Debug/Debug.php
public static function enable($errorReportingLevel = null, $displayErrors = true)
    {
        if (static::$enabled) {
            return;
        }

        static::$enabled = true;

        if (null !== $errorReportingLevel) {
            error_reporting($errorReportingLevel);
        } else {
            error_reporting(-1);
        }

        if ('cli' !== PHP_SAPI) {
            ini_set('display_errors', 0);
            ExceptionHandler::register();
        } elseif ($displayErrors && (!ini_get('log_errors') || ini_get('error_log'))) {
            // CLI - display errors only if they're not already logged to STDERR
            ini_set('display_errors', 1);
        }
        if ($displayErrors) {
            ErrorHandler::register(new ErrorHandler(new BufferingLogger()));
        } else {
            ErrorHandler::register()->throwAt(0, true);
        }

        DebugClassLoader::enable();
    }
public static function enable($errorReportingLevel = null, $displayErrors = true)
    {
        if (static::$enabled) {
            return;
        }

        static::$enabled = true;

        if (null !== $errorReportingLevel) {
            error_reporting($errorReportingLevel);
        } else {
            error_reporting(-1);
        }

        if ('cli' !== PHP_SAPI) {
            ini_set('display_errors', 0);
            ExceptionHandler::register();
        } elseif ($displayErrors && (!ini_get('log_errors') || ini_get('error_log'))) {
            // CLI - display errors only if they're not already logged to STDERR
            ini_set('display_errors', 1);
        }
        if ($displayErrors) {
            ErrorHandler::register(new ErrorHandler(new BufferingLogger()));
        } else {
            ErrorHandler::register()->throwAt(0, true);
        }

        DebugClassLoader::enable();
    }
public static function enable ( $ errorReportingLevel = null , $ displayErrors = true ) { if ( static :: $ enabled ) { return ; } static :: $ enabled = true ; if ( null !== $ errorReportingLevel ) { error_reporting ( $ errorReportingLevel ) ; } else { error_reporting ( - 1 ) ; } if ( 'cli' !== PHP_SAPI ) { ini_set ( 'display_errors' , 0 ) ; ExceptionHandler :: register ( ) ; } elseif ( $ displayErrors && ( ! ini_get ( 'log_errors' ) || ini_get ( 'error_log' ) ) ) { // CLI - display errors only if they're not already logged to STDERR ini_set ( 'display_errors' , 1 ) ; } if ( $ displayErrors ) { ErrorHandler :: register ( new ErrorHandler ( new BufferingLogger ( ) ) ) ; } else { ErrorHandler :: register ( ) -> throwAt ( 0 , true ) ; } DebugClassLoader :: enable ( ) ; }
Enables the debug tools.

This method registers an error handler and an exception handler.

If the Symfony ClassLoader component is available, a special
class loader is also registered.

@param int  $errorReportingLevel The level of error reporting you want
@param bool $displayErrors       Whether to display errors (for development) or just log them (for production)
Enables the debug tools .