The impala bitcode reader/resolver is here: https://github.com/cloudera/Impala/blob/cdh5-trunk/be/src/co...

It also needs a special mcjit resolver: https://github.com/cloudera/Impala/blob/cdh5-trunk/be/src/co...

For those curious about background: https://blog.cloudera.com/blog/2013/02/inside-cloudera-impal...