How to install php7 modules in archlinux?

Question

I have the following php version installed:

PHP 7.0.2 (cli) (built: Jan  6 2016 11:50:59) ( NTS )
Copyright (c) 1997-2015 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2015 Zend Technologies

Any php command on command line interface brings up the following error:

PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib/php/modules/openssl.so' - /usr/lib/php/modules/openssl.so: cannot open shared object file: No such file or directory in Unknown on line 0
PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib/php/modules/posix.so' - /usr/lib/php/modules/posix.so: cannot open shared object file: No such file or directory in Unknown on line 0
PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib/php/modules/xcache.so' - /usr/lib/php/modules/xcache.so: undefined symbol: zval_used_for_init in Unknown on line 0

I have the modules enabled in /etc/php/php.ini:

extension=openssl.so
[...]
extension=posix.so

xcache is enabled the same way in /etc/php/conf.d/xcache.ini:

extension=xcache.so
xcache.size=64M
xcache.var_size=64M

This is the content of /usr/lib/php/modules:

cu.so bz2.so curl.so exif.so gd.so gmp.so intl.so mcrypt.so opcache.so
pdo_pgsql.so shmop.so sockets.so sysvsem.so xcache.so zip.so bcmath.so 
calendar.so dba.so ftp.so gettext.so iconv.so ldap.so mysqli.so pdo_mysql.so
pgsql.so soap.so sysvmsg.so sysvshm.so xmlrpc.so

I wonder, why are the modules missing and how to reinstall them? I can't find any modules in the pacman modules. The archlinux wikis also only refers to uncommenting the extensions in php.ini.

I'm running ArchLinux kernel version 4.0.6-1-ARCH x86_64 GNU/Linux.

Answer 1

Ok, here it is answered by pierre schmitz, thx nymous for the link:

openssl, phar and posix modules are now built in php7 core. Remove the corresponding directives from your php.ini, e.g. ;extension=openssl.so.

php-xcache is incompatible with php7, remove package, the project seems dead.

full list of 3rd party package status:

| Package          | Status       | Solution                                                     |
|------------------|--------------|--------------------------------------------------------------|
| graphviz         | incompatible | remove PHP bindings                                          |
| php-apcu         | compatible   | update to version 5                                          |
| php-geoip        | incompatible | remove package                                               |
| php-memcache     | incompatible | remove package, project seems dead                           |
| php-memcached    | incompatible | remove package, move back when upstream version is available |
| php-mongo        | incompatible | remove package, superseded by the mongodb driver             |
| php-xcache       | incompatible | remove package, project seems dead                           |
| uwsgi-plugin-php | incompatible | remove PHP support, upstream update seems possible           |
| xdebug           | compatible   | update to latest release candidate of version 2.4            |

Answer 2

php no longer has support for that stuff in modules.
Look at this article https://pierre-schmitz.com/php-7-on-arch-linux/