Any body an idee what #define USE_ARG(x) { x = x; } does?

Altera_Forum · ‎01-31-2018

Hello,

i am using a cyclone with a nios system and tse_mac.

Now unfortunatly i had to port the system from 12.1 to 17, because the modules are damned not reverse compatible!

But now i have the et_arp.c file whitch is different from my last version in that there is an added line with

USE_ARG(eth);

where eth is a char *.

the definition of USE_ARG:

#define USE_ARG(x) { x = x; }

does anybody know what this macro does?

First I thought, that it is done to not be forced to cast different variables. But normally the compiler would anyway generate an errror?

Altera_Forum · ‎02-08-2018

Does the function actually use the eth argument? I've seen this kind of macros in some source code where a function doesn't use one of the arguments, to prevent the "unused argument" warning from the compiler.