bootstrap.inc

<?php


/**
 * @file
 * Functions that need to be loaded on every Drupal request.
 */
use Drupal\Component\Utility\Crypt;
use Drupal\Core\Test\TestDatabase;
use Drupal\Core\Utility\Error;
use Drupal\Core\StringTranslation\TranslatableMarkup;
// cspell:ignore htkey

/**
 * Error reporting level: display no errors.
 */
const ERROR_REPORTING_HIDE = 'hide';

/**
 * Error reporting level: display errors and warnings.
 */
const ERROR_REPORTING_DISPLAY_SOME = 'some';

/**
 * Error reporting level: display all messages.
 */
const ERROR_REPORTING_DISPLAY_ALL = 'all';

/**
 * Error reporting level: display all messages, plus backtrace information.
 */
const ERROR_REPORTING_DISPLAY_VERBOSE = 'verbose';

/**
 * The maximum number of characters in a module or theme name.
 */
const DRUPAL_EXTENSION_NAME_MAX_LENGTH = 50;

/**
 * Defines the root directory of the Drupal installation.
 *
 * This strips two levels of directories off the current directory.
 */
define('DRUPAL_ROOT', dirname(__DIR__, 2));

/**
 * Keep backward compatibility for sites with references to TranslationWrapper.
 */
class_alias(TranslatableMarkup::class, '\\Drupal\\Core\\StringTranslation\\TranslationWrapper', TRUE);

/**
 * Translates a string to the current language or to a given language.
 *
 * In order for strings to be localized, make them available in one of the ways
 * supported by the @link i18n Localization API. @endlink When possible, use
 * the \Drupal\Core\StringTranslation\StringTranslationTrait $this->t().
 * Otherwise create a new \Drupal\Core\StringTranslation\TranslatableMarkup
 * object directly.
 *
 * See \Drupal\Core\StringTranslation\TranslatableMarkup::__construct() for
 * important security information and usage guidelines.
 *
 * @param string $string
 *   A string containing the English text to translate.
 * @param array $args
 *   (optional) An associative array of replacements to make after translation.
 *   Based on the first character of the key, the value is escaped and/or
 *   themed. See
 *   \Drupal\Component\Render\FormattableMarkup::placeholderFormat() for
 *   details.
 * @param array $options
 *   (optional) An associative array of additional options, with the following
 *   elements:
 *   - 'langcode' (defaults to the current language): A language code, to
 *     translate to a language other than what is used to display the page.
 *   - 'context' (defaults to the empty context): The context the source string
 *     belongs to. See the @link i18n Internationalization topic @endlink for
 *     more information about string contexts.
 *
 * @return \Drupal\Core\StringTranslation\TranslatableMarkup
 *   An object that, when cast to a string, returns the translated string.
 *
 * @see \Drupal\Component\Render\FormattableMarkup::placeholderFormat()
 * @see \Drupal\Core\StringTranslation\StringTranslationTrait::t()
 * @see \Drupal\Core\StringTranslation\TranslatableMarkup::__construct()
 *
 * @ingroup sanitization
 */
function t($string, array $args = [], array $options = []) {
    return new TranslatableMarkup($string, $args, $options);
}

/**
 * Provides custom PHP error handling.
 *
 * @param $error_level
 *   The level of the error raised.
 * @param $message
 *   The error message.
 * @param $filename
 *   (optional) The filename that the error was raised in.
 * @param $line
 *   (optional) The line number the error was raised at.
 */
function _drupal_error_handler($error_level, $message, $filename = NULL, $line = NULL) {
    require_once __DIR__ . '/errors.inc';
    _drupal_error_handler_real($error_level, $message, $filename, $line);
}

/**
 * Provides custom PHP exception handling.
 *
 * Uncaught exceptions are those not enclosed in a try/catch block. They are
 * always fatal: the execution of the script will stop as soon as the exception
 * handler exits.
 *
 * @param \Exception|\Throwable $exception
 *   The exception object that was thrown.
 */
function _drupal_exception_handler($exception) {
    require_once __DIR__ . '/errors.inc';
    try {
        // Log the message to the watchdog and return an error page to the user.
        _drupal_log_error(Error::decodeException($exception), TRUE);
    } catch (\Throwable $error) {
        _drupal_exception_handler_additional($exception, $error);
    }
}

/**
 * Displays any additional errors caught while handling an exception.
 *
 * @param \Exception|\Throwable $exception
 *   The first exception object that was thrown.
 * @param \Exception|\Throwable $exception2
 *   The second exception object that was thrown.
 */
function _drupal_exception_handler_additional($exception, $exception2) {
    // Another uncaught exception was thrown while handling the first one.
    // If we are displaying errors, then do so with no possibility of a further
    // uncaught exception being thrown.
    if (error_displayable()) {
        print '<h1>Additional uncaught exception thrown while handling exception.</h1>';
        print '<h2>Original</h2><p>' . Error::renderExceptionSafe($exception) . '</p>';
        print '<h2>Additional</h2><p>' . Error::renderExceptionSafe($exception2) . '</p><hr />';
    }
}

/**
 * Returns the test prefix if this is an internal request from a test.
 *
 * @param string $new_prefix
 *   Internal use only. A new prefix to be stored.
 *
 * @return string|false
 *   Either the simpletest prefix (the string "simpletest" followed by any
 *   number of digits) or FALSE if the user agent does not contain a valid
 *   HMAC and timestamp.
 */
function drupal_valid_test_ua($new_prefix = NULL) {
    static $test_prefix;
    if (isset($new_prefix)) {
        $test_prefix = $new_prefix;
    }
    if (isset($test_prefix)) {
        return $test_prefix;
    }
    // Unless the below User-Agent and HMAC validation succeeds, we are not in
    // a test environment.
    $test_prefix = FALSE;
    // A valid test request will contain a hashed and salted authentication code.
    // Check if this code is present in a cookie or custom user agent string.
    $http_user_agent = $_SERVER['HTTP_USER_AGENT'] ?? NULL;
    $user_agent = $_COOKIE['SIMPLETEST_USER_AGENT'] ?? $http_user_agent;
    if (isset($user_agent) && preg_match("/^simple(\\w+\\d+):(.+):(.+):(.+)\$/", $user_agent, $matches)) {
        [
            ,
            $prefix,
            $time,
            $salt,
            $hmac,
        ] = $matches;
        $check_string = $prefix . ':' . $time . ':' . $salt;
        // Read the hash salt prepared by drupal_generate_test_ua().
        // This function is called before settings.php is read and Drupal's error
        // handlers are set up. While Drupal's error handling may be properly
        // configured on production sites, the server's PHP error_reporting may not.
        // Ensure that no information leaks on production sites.
        $test_db = new TestDatabase($prefix);
        $key_file = DRUPAL_ROOT . '/' . $test_db->getTestSitePath() . '/.htkey';
        if (!is_readable($key_file) || is_dir($key_file)) {
            header($_SERVER['SERVER_PROTOCOL'] . ' 403 Forbidden');
            exit;
        }
        $private_key = file_get_contents($key_file);
        // The string from drupal_generate_test_ua() is 74 bytes long. If we don't
        // have it, tests cannot be allowed.
        if (empty($private_key) || strlen($private_key) < 74) {
            header($_SERVER['SERVER_PROTOCOL'] . ' 403 Forbidden');
            exit;
        }
        // The file properties add more entropy not easily accessible to others.
        $key = $private_key . filectime(__FILE__) . fileinode(__FILE__);
        $time_diff = time() - $time;
        $test_hmac = Crypt::hmacBase64($check_string, $key);
        // Since we are making a local request a 600 second time window is allowed,
        // and the HMAC must match.
        if ($time_diff >= 0 && $time_diff <= 600 && hash_equals($test_hmac, $hmac)) {
            $test_prefix = $prefix;
        }
        else {
            header($_SERVER['SERVER_PROTOCOL'] . ' 403 Forbidden (SIMPLETEST_USER_AGENT invalid)');
            exit;
        }
    }
    return $test_prefix;
}

/**
 * Generates a user agent string with a HMAC and timestamp for tests.
 *
 * @return string|null
 *   The user agent, or NULL on failure.
 */
function drupal_generate_test_ua($prefix) {
    static $key, $last_prefix;
    if (!isset($key) || $last_prefix != $prefix) {
        $last_prefix = $prefix;
        $test_db = new TestDatabase($prefix);
        $key_file = DRUPAL_ROOT . '/' . $test_db->getTestSitePath() . '/.htkey';
        // When issuing an outbound HTTP client request from within an inbound test
        // request, then the outbound request has to use the same User-Agent header
        // as the inbound request. A newly generated private key for the same test
        // prefix would invalidate all subsequent inbound requests.
        // @see \Drupal\Core\Test\HttpClientMiddleware\TestHttpClientMiddleware
        if (DRUPAL_TEST_IN_CHILD_SITE && ($parent_prefix = drupal_valid_test_ua())) {
            if ($parent_prefix != $prefix) {
                throw new \RuntimeException("Malformed User-Agent: Expected '{$parent_prefix}' but got '{$prefix}'.");
            }
            // If the file is not readable, a PHP warning is expected in this case.
            $private_key = file_get_contents($key_file);
        }
        else {
            // Generate and save a new hash salt for a test run.
            // Consumed by drupal_valid_test_ua() before settings.php is loaded.
            $private_key = Crypt::randomBytesBase64(55);
            if (!@file_put_contents($key_file, $private_key)) {
                return NULL;
            }
        }
        // The file properties add more entropy not easily accessible to others.
        $key = $private_key . filectime(__FILE__) . fileinode(__FILE__);
    }
    // Generate a moderately secure HMAC based on the database credentials.
    $salt = uniqid('', TRUE);
    $check_string = $prefix . ':' . time() . ':' . $salt;
    return 'simple' . $check_string . ':' . Crypt::hmacBase64($check_string, $key);
}

/**
 * Enables use of the theme system without requiring database access.
 *
 * Loads and initializes the theme system for site installs, updates and when
 * the site is in maintenance mode. This also applies when the database fails.
 *
 * @see _drupal_maintenance_theme()
 */
function drupal_maintenance_theme() {
    require_once __DIR__ . '/theme.maintenance.inc';
    _drupal_maintenance_theme();
}

/**
 * Provides central static variable storage.
 *
 * All functions requiring a static variable to persist or cache data within
 * a single page request are encouraged to use this function unless it is
 * absolutely certain that the static variable will not need to be reset during
 * the page request. By centralizing static variable storage through this
 * function, other functions can rely on a consistent API for resetting any
 * other function's static variables.
 *
 * Example:
 * @code
 * function example_list($field = 'default') {
 *   $examples = &drupal_static(__FUNCTION__);
 *   if (!isset($examples)) {
 *     // If this function is being called for the first time after a reset,
 *     // query the database and execute any other code needed to retrieve
 *     // information.
 *     ...
 *   }
 *   if (!isset($examples[$field])) {
 *     // If this function is being called for the first time for a particular
 *     // index field, then execute code needed to index the information already
 *     // available in $examples by the desired field.
 *     ...
 *   }
 *   // Subsequent invocations of this function for a particular index field
 *   // skip the above two code blocks and quickly return the already indexed
 *   // information.
 *   return $examples[$field];
 * }
 * function examples_admin_overview() {
 *   // When building the content for the overview page, make sure to get
 *   // completely fresh information.
 *   drupal_static_reset('example_list');
 *   ...
 * }
 * @endcode
 *
 * In a few cases, a function can have certainty that there is no legitimate
 * use-case for resetting that function's static variable. This is rare,
 * because when writing a function, it's hard to forecast all the situations in
 * which it will be used. A guideline is that if a function's static variable
 * does not depend on any information outside of the function that might change
 * during a single page request, then it's ok to use the "static" keyword
 * instead of the drupal_static() function.
 *
 * Example:
 * @code
 * function my_module_log_stream_handle($new_handle = NULL) {
 *   static $handle;
 *   if (isset($new_handle)) {
 *     $handle = $new_handle;
 *   }
 *   return $handle;
 * }
 * @endcode
 *
 * In a few cases, a function needs a resettable static variable, but the
 * function is called many times (100+) during a single page request, so
 * every microsecond of execution time that can be removed from the function
 * counts. These functions can use a more cumbersome, but faster variant of
 * calling drupal_static(). It works by storing the reference returned by
 * drupal_static() in the calling function's own static variable, thereby
 * removing the need to call drupal_static() for each iteration of the function.
 * Conceptually, it replaces:
 * @code
 * $foo = &drupal_static(__FUNCTION__);
 * @endcode
 * with:
 * @code
 * // Unfortunately, this does not work.
 * static $foo = &drupal_static(__FUNCTION__);
 * @endcode
 * However, the above line of code does not work, because PHP only allows static
 * variables to be initialized by literal values, and does not allow static
 * variables to be assigned to references.
 * - http://php.net/manual/language.variables.scope.php#language.variables.scope.static
 * - http://php.net/manual/language.variables.scope.php#language.variables.scope.references
 * The example below shows the syntax needed to work around both limitations.
 * For benchmarks and more information, see https://www.drupal.org/node/619666.
 *
 * Example:
 * @code
 * function example_default_format_type() {
 *   // Use the advanced drupal_static() pattern, since this is called very often.
 *   static $drupal_static_fast;
 *   if (!isset($drupal_static_fast)) {
 *     $drupal_static_fast['format_type'] = &drupal_static(__FUNCTION__);
 *   }
 *   $format_type = &$drupal_static_fast['format_type'];
 *   ...
 * }
 * @endcode
 *
 * @param $name
 *   Globally unique name for the variable. For a function with only one static,
 *   variable, the function name (e.g. via the PHP magic __FUNCTION__ constant)
 *   is recommended. For a function with multiple static variables add a
 *   distinguishing suffix to the function name for each one.
 * @param $default_value
 *   Optional default value.
 * @param $reset
 *   TRUE to reset one or all variables(s). This parameter is only used
 *   internally and should not be passed in; use drupal_static_reset() instead.
 *   (This function's return value should not be used when TRUE is passed in.)
 *
 * @return mixed
 *   Returns a variable by reference.
 *
 * @see drupal_static_reset()
 */
function &drupal_static($name, $default_value = NULL, $reset = FALSE) {
    static $data = [], $defaults = [];
    if (isset($name)) {
        // Check if we're dealing with a previously defined static variable.
        if (\array_key_exists($name, $data)) {
            // Both $data[$name] and (implicitly) $defaults[$name] statics exist.
            if ($reset) {
                // Reset pre-existing static variable to its default value.
                $data[$name] = $defaults[$name];
            }
        }
        else {
            // Neither $data[$name] nor $defaults[$name] static variables exist.
            if ($reset) {
                // Reset was called before any value for $name was set, so we should
                // not set anything ($default_value is not reliable in this case). As
                // the function returns a reference, we must still return a variable.
                // (Code using $reset does not use the return value).
                return $data;
            }
            // First call with new non-NULL $name. Initialize a new static variable.
            $defaults[$name] = $data[$name] = $default_value;
        }
        // Return a reference to the named variable.
        return $data[$name];
    }
    else {
        // Reset all: ($name == NULL). This needs to be done one at a time so that
        // references returned by earlier invocations of drupal_static() also get
        // reset.
        foreach ($defaults as $name => $value) {
            $data[$name] = $value;
        }
        // As the function returns a reference, we must still return a variable.
        return $data;
    }
}

/**
 * Resets one or all centrally stored static variable(s).
 *
 * @param $name
 *   Name of the static variable to reset. Omit to reset all variables.
 *   Resetting all variables should only be used, for example, for running
 *   unit tests with a clean environment.
 */
function drupal_static_reset($name = NULL) {
    drupal_static($name, NULL, TRUE);
}

/**
 * Registers a function for execution on shutdown.
 *
 * Wrapper for register_shutdown_function() that catches thrown exceptions to
 * avoid "Exception thrown without a stack frame in Unknown".
 *
 * @param callable $callback
 *   The shutdown function to register.
 * @param ...
 *   Additional arguments to pass to the shutdown function.
 *
 * @return array
 *   Array of shutdown functions to be executed.
 *
 * @see register_shutdown_function()
 * @ingroup php_wrappers
 */
function &drupal_register_shutdown_function($callback = NULL) {
    // We cannot use drupal_static() here because the static cache is reset during
    // batch processing, which breaks batch handling.
    static $callbacks = [];
    if (isset($callback)) {
        // Only register the internal shutdown function once.
        if (empty($callbacks)) {
            register_shutdown_function('_drupal_shutdown_function');
        }
        $args = func_get_args();
        // Remove $callback from the arguments.
        unset($args[0]);
        // Save callback and arguments
        $callbacks[] = [
            'callback' => $callback,
            'arguments' => $args,
        ];
    }
    return $callbacks;
}

/**
 * Executes registered shutdown functions.
 */
function _drupal_shutdown_function() {
    $callbacks =& drupal_register_shutdown_function();
    // Set the CWD to DRUPAL_ROOT as it is not guaranteed to be the same as it
    // was in the normal context of execution.
    chdir(DRUPAL_ROOT);
    try {
        reset($callbacks);
        // Do not use foreach() here because it is possible that the callback will
        // add to the $callbacks array via drupal_register_shutdown_function().
        while ($callback = current($callbacks)) {
            call_user_func_array($callback['callback'], $callback['arguments']);
            next($callbacks);
        }
    } catch (\Throwable $error) {
        _drupal_shutdown_function_handle_exception($error);
    }
}

/**
 * Displays and logs any errors that may happen during shutdown.
 *
 * @param \Exception|\Throwable $exception
 *   The exception object that was thrown.
 *
 * @see _drupal_shutdown_function()
 */
function _drupal_shutdown_function_handle_exception($exception) {
    // If using PHP-FPM then fastcgi_finish_request() will have been fired
    // preventing further output to the browser.
    if (!function_exists('fastcgi_finish_request')) {
        // If we are displaying errors, then do so with no possibility of a
        // further uncaught exception being thrown.
        require_once __DIR__ . '/errors.inc';
        if (error_displayable()) {
            print '<h1>Uncaught exception thrown in shutdown function.</h1>';
            print '<p>' . Error::renderExceptionSafe($exception) . '</p><hr />';
        }
    }
    error_log($exception);
}