Undefined behaviour in hotspot

[Omair Majid]

* David Chase <david.r.chase at oracle.com> [2014-04-21 13:53]:
> 
> On 2014-04-21, at 12:17 PM, Omair Majid <omajid at redhat.com> wrote:
> > I can ping them, but honestly, I wouldn't be surprised at all if the
> > only response I get is "no". I don't have any official communication
> > channels with them, so my input is not any different from anyone else's.
> > 
> > Can you elaborate on what flag/pragma you have in mind? Just something
> > to play nice with NULL pointers?
> 
> Not just null pointers.  Also optimizations that pretend that integer overflow
> doesn't happen (i.e., optimizations that change program behavior when it
> does) also need to be disabled.

My knowledge of C/C++ is fairly limited, so please bear with me. There
are a few relevant options already listed in 'man gcc':

-Wstrict-overflow=n
           This option is only active when -fstrict-overflow is active.
           It warns about cases where the compiler optimizes based on
           the assumption that signed overflow does not occur

-fwrapv
           This option instructs the compiler to assume that signed
           arithmetic overflow of addition, subtraction and
           multiplication wraps around using twos-complement
           representation. 

Do you mean others?

Thanks,
Omair

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