[Iverilog-devel] NULL file descriptor or MCD

[Cary R. <cy...@ya...>]

It looks like Icarus along with at least one of the Big-3 simulators allows, without warning, the various file I/O system tasks/functions to accept a NULL (0) file descriptor/MCD. I can see this as helpful if you want to disable output by just setting the FD/MCD to zero, but it could be an issue if the $fopen failed and the user did not check so having a warning would be beneficial for that. We do print a warning for an invalid non-zero FD/MCD.

So should a zero FD/MCD print a warning or do we just want it to return as if nothing happened?
I tend to like the warnings, but I'm not certain if there is an easy way to disable MCD output without using the zero value. Should $fclose be handled differently?

Thoughts/suggestions appreciated.

Thanks,
Cary