Re: [csmith-bugs] missing return with --check-global

["Xuejun Yang" <jxyang@cs.utah.edu>]

Hi, Xavier,

Again I need to know which version of Csmith were you running: I run the
command "csmith --check-global -s 123" and did get a main function that
returns 0 at the end.

thanks,
-Xuejun

> 
> Dear Csmith developers,
> 
> [ A bit of background: this is the CompCert guy (Xavier Leroy)
> speaking.  I've been playing with Csmith this afternoon, with the idea
> of using it to test a reference interpreter for CompCert C's formal
> semantics, just like Rosu, Ellison and you have been doing with the
> kcc reference interpreter.  My reference interpreter is not yet 100%
> up to the task, but I'm getting interesting feedback already from
> Csmith-generated examples.  In the process, I found a few unexpected
> behaviors of Csmith that I'm taking the liberty to report, in separate
> messages.  Here is unexpected behavior #1. ]
> 
> When run with option --check-global, Csmith produces a "main" function
> that has no "return" at the end.  E.g. with --seed 123:
> 
> int main (int argc, char* argv[])
> {
>     func_1();
>     printf("checksum g_2 = %d\n", g_2);
>     printf("checksum g_3 = %d\n", g_3);
> }
> 
> This is undefined behavior and my reference interpreter balks at it.
> Could you just add "return 0;" at the end?  Thanks,
> 
> - Xavier