On Mon, Feb 11, 2013 at 12:26 PM, Evan Huus <eapache@xxxxxxxxx> wrote:
> On Mon, Feb 11, 2013 at 11:01 AM, Dirk Jagdmann <doj@xxxxxxxxx> wrote:
>> To me the biggest advantage of transitioning to a C++ compiler is the
>> availability of std::string and std::list, std::set, std::map. They are so much
>> more convinient to use than equivalents from the glib or the alternatives
>> designed for Wireshark. Since the C++ STL classes allow a custom allocator we
>> can write C++ allocators for our ep_ and se_ (or the new wmem_) paradigms and
>> typedef Wireshark versions of the STL objects with these allocators. This would
>> be my biggest immediate benefit.
>
> That would be very nice, it's true.
On second thought, and after a little digging into how exactly STL
allocators work, they don't really support what we are currently doing
with emem/wmem. Specifically, they would only allow us to bulk-free
the underlying memory of classes, not bulk-destruct (which is also
necessary). This is a fairly strong argument that regardless of what
the API ends up doing, dissector internals should be limited to
C-style structs.
>> I don't advocate to redesign Wireshark into a C++ object/inheritance hell at
>> once, although with those "features" available new developments can/might/will
>> use them and over time we may have better code.
>>
>> Since the QT version is already using C++, I guess that simply building current
>> Wireshark with a C++ compiler is a no brainer. If we agree that this route is
>> worthwhile we could simply start building with C++ and develop some guidelines
>> how to proceed with new code, restructuring old code and maintaining/bugfixing
>> old code.
>>
>> The only caveat I can think of: if we build libdissectors with a C++ compiler
>> that might force other users of that library to switch to C++ as well (name
>> mangling etc).
>
> I think, at least to start, it would make sense to keep all of our
> library interfaces in C (so basically extern-C everything that's
> exposed). This prevents us from making use of a number of C++
> constructs, but we don't want to go massively changing API/ABI until
> we have a broad consensus that the benefits outweigh the costs.
>
> Evan
