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Re: Functional Developer UNICODE support + source?
Duane Rettig wrote:
> Rob Myers <robmyers@mac.com> writes:
> > C++ compiler manufacturers would need to agree on common name
> > mangling, vtable layout and exception handling conventions and they'd
> > then all need to implement them. This would allow C++ code compiled
> > with different versions of the same compiler, or C++ compilers from
> > different vendors, to call C++ code that isn't statically compiled
> > into the same compilation unit. It would then be relatively trivial to
> > allow other languages to join the party.
>
> As I understand it, C++ (either by standard or methodology) actually
> _encourages_ the divergence of mangling techniques per vendor, so as
> to render such an idea virtually useless (or at least very hard and
> C++ vendor specific). I heard this second-hand, so I don't know if
> it is common practice or actually mentioned in the C++ standard. The
> rationale is apparently that disparate mangling would reduce the
> chance of a name clash between vendors (not that I've ever heard of
> any two C++ vendors linking programs together :-).
And have you ever heard of two CL / Dylan / Scheme / ... vendors
linking programs together ? :-(
The lack of a common C++ name-mangling scheme is indeed
a blessing until a common ABI emerges. And the absence of an early
ABI can also be seen as a blessing, since it allowed some alternative
implementation techniques to be developped over the years before the
standardisation effort started.
Example:
"zero-cost" exception handling schemes are only now becoming the norm,
and those would have been hindered by earlier ABI standards.
(Now whether they are a blessing or a curse is another debate :-). )
> So in the CL world we speak to C++ as directly as possible by their
> only real direct interface: extern "C", or indirectly through COM,
> Corba, etc.
The "no-ABI" era may be slowly coming to an end. Cf.
http://www.codesourcery.com/cxx-abi/ and another message from me
in the same thread.
Good to have you posting in this newsgroup. I appreciate your postings
in comp.arch. I only wish it meant Franz were interested in Dylan...
Regards - Eric
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