How to restrict virtual hosting php scripts within site directory without open_basedir?

Question

PHP

The WAMP bundle is installed on the local computer . Sites are organized into folders and virtual hosts are configured. Each contains php scripts for your site. To protect against possible unwanted actions, the open_basedir directive in httpd.conf is used . However, for many CMS, for some reason, it sometimes causes “glitches”, for example, if in httpd.conf :
php_value open_basedir "S:/www/mysite.ru/"
then you may encounter such messages while working with scripts:

Warning: is_file(): open_basedir restriction in effect. File(S:/www/mysite.ru/S:/www/mysite.ru/admin/media/style/common/welcome.tpl)

IMHO: Which probably indicates that as a result of applying the - directive, the script cannot adequately obtain the root path from some system variable.
How to limit the actions of php scripts to your virtual host in another way?