Stop Pin Not Connected Warning

I think, the only way to supress the warning for specific pins is to actually connect logic to it. It only works, if you can afford to use at least one pin as logic output, e.g.

outpin <= inpin1 OR inpin2 OR inpin3;

If no output depends on the inserted dummy logic, it will be removed by the design compiler and you get a warning as well. There may be another solution by connecting the dummy logic output to a signal declared "virtual", but I didn't test. I must admit, that I don't have this kind of problems, because I accept to get plenty of warnings for various things. But I basically understand the idea of sorting out all meaningless warnings to see the serious ones.