gxlc and gxlc++ return codes

Like other invocation commands, gxlc and gxlc++ return output, such as listings, diagnostic messages related to the compilation, warnings related to unsuccessful translation of GNU options, and return codes. If gxlc or gxlc++ cannot successfully call the compiler, it sets the return code to one of the following values:

40
A gxlc or gxlc++ option error or unrecoverable error has been detected.
255
An error has been detected while the process was running.