root/usr/src/tools/smatch/src/validation/pure-function.c

static __attribute__((__pure__)) int pure1(void)
{
        int i = 0;
        return i;
}

static __attribute__((__pure__)) void *pure2(void)
{
    void *i = (void *)0;
    return i;
}

/*
 * check-name: Pure function attribute
 */