Re: [Boost-users] [serialization]conflicting declaration(BOOST_CLASS_EXPORT)

Subject: Re: [Boost-users] [serialization]conflicting declaration(BOOST_CLASS_EXPORT)
From: Robert Ramey (ramey_at_[hidden])
Date: 2008-09-24 16:09:12

> I have a simple example, which I attach. I use MinGW under XP.

what compiler version.

Do the serialization tests which use "EXPORT" also fail in your machine?
Try building them this bjam.  That is - try running the whole
serialization test suite.

If the all these serialization tests pass but your example fails, check to
see that the compil/link switches are the same in both cases.

Is there an environment similar to yours in the test matrix?  All tests
related to export passing except for one platform.

Robert Ramey

jens weller wrote:
> Jeff Flinn wrote:
>> jens weller wrote:
>>
>>> Jeff Flinn wrote:
>>>
>>>> jens weller wrote:
>>>>
>>>>> Robert Ramey wrote:
>>>>>
>>>>>> try the following re export:
>>>>>>
>>>>>> a) re-read the manual regarding boost class export
>>>>>
>>>>>
>>>>> I did, any points you think about?
>>>>>
>>>>>> b) Try using BOOST_CLASS_EXPORT only once.
>>>>>
>>>>>
>>>>>
>>>>> So far I thought after each class I could just set a
>>>>> BOOST_CLASS_EXPORT($classname),
>>>>> as far as its derived from a serializable class.
>>>>> So, how to use it "only once"?
>>>>> Should I put those all in one file instead? ("exportmodel.hpp"
>>>>> f.e.)
>>>>
>>>>
>>>>
>>>> Hi Jens,
>>>>
>>>> I think Robert means that BOOST_CLASS_EXPORT($classname) may only
>>>> be expanded once in your program for a particular class name. And
>>>> per the docs this expansion must occur within the context of all
>>>> archive types that will be used to serialize the class.
>>>>
>>>> So rather than placing these macro calls in headers(which may be
>>>> included in multiple translation units), place them in a cpp file
>>>> that first includes the desired archive headers. Typically this
>>>> would be in the class' implementation file. In the past I had
>>>> placed them all in a single file, but quickly found the MSVC7.1
>>>> compiler limits, and had to break them up into export1.cpp,
>>>> export2.cpp, ...
>>>>
>>>>
>>>> Jeff Flinn
>>>
>>>
>>> Unfortunately it does not work for me.
>>>
>>> "Die Anweisung "0x00411b4c" verweist auf Speicher in "0x000000000".
>>> Der Vorgang "written" konnte nicht auf den Speicher durchgeführt
>>> werden."
>>>
>>> thats what I get as soon as I compile in Releasemode.
>>> Debug Version runs without errors, so I guess the code is ok.
>>>
>>> My Export.cpp:
>>>
>>>
>>> #include <boost/archive/text_oarchive.hpp>
>>> #include <boost/archive/text_iarchive.hpp>
>>> #include "Include.hpp"
>>> #include "FileNode.hpp"
>>> #include "DirNode.hpp"
>>> #include "Observer.hpp"
>>>
>>> namespace codemodel
>>> {
>>> BOOST_CLASS_EXPORT( Include )
>>> BOOST_CLASS_EXPORT( FileNode )
>>> BOOST_CLASS_EXPORT( DirNode )
>>> BOOST_CLASS_EXPORT( ParentNode )
>>> //*/
>>> }
>>>
>>> I'm using SVN Version of boost, about a week old.
>>> I currently have no short example, but will try to get one working.
>>> Anything wrong with this code?
>>> Any hints why it fails in Releasemode?
>>
>>
>> Could be the code is being stripped from the release build?
>>
>> Sorry, meine deutsche rostig ist. :-) so I'm not positive of the
>> compile/link error your getting.
>>
>> Jeff
>
> The program compiles. It crashes directly at start up. With write to
> 0x00000000, which I guess simply is an uninitialised pointer some
> where in the guts of BOOST_CLASS_EXPORT.
>
> As I said release -> crash, debug -> works fine.
> Also removing the BOOST_CLASS_EXPORT Macros removes the crash. So I
> doubt some how that this happens in my own code.
>
> Also placing the B_C_E macros in the main file, makes it(partly) work
> again, but thats no solution, and no explanation why it crashes if
> there somewhere else. Also in my main program, this does not work.
>
> I have a simple example, which I attach. I use MinGW under XP.
>
> regards,
>
> Jens Weller
>
>
>
>
>
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