[ECOS] C++ standard libraries

[ECOS] C++ standard libraries

[Colin Spier]

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Hi,

I'm currently using eCos 1.3.1 configured as a Linux synthetic target. I've
built
the binutils & gcc tool chain as described in the documentation, but this
does not seem to have given me any standard C++ library support (in the
first instance, I want to be able to use iostreams).

Is it possible to build/use C++ libraries with eCos? Any pointers gratefully
accepted!

Colin.



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Re: [ECOS] C++ standard libraries

[Jonathan Larmour]

Colin Spier wrote:
> 
> I'm currently using eCos 1.3.1 configured as a Linux synthetic target. I've
> built
> the binutils & gcc tool chain as described in the documentation, but this
> does not seem to have given me any standard C++ library support (in the
> first instance, I want to be able to use iostreams).
> 
> Is it possible to build/use C++ libraries with eCos? Any pointers gratefully
> accepted!

C++ libraries are not supported in eCos yet. It would take some work to
"port" C++ libraries to eCos. It's something we're intending to do but
haven't yet. If anyone else wanted to start, we'd be interested in talking
to them :-).

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault

RE: [ECOS] C++ standard libraries

[Colin Spier]

Do you think that there is a significant amount of work involved?

Where might one start?

Colin.
--
Colin Spier
PipingHot Networks Ltd.
mailto:colin.spier@pipinghotnetworks.com
http://www.pipinghotnetworks.com




> -----Original Message-----
> From: jlarmour@cygnus.co.uk [ mailto:jlarmour@cygnus.co.uk]On Behalf Of
> Jonathan Larmour
> Sent: 11 September 2000 04:35
> To: Colin Spier
> Cc: ecos-discuss@sourceware.cygnus.com
> Subject: Re: [ECOS] C++ standard libraries
>
>
> Colin Spier wrote:
> >
> > I'm currently using eCos 1.3.1 configured as a Linux synthetic
> target. I've
> > built
> > the binutils & gcc tool chain as described in the
> documentation, but this
> > does not seem to have given me any standard C++ library support (in the
> > first instance, I want to be able to use iostreams).
> >
> > Is it possible to build/use C++ libraries with eCos? Any
> pointers gratefully
> > accepted!
>
> C++ libraries are not supported in eCos yet. It would take some work to
> "port" C++ libraries to eCos. It's something we're intending to do but
> haven't yet. If anyone else wanted to start, we'd be interested in talking
> to them :-).
>
> Jifl
> --
> Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44
> (1223) 728762
> "Plan to be spontaneous tomorrow."  ||  These opinions are all my
> own fault

Re: [ECOS] C++ standard libraries

[Jonathan Larmour]

Colin Spier wrote:
> 
> Do you think that there is a significant amount of work involved?
> 
> Where might one start?

I think it's several weeks worth of work.

The first problem is that libstdc++ is integrated with the compiler - and
eCos is not around at compiler build time. Therefore the first step is to
ensure that what gcc builds at compiler build time will work with eCos, no
matter what the configuration (more or less).

libstdc++ relies heavily on exceptions. But exceptions are not thread-safe
by default - gcc would have to have work done on it to make it thread-safe
in eCos. The real challenge here is that since eCos is configurable, it
needs to do the right thing when the eCos kernel is not present either!

The other area to pay attention to is libio - libstdc++ requires libio. The
difficulty is that to make libstdc++ standards-compliant, I/O from
libstdc++ and I/O from normal libc stdio functions must be interleaved.
This means that they must use the same implementation. libstdc++ can only
work with libio, so the issue becomes one of integrating libio and eCos.

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault

Re: [ECOS] C++ standard libraries

[Bart Veer]

>>>>> "Jifl" == Jonathan Larmour <jlarmour@redhat.com> writes:

    Jifl> Colin Spier wrote:
    >> 
    >> Do you think that there is a significant amount of work involved?
    >> 
    >> Where might one start?

    Jifl> I think it's several weeks worth of work.

    <snip lots of good information>

For more details on libstdc++ development and mailing lists you may
want to look at http://sources.redhat.com/libstdc++/ , although the
code has now been incorporated into the mainline gcc sources.

Another possible concern is that eCos itself is currently compiled
with -fno-rtti -fno-exceptions. This could give problems if you start
mixing eCos and libstdc++ header files, since the latter will
definitely require exceptions and probably rtti as well. It is
possible that eCos will just work if you build it with rtti and
exceptions, but that is untested and obviously there would be some
code size penalties.

Bart Veer // eCos net maintainer

Re: [ECOS] C++ standard libraries

[Dave Vogel]

We have successfully ported parts of the stdc++ (STL) library for eCos using the
STLPort version and configuring  no exceptions and no iostreams.   It was a
trivial (less than 1 day) port to do.

The STLPort library is at http://www.stlport.org/  .

-dave-

Bart Veer wrote:

> >>>>> "Jifl" == Jonathan Larmour <jlarmour@redhat.com> writes:
>
>     Jifl> Colin Spier wrote:
>     >>
>     >> Do you think that there is a significant amount of work involved?
>     >>
>     >> Where might one start?
>
>     Jifl> I think it's several weeks worth of work.
>
>     <snip lots of good information>
>
> For more details on libstdc++ development and mailing lists you may
> want to look at http://sources.redhat.com/libstdc++/ , although the
> code has now been incorporated into the mainline gcc sources.
>
> Another possible concern is that eCos itself is currently compiled
> with -fno-rtti -fno-exceptions. This could give problems if you start
> mixing eCos and libstdc++ header files, since the latter will
> definitely require exceptions and probably rtti as well. It is
> possible that eCos will just work if you build it with rtti and
> exceptions, but that is untested and obviously there would be some
> code size penalties.
>
> Bart Veer // eCos net maintainer