Re: [PATCH] fix some clang warnings

> It is not about the macro itself, but rather the callsites that do not
> return error, but call it for its printing side effect. It seems that
> clang -Wunused-value is OK with unused values from functions being
> discarded, but not with constants. So:
> 
>   int foo();
>   void bar()
>   {
>     foo(); /* ok */
>     1; /* not ok */
>     (foo(), 1); /* not ok */
>   }
> 
> The first one is OK (I think it would fall under -Wunused-result under
> either compiler). The middle one is an obvious error, and caught by both
> compilers. The last one is OK by gcc, but clang complains.