hhvm -v "Eval.EnableZendCompat = true" get_loaded_extensions.php

get_loaded_extensions.log

Array
(
    [0] => apc
    [1] => bcmath
    [2] => bz2
    [3] => ctype
    [4] => curl
    [5] => date
    [6] => dom
    [7] => exif
    [8] => fb
    [9] => fileinfo
    [10] => filter
    [11] => gd
    [12] => hash
    [13] => hotprofiler
    [14] => iconv
    [15] => icu_ucsdet
    [16] => icu_uspoof
    [17] => idn
    [18] => imap
    [19] => intl.not-done
    [20] => json
    [21] => ldap
    [22] => mbstring
    [23] => mcrypt
    [24] => memcache
    [25] => memcached
    [26] => mysql
    [27] => openssl
    [28] => pcntl
    [29] => pcre
    [30] => PDO
    [31] => pdo_mysql
    [32] => pdo_sqlite
    [33] => phar
    [34] => posix
    [35] => Reflection
    [36] => server
    [37] => session
    [38] => SimpleXML
    [39] => soap
    [40] => sockets
    [41] => SPL
    [42] => sqlite3
    [43] => sysvmsg
    [44] => sysvsem
    [45] => sysvshm
    [46] => thread
    [47] => thrift_protocol
    [48] => tokenizer
    [49] => xhprof
    [50] => xml
    [51] => xmlreader
    [52] => xmlwriter
    [53] => zip
    [54] => zlib
)