Re: Some tests in gcc.c-torture rely on undefined behaviour?

[Robert Dewar <dewar at adacore dot com>]

Nicholas Nethercote wrote:
> Hi,
>
> I've been looking at the gcc.c-torture tests, it seems some of them rely 
> on undefined behaviour.  For example, 920612-1.c looks like this:
>
>   f(j)int j;{return++j>0;}
>   main(){if(f((~0U)>>1))abort();exit(0);}
>
> AIUI, this passes the largest possible positive integer to f(), which 
> then increments it, causing signed overflow, the result of which is 
> undefined. The test passes if signed overflow wraps.
>
> 930529-1.c is similar -- again the maximum positive integer is incremented.

i think it is fine 2 have these tests. ant gcc version failing them is suspicious