9.65 __attribute__((unused)) variable attribute

Normally, the compiler warns if a variable is declared but is never referenced. This attribute informs the compiler that you expect a variable to be unused and tells it not to issue a warning if it is not used.

void Variable_Attributes_unused_0()
{
    static int aStatic =0;
    int aUnused __attribute__((unused));
    int bUnused;
    aStatic++;
}