select dbms_metadata.get_ddl('ROLE',role) from dba_roles ;

ECSCDAS1S > @cr8_all_existing_roles.sql

'CREATEROLE'||ROLE||';'
-------------------------------------------
create role PV_WR_ROLE;
create role LIVE_RO_ROLE;
create role LIVE_WR_ROLE;
create role LIVE_WR_ROLE2;
create role PV_RO_ROLE;
create role FEEDS_BATCH_ROLE;
create role SHARED_WR_ROLE;
create role SHARED_RO_ROLE;

8 rows selected.

ECSCDAS1S > list
  1  select 'create role '||role||';' from dba_roles
  2  where role not in (
  3  'CONNECT',
  4  'RESOURCE',
  5  'DBA',
  6  'SELECT_CATALOG_ROLE',
  7  'EXECUTE_CATALOG_ROLE',
  8  'DELETE_CATALOG_ROLE',
  9  'EXP_FULL_DATABASE',
 10  'IMP_FULL_DATABASE',
 11  'LOGSTDBY_ADMINISTRATOR',
 12  'DBFS_ROLE',
 13  'AQ_ADMINISTRATOR_ROLE',
 14  'AQ_USER_ROLE',
 15  'DATAPUMP_EXP_FULL_DATABASE',
 16  'DATAPUMP_IMP_FULL_DATABASE',
 17  'ADM_PARALLEL_EXECUTE_TASK',
 18  'GATHER_SYSTEM_STATISTICS',
 19  'JAVA_DEPLOY',
 20  'RECOVERY_CATALOG_OWNER',
 21  'SCHEDULER_ADMIN',
 22  'HS_ADMIN_SELECT_ROLE',
 23  'HS_ADMIN_EXECUTE_ROLE',
 24  'HS_ADMIN_ROLE',
 25  'GLOBAL_AQ_USER_ROLE',
 26  'OEM_ADVISOR',
 27  'OEM_MONITOR',
 28  'WM_ADMIN_ROLE',
 29  'JAVAUSERPRIV',
 30  'JAVAIDPRIV',
 31  'JAVASYSPRIV',
 32  'JAVADEBUGPRIV',
 33  'EJBCLIENT',
 34  'JMXSERVER',
 35  'JAVA_ADMIN',
 36  'CTXAPP',
 37  'XDBADMIN',
 38  'XDB_SET_INVOKER',
 39  'AUTHENTICATEDUSER',
 40  'XDB_WEBSERVICES',
 41  'XDB_WEBSERVICES_WITH_PUBLIC',
 42  'XDB_WEBSERVICES_OVER_HTTP',
 43  'OLAP_DBA',
 44  'ORDADMIN',
 45  'OLAP_XS_ADMIN',
 46  'CWM_USER',
 47  'OLAP_USER',
 48  'SPATIAL_WFS_ADMIN',
 49  'WFS_USR_ROLE',
 50  'SPATIAL_CSW_ADMIN',
 51  'CSW_USR_ROLE',
 52  'MGMT_USER',
 53  'APEX_ADMINISTRATOR_ROLE',
 54  'OWB$CLIENT',
 55  'OWB_DESIGNCENTER_VIEW',
 56  'XDBWEBSERVICES',
 57  'OLAPI_TRACE_USER',
 58  'PLUSTRACE',
 59  'OWB_USER'
 60* )