samba - Feb 1999 - Warning Messages during build

On SCO OpenServer 5.0.2 with SCO Development kit, during the make of samba
the following warnings are displayed can anyone shed any light ?

BUILD MESSAGES:
=============="smbd/open.c", line 620: warning: integer overflow
detected :op "<<"

"lib/utils.c ", line 2600: warning: integer overflow detected :op
"<<"
"lib/utils.c ", line 2613: warning: integer overflow detected :op
"<<"