VMD-L Mailing List

From: John Jumper (jumper_at_uchicago.edu)
Date: Thu Jan 10 2013 - 21:08:22 CST

When compiling the source for VMD on OS X Lion using clang, I
encountered the warning below. I am not familiar at all with this
source, but the code written certainly looks like a bug due to
mistaken operator precedence. Please disregard if I am not correct.

Compiling QuickSurf.C --> QuickSurf.o ...
QuickSurf.C:531:58: warning: operator '?:' has lower precedence than
'+'; '+' will be evaluated first [-Wparentheses]
  long volmemtexszkb = (volmemszkb + (voltexmap != NULL) ? 3*volmemszkb : 0);
                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
QuickSurf.C:531:58: note: place parentheses around the '+' expression
to silence this warning
  long volmemtexszkb = (volmemszkb + (voltexmap != NULL) ? 3*volmemszkb : 0);
                                                         ^
                        ( )
QuickSurf.C:531:58: note: place parentheses around the '?:' expression
to evaluate it first
  long volmemtexszkb = (volmemszkb + (voltexmap != NULL) ? 3*volmemszkb : 0);
                                                         ^
                                     ( )
1 warning generated.

Best regards,
John Jumper