The LabVIEW block diagram is the source code.
It is compiled through the LabVIEW environment into a format suitable for running.
It does not go through an interim conversion to another language before it gets compiled, so
there is no other source code. The actual vi breaks down into 4 parts :
Front panel
Block diagram
Code (diagram compiled to machine code)
Data (control and indicator values, default data, diagram constant data, and so on)
Thanks
Sacha Emery
National Instruments (UK)
// it takes almost no time to rate an answer