Re: [avr-gcc-list] using exceptions

[Gabriel Dos Reis]

On Tue, May 1, 2012 at 8:04 AM, Georg-Johann Lay <address@hidden> wrote:
> Gabriel Dos Reis schrieb:
>>
>> Georg-Johann Lay wrote:
>>>
>>> Kövesdi György schrieb:
>>>
>>>> I am using avr-g++ for building my projects for avr and i am
>>>> happy with it. :-)
>>>> But i would need exception support, and could not find how to
>>>> get it work. I found some mails in the archive (dated many
>>>> years ago) about possibilityof building libstdc++ or libsupc++
>>>>
>>>> with exception support, but could not find how to do it.
>>>> Reportedly it uses 10...20 kbytes of text, which would be acceptable.
>>>>
>>>> Currently i have gcc 4.6.2 sources, and have tried the options
>>>> --enable-sjlj-exceptions,
>>>> --with-exceptions, --with-rtti, --enable-libstdc++, etc... no one
>>>> helped.
>>>
>>>
>>> libstdc++ is turned off in configury, for example configure.ac reads
>>>
>>> # Disable libstdc++-v3 for some systems.
>>> case "${target}" in
>>> [...]
>>> avr-*-*)
>>>  noconfigdirs="$noconfigdirs target-libstdc++-v3"
>>>  ;;
>>> esac
>>>
>>> This is current trunk. There were some changes not very long ago.
>>
>>
>> Would it be reasonable to expect at least libsupc++?
>> That would be a useful start...
>
>
> IMHO extending what avr-gcc/avr-g++ can do is reasonable and
> appreciated.
>
> However, avr notoriously is short of developers, and if some
> problems pop up, there is nobody who would fix it.
>
> For example, PR50925 could block a build, or it might be the
> case that unwinding does not work properly.
>
> I am not familiar with C++, it's a dreaded language I always
> avoided.  If I need to operate on a "big" system, I use Java
> or Python, and I am in the happy situation not to have to
> program big GUIs that base on C++.
>
> Presumably, exception/unwind support could be made much more
> efficient with avr-specific unwind info, but obviously
> noone ever tried to get it to work.
>
> Johann

Johann, thanks for elaborating.

My recent interests in AVR grew out of educational and research
activities -- as I explained in a relatively recent post on libstdc++.  I am
still learning AVR and its toolsets but I can definitely help with the C++ part.

We are in the situation where we would like to compile a restricted
subset of Haskell to AVR via C++ intermediate codes.

I will have a look at PR50925.

-- Gaby