Re: [boost] auto-link with gcc/windows

Subject: Re: [boost] auto-link with gcc/windows
From: Robert Ramey (ramey_at_[hidden])
Date: 2010-07-06 14:18:40

John Maddock wrote:

> My guess as to what's happening here is that one source file is seeing
> symbol X with a __declspec(dllexport) attribute because
> BOOST_SERIALIZATION_SOURCE is defined for that source, where as
> another source file is seeing the same symbol without the
> __declspec() attribute because BOOST_SERIALIZATION_SOURCE is not
> defined for it.  The result is that the two source files end up looking 
> for different mangled names
> for that symbol and hence the error.  The most consistent way to deal
> with this is to set BOOST_SERIALIZATION_SOURCE for all source the
> files.

Hmmm - I don't think that works.  In part because of the way code is
structured.

The serialization library is packaged as two DLL/libs:

serialization.dll

and

wserialization.dll

This was done so that those who don't use wide characters don't have
to carry around any useless code.  But wserialization depends upon
code included in serialization.dll.  So when a module from wserialization
compiles, functions defined in wserialization need to be exported
while functions defined in serialization.dll  need to be imported.  So I've 
had the
policy of onl including BOOST_SERIALIZATION_SOURCE in
those modules which implement functions to be exported.  I think
that is the correct policy.  Actually the situation is slightly more
complicated, but you get the idea.  I'm thinking that the situation has
been made somewhat confusing by the fact that autolinking headers
includes macros to make exported functions visible for MSVC
as well as Borland.  It's likely that there's some sort of conflict or 
interaction
with the new "visibility" setup.  I haven't had an opportunity to really
look into this yet so feel free to take these observations with a grain
of salt.

Robert Ramey

>
> HTH, John.
>
> _______________________________________________
> Unsubscribe & other changes:
> http://lists.boost.org/mailman/listinfo.cgi/boost