Gcc silently transforms a finite loop to an infinite one

[Robert Dewar]

On 11/29/2011 8:29 AM, Michael Matz wrote:

>> IMHO it would be better to issue a warning when a finite loop is
>> transformed to an infinite one (as a result of -ftree-vrp).
>
> -Wstrict-overflow gives a warning in this program.  This warning isn't
> active by default.  4.1 didn't yet have this warning IIRC.

I would tend to agree that when this transformation is applied, an
unconditional warning is appropriate. It's almost certainly indicative
of a bug, and indeed the character case of this report is such a common
case that I would look for it specifically and diagnose it (and
preferably make it "work").
>
>
> Ciao,
> Michael.