Hello Dexter, and thank you for those files.
From them, we can see that you are using gcc 8.1 that by default supports C18 in C mode (I guess you are using another compiler on Linux).
We don’t yet support it (a ticket has just been created about that), which is why you see this message. Since C11 and C18 are very similar, though, you should not have any issue and can just ignore that message.
However, we advise you not to update your CFamily plugin to the 6.x for the time being, since the message that see has been moved to a hard error, which will fail your analysis.
Another way to go would be to change your build script to specify
-std=c11 on your compiler command line. It would work both with no message (CFamily 5.x) and no error (CFamily 6.x), as well as being more accurate about what version of the standard you use for building.
Hope this helps,