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Altera_Forum's avatar
Altera_Forum
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8 years ago

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

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?

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
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    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.