Ticket #36926: autoload-compat.php

<?php

if ( ! isset( $spl_autoloaders ) ) {
        $spl_autoloaders = array();
}

/**
 * Autoloader compatibility callback.
 *
 * @param string $classname Class to attempt autoloading.
 */
function __autoload( $classname ) {
        global $spl_autoloaders;
        foreach ( $spl_autoloaders as $autoloader ) {
                call_user_func( $autoloader, $classname );

                // If it has been autoloaded, stop processing.
                if ( class_exists( $classname, false ) ) {
                        return;
                }
        }
}

/**
 * Register a function to be autoloaded.
 *
 * @param callable $autoload_function The function to register.
 * @param boolean $throw Should the function throw an exception if the function isn't callable?
 * @param boolean $prepend Should we prepend the function to the stack?
 */
function spl_autoload_register( $autoload_function, $throw = true, $prepend = false ) {
        if ( $throw && ! is_callable( $autoload_function ) ) {
                // String not translated to match PHP core.
                throw new Exception( 'Function not callable' );
        }

        global $spl_autoloaders;

        // Don't allow multiple registration.
        if ( in_array( $autoload_function, $spl_autoloaders ) ) {
                return;
        }

        if ( $prepend ) {
                array_unshift( $spl_autoloaders, $autoload_function );
        } else {
                $spl_autoloaders[] = $autoload_function;
        }
}

/**
 * Unregister an autoloader function.
 *
 * @param callable $function The function to unregister.
 * @return boolean True if the function was unregistered, false if it could not be.
 */
function spl_autoload_unregister( $function ) {
        global $spl_autoloaders;
        foreach ( $spl_autoloaders as &$autoloader ) {
                if ( $autoloader === $function ) {
                        unset( $autoloader );
                        return true;
                }
        }

        return false;
}

/**
 * Get the registered autoloader functions.
 *
 * @return array List of autoloader functions.
 */
function spl_autoload_functions() {
        return $GLOBALS['spl_autoloaders'];
}