrottledError extends ErrorPageError {
 443         public function __construct() {
 444                 parent::__construct(
 445                         'actionthrottled',
 446                         'actionthrottledtext'
 447                 );
 448         }
 449
 450         public function report() {
 451                 global $wgOut;
 452                 $wgOut->setStatusCode( 503 );
 453                 parent::report();
 454         }
 455 }
 456
 457 /**
 458  * Show an error when the user tries to do something whilst blocked.
 459  *
 460  * @since 1.18
 461  * @ingroup Exception
 462  */
 463 class UserBlockedError extends ErrorPageError {
 464         public function __construct( Block $block ) {
 465                 // @todo FIXME: Implement a more proper way to get context here.
 466                 $params = $block->getPermissionsError( RequestContext::getMain() );
 467                 parent::__construct( 'blockedtitle', array_shift( $params ), $params );
 468         }
 469 }
 470
 471 /**
 472  * Shows a generic "user is not logged in" error page.
 473  *
 474  * This is essentially an ErrorPageError exception which by default uses the
 475  * 'exception-nologin' as a title and 'exception-nologin-text' for the message.
 476  * @see bug 37627
 477  * @since 1.20
 478  *
 479  * @par Example:
 480  * @code
 481  * if( $user->isAnon() ) {
 482  *      throw new UserNotLoggedIn();
 483  * }
 484  * @endcode
 485  *
 486  * Note the parameter order differs from ErrorPageError, this allows you to
 487  * simply specify a reason without overriding the default title.
 488  *
 489  * @par Example:
 490  * @code
 491  * if( $user->isAnon() ) {
 492  *      throw new UserNotLoggedIn( 'action-require-loggedin' );
 493  * }
 494  * @endcode
 495  *
 496  * @ingroup Exception
 497  */
 498 class UserNotLoggedIn extends ErrorPageError {
 499
 500         /**
 501          * @param string $reasonMsg A message key containing the reason for the error.
 502          *        Optional, default: 'exception-nologin-text'
 503          * @param string $titleMsg A message key to set the page title.
 504          *        Optional, default: 'exception-nologin'
 505          * @param array $params Parameters to wfMessage().
 506          *        Optional, default: null
 507          */
 508         public function __construct(
 509                 $reasonMsg = 'exception-nologin-text',
 510                 $titleMsg = 'exception-nologin',
 511                 $params = null
 512         ) {
 513                 parent::__construct( $titleMsg, $reasonMsg, $params );
 514         }
 515 }
 516
 517 /**
 518  * Show an error that looks like an HTTP server error.
 519  * Replacement for wfHttpError().
 520  *
 521  * @since 1.19
 522  * @ingroup Exception
 523  */
 524 class HttpError extends MWException {
 525         private $httpCode, $header, $content;
 526
 527         /**
 528          * Constructor
 529          *
 530          * @param $httpCode Integer: HTTP status code to send to the client
 531          * @param string|Message $content content of the message
 532          * @param string|Message $header content of the header (\<title\> and \<h1\>)
 533          */
 534         public function __construct( $httpCode, $content, $header = null ) {
 535                 parent::__construct( $content );
 536                 $this->httpCode = (int)$httpCode;
 537                 $this->header = $header;
 538                 $this->content = $content;
 539         }
 540
 541         /**
 542          * Returns the HTTP status code supplied to the constructor.
 543          *
 544          * @return int
 545          */
 546         public function getStatusCode() {
 547                 return $this->httpCode;
 548         }
 549
 550         /**
 551          * Report the HTTP error.
 552          * Sends the appropriate HTTP status code and outputs an
 553          * HTML page with an error message.
 554          */
 555         public function report() {
 556                 $httpMessage = HttpStatus::getMessage( $this->httpCode );
 557
 558                 header( "Status: {$this->httpCode} {$httpMessage}", true, $this->httpCode );
 559                 header( 'Content-type: text/html; charset=utf-8' );
 560
 561                 print $this->getHTML();
 562         }
 563
 564         /**
 565          * Returns HTML for reporting the HTTP error.
 566          * This will be a minimal but complete HTML document.
 567          *
 568          * @return string HTML
 569          */
 570         public function getHTML() {
 571                 if ( $this->header === null ) {
 572                         $header = HttpStatus::getMessage( $this->httpCode );
 573                 } elseif ( $this->header instanceof Message ) {
 574                         $header = $this->header->escaped();
 575                 } else {
 576                         $header = htmlspecialchars( $this->header );
 577                 }
 578
 579                 if ( $this->content instanceof Message ) {
 580                         $content = $this->content->escaped();
 581                 } else {
 582                         $content = htmlspecialchars( $this->content );
 583                 }
 584
 585                 return "<!DOCTYPE html>\n" .
 586                         "<html><head><title>$header</title></head>\n" .
 587                         "<body><h1>$header</h1><p>$content</p></body></html>\n";
 588         }
 589 }
 590
 591 /**
 592  * Handler class for MWExceptions
 593  * @ingroup Exception
 594  */
 595 class MWExceptionHandler {
 596         /**
 597          * Install an exception handler for MediaWiki exception types.
 598          */
 599         public static function installHandler() {
 600                 set_exception_handler( array( 'MWExceptionHandler', 'handle' ) );
 601         }
 602
 603         /**
 604          * Report an exception to the user
 605          */
 606         protected static function report( Exception $e ) {
 607                 global $wgShowExceptionDetails;
 608
 609                 $cmdLine = MWException::isCommandLine();
 610
 611                 if ( $e instanceof MWException ) {
 612                         try {
 613                                 // Try and show the exception prettily, with the normal skin infrastructure
 614                                 $e->report();
 615                         } catch ( Exception $e2 ) {
 616                                 // Exception occurred from within exception handler
 617                                 // Show a simpler error message for the original exception,
 618                                 // don't try to invoke report()
 619                                 $message = "MediaWiki internal error.\n\n";
 620
 621                                 if ( $wgShowExceptionDetails ) {
 622                                         $message .= 'Original exception: ' . self::formatRedactedTrace( $e ) . "\n\n" .
 623                                                 'Exception caught inside exception handler: ' . $e2->__toString();
 624                                 } else {
 625                                         $message .= "Exception caught inside exception handler.\n\n" .
 626                                                 "Set \$wgShowExceptionDetails = true; at the bottom of LocalSettings.php " .
 627                                                 "to show detailed debugging information.";
 628                                 }
 629
 630                                 $message .= "\n";
 631
 632                                 if ( $cmdLine ) {
 633                                         self::printError( $message );
 634                                 } else {
 635                                         echo nl2br( htmlspecialchars( $message ) ) . "\n";
 636                                 }
 637                         }
 638                 } else {
 639                         $message = "Unexpected non-MediaWiki exception encountered, of type \"" .
 640                                 get_class( $e ) . "\"";
 641
 642                         if ( $wgShowExceptionDetails ) {
 643                                 $message .= "\nexception '" . get_class( $e ) . "' in " .
 644                                         $e->getFile() . ":" . $e->getLine() . "\nStack trace:\n" .
 645                                         self::formatRedactedTrace( $e ) . "\n";
 646                         }
 647
 648                         if ( $cmdLine ) {
 649                                 self::printError( $message );
 650                         } else {
 651                                 echo nl2br( htmlspecialchars( $message ) ) . "\n";
 652                         }
 653                 }
 654         }
 655
 656         /**
 657          * Print a message, if possible to STDERR.
 658          * Use this in command line mode only (see isCommandLine)
 659          *
 660          * @param string $message Failure text
 661          */
 662         public static function printError( $message ) {
 663                 # NOTE: STDERR may not be available, especially if php-cgi is used from the
 664                 # command line (bug #15602). Try to produce meaningful output anyway. Using
 665                 # echo may corrupt output to STDOUT though.
 666                 if ( defined( 'STDERR' ) ) {
 667                         fwrite( STDERR, $message );
 668                 } else {
 669                         echo $message;
 670                 }
 671         }
 672
 673         /**
 674          * Exception handler which simulates the appropriate catch() handling:
 675          *
 676          *   try {
 677          *       ...
 678          *   } catch ( MWException $e ) {
 679          *       $e->report();
 680          *   } catch ( Exception $e ) {
 681          *       echo $e->__toString();
 682          *   }
 683          */
 684         public static function handle( $e ) {
 685                 global $wgFullyInitialised;
 686
 687                 self::report( $e );
 688
 689                 // Final cleanup
 690                 if ( $wgFullyInitialised ) {
 691                         try {
 692                                 // uses $wgRequest, hence the $wgFullyInitialised condition
 693                                 wfLogProfilingData();
 694                         } catch ( Exception $e ) {
 695                         }
 696                 }
 697
 698                 // Exit value should be nonzero for the benefit of shell jobs
 699                 exit( 1 );
 700         }
 701
 702         /**
 703          * Get the stack trace from the exception as a string, redacting certain
 704          * function arguments in the process.
 705          * @param Exception $e The exception
 706          * @return string The stack trace as a string
 707          */
 708         public static function formatRedactedTrace( Exception $e ) {
 709                 global $wgRedactedFunctionArguments;
 710                 $finalExceptionText = '';
 711
 712                 // Unique value to indicate redacted parameters
 713                 $redacted = new stdClass();
 714
 715                 foreach ( $e->getTrace() as $i => $call ) {
 716                         $checkFor = array();
 717                         if ( isset( $call['class'] ) ) {
 718                                 $checkFor[] = $call['class'] . '::' . $call['function'];
 719                                 foreach ( class_parents( $call['class'] ) as $parent ) {
 720                                         $checkFor[] = $parent . '::' . $call['function'];
 721                                 }
 722                         } else {
 723                                 $checkFor[] = $call['function'];
 724                         }
 725
 726                         foreach ( $checkFor as $check ) {
 727                                 if ( isset( $wgRedactedFunctionArguments[$check] ) ) {
 728                                         foreach ( (array)$wgRedactedFunctionArguments[$check] as $argNo ) {
 729                                                 $call['args'][$argNo] = $redacted;
 730                                         }
 731                                 }
 732                         }
 733
 734                         if ( isset( $call['file'] ) && isset( $call['line'] ) ) {
 735                                 $finalExceptionText .= "#{$i} {$call['file']}({$call['line']}): ";
 736                         } else {
 737                                 // 'file' and 'line' are unset for calls via call_user_func (bug 55634)
 738                                 // This matches behaviour of Exception::getTraceAsString to instead
 739                                 // display "[internal function]".
 740                                 $finalExceptionText .= "#{$i} [internal function]: ";
 741                         }
 742
 743                         if ( isset( $call['class'] ) ) {
 744                                 $finalExceptionText .= $call['class'] . $call['type'] . $call['function'];
 745                         } else {
 746                                 $finalExceptionText .= $call['function'];
 747                         }
 748                         $args = array();
 749                         if ( isset( $call['args'] ) ) {
 750                                 foreach ( $call['args'] as $arg ) {
 751                                         if ( $arg === $redacted ) {
 752                                                 $args[] = 'REDACTED';
 753                                         } elseif ( is_object( $arg ) ) {
 754                                                 $args[] = 'Object(' . get_class( $arg ) . ')';
 755                                         } elseif( is_array( $arg ) ) {
 756                                                 $args[] = 'Array';
 757                                         } else {
 758                                                 $args[] = var_export( $arg, true );
 759                                         }
 760                                 }
 761                         }
 762                         $finalExceptionText .= '(' . implode( ', ', $args ) . ")\n";
 763                 }
 764                 return $finalExceptionText . '#' . ( $i + 1 ) . ' {main}';
 765         }
 766
 767         /**
 768          * Get the ID for this error.
 769          *
 770          * The ID is saved so that one can match the one output to the user (when
 771          * $wgShowExceptionDetails is set to false), to the entry in the debug log.
 772          *
 773          * @since 1.22
 774          * @param Exception $e
 775          * @return string
 776          */
 777         public static function getLogId( Exception $e ) {
 778                 if ( !isset( $e->_mwLogId ) ) {
 779                         $e->_mwLogId = wfRandomString( 8 );
 780                 }
 781                 return $e->_mwLogId;
 782         }
 783
 784         /**
 785          * Return the requested URL and point to file and line number from which the
 786          * exception occurred.
 787          *
 788          * @since 1.22
 789          * @param Exception $e
 790          * @return string
 791          */
 792         public static function getLogMessage( Exception $e ) {
 793                 global $wgRequest;
 794
 795                 $id = self::getLogId( $e );
 796                 $file = $e->getFile();
 797                 $line = $e->getLine();
 798                 $message = $e->getMessage();
 799
 800                 if ( isset( $wgRequest ) && !$wgRequest instanceof FauxRequest ) {
 801                         $url = $wgRequest->getRequestURL();
 802                         if ( !$url ) {
 803                                 $url = '[no URL]';
 804                         }
 805                 } else {
 806                         $url = '[no req]';
 807                 }
 808
 809                 return "[$id] $url   Exception from line $line of $file: $message";
 810         }
 811
 812         /**
 813          * Log an exception to the exception log (if enabled).
 814          *
 815          * This method must not assume the exception is an MWException,
 816          * it is also used to handle PHP errors or errors from other libraries.
 817          *
 818          * @since 1.22
 819          * @param Exception $e
 820          */
 821         public static function logException( Exception $e ) {
 822                 global $wgLogExceptionBacktrace;
 823
 824                 if ( !( $e instanceof MWException ) || $e->isLoggable() ) {
 825                         $log = self::getLogMessage( $e );
 826                         if ( $wgLogExceptionBacktrace ) {
 827                                 wfDebugLog( 'exception', $log . "\n" . self::formatRedactedTrace( $e ) . "\n" );
 828                         } else {
 829                                 wfDebugLog( 'exception', $log );
 830                         }
 831                 }
 832         }
 833
 834 }