Re: [C/C++ PATCH] Improve -Wlogical-op (PR c/63357)

[Marek Polacek <polacek@redhat.com>]

On Sat, Apr 25, 2015 at 10:18:59PM +0200, Gerald Pfeifer wrote:
> In case this example feels too contrived (even though it is an
> excerpt of Wine code), we now also warn about the following where
> the two types and variables are defined in different places and
> the size of one is set implicitly:
> 
>   typedef int r_fun_t (int);
> 
>   r_fun_t * text_funcs[] = {0,0,0};
> 
>   int report (unsigned t)
>   {
>     typedef int s_fun_t (long, char);
> 
>     static s_fun_t * GUI_funcs[3];
> 
>     return (t < sizeof text_funcs / sizeof text_funcs[0] &&
>             t < sizeof GUI_funcs / sizeof GUI_funcs[0]);
>   }
> 
> (I also filed this as https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65891
> so that we keep track.)

I'm afraid there isn't an easy solution to this; the problem is that we fold
sizeof early, so the warning sees 

  t < sizeof 4 && t < 4

and warns.  Maybe using SIZEOF_EXPR would help...

	Marek