To be able to use the upc keywords shared, you have to
use the command line option : "-fthreads"

upc_free does not exist in the current implemantation of the upc librairy.

The upc linker is not able to link correctly the function upc_barrier.
To use this function, you need to compile and link in one function without
generating intermediate object files.

Troubles with memory allocation using upc_local_alloc.