TCHAR porting issues while porting from VC6 to VC8

Rajesh_Parameswaran

Hi all, I'm using Visual Studio 2005. I have a workspace in visual C++ 6.0 which provides a set of library functions[DLL]. I have a client application which uses one of the function in the library. This client was working perfectly in VC6.0, but when I ported to VC8, it started showing link error: Signature of the Function in the library[DLL] Header: ULONG sendInfo(const bool isRequest, TCHAR pParameters[MESSAGES_PARAMS][MESSAGE_SIZE], ULONG netCallId); Implementation of the Function in the library[DLL] Source: ULONG NIHAI_TAPI::sendInfo(const bool isRequest, TCHAR pParameters[MESSAGES_PARAMS][MESSAGE_SIZE], ULONG netCallId) { .... .... .... } Client Application Call: TCHAR messageParameters[MESSAGES_PARAMS][MESSAGE_SIZE]; ULONG netCallId; bool request; returnCode = tapiConnection.sendInfo(request, messageParameters, netCallId); But I'm getting a link error: nihai_worker.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: unsigned long __thiscall NIHAI_TAPI::sendInfo(bool,unsigned short (* const)[81],unsigned long)" (__imp_?sendInfo@NIHAI_TAPI@@QAEK_NQAY0FB@GK@Z) referenced in function "private: unsigned long __thiscall NIHAI_Worker::sendToTAPI(unsigned int,unsigned short (* const)[81],unsigned long)" (?sendToTAPI@NIHAI_Worker@@AAEKIQAY0FB@GK@Z) Kindly suggest a resolution for the above problem. Thanks in Advance. regards, Rajesh

Iain Clarke Warrior Programmer

One thing I know (there are soooome others) is that VC6 defaulted to not-unicode, and VC8 defaults to unicode. TCHAR means different things depending on the defines. So your program could be thinking TCHAR = wchar_t (ie, short), while the lib you're linking against was compiled with TCHAR = char, and the two decorated functions no longer match... So, to resolve it, you need to make sure both of your chunk of codes agree on what TCHAR means. Iain.

Plz sir... CPallini CPallini abuz drugz, plz plz help urgent.

CPallini

It seems a UNICODE vs ANSI build conflict, i.e. VC8 project makes UNICODE builds by default, while VC6 makes ANSI ones. Possibly you have a ANSI DLL and a UNICODE client. Try to change the client setting: choose Project->Properties menu item, then select Configuration Properties->General node and finally change the Character Set switch. :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

CPallini

u 2 fast -> i 2 drugz. :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

Iain Clarke Warrior Programmer

Well, I'm waiting for a colleague to finish a bit of work so I can carry on, so I'm pouncing for a little while. And I like to race you. Of course, while I was typing my last response, Cedric wrote a better and faster answer than me. Boo Cedric, Boo! Iain. ps, Noone's delivered your urgent drugs yet?

Plz sir... CPallini CPallini abuz drugz, plz plz help urgent.

Cedric Moonen

Iain Clarke wrote:

Of course, while I was typing my last response, Cedric wrote a better and faster answer than me. Boo Cedric, Boo!

Why don't we have a devil emoticon when we need it ? ;P

Cédric Moonen Software developer
Charting control [v1.4]

CPallini

Iain Clarke wrote:

Boo Cedric, Boo!

Definitely! That guy is too smart.

Iain Clarke wrote:

ps, Noone's delivered your urgent drugs yet?

Nope my friend...But since you are such a nice guy, ...plz plz plz urgent!!! :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

Cedric Moonen

CPallini wrote:

Definitely! That guy is too smart.

Well, it seems that you really abuse drugs :rolleyes:

Cédric Moonen Software developer
Charting control [v1.4]

Rajesh_Parameswaran

Hi Pallini and Iain, Thanks for your response. But I still have that error. Both the Characterset are set to the following: Character Set: Use Unicode Character Set Treat wchar_t as Built-in Type: No(/Zc:wchar_t-)\ thanks and regards, Rajesh

Rajkumar R

sorry for the silly question, did you linked to the import library.

CPallini

Rajesh_Parameswaran wrote:

Hi Pallini and Iain,

Since it is a reply to a Cedric post, I assume you're looking for the widest audience. :laugh:

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

Rajesh_Parameswaran

Yes Rajkumar, I have linked to the import library. thanks in advance, regards, Rajesh

Iain Clarke Warrior Programmer

Coming back your original question, go back to basics. Write a function such as:

int HowBigIsATCHAR (TCHAR i_is_a_letter)
{
return sizeof (i_is_a_letter);
}

not forgetting to use dllimport / export. Try using it in a your client program. See if you get link errors, and also what size it gives you. The TCHAR thing may be a blind alley, and you are having linking trouble with constant sizeed arrays. I've never passed a big array be value before... Try passing it as TCHAR **, and see if that helps? Iain.

Plz sir... CPallini CPallini abuz drugz, plz plz help urgent.

Rajkumar R

you may inspect the import library for the symbol may be this( [libexplorer addin^], [libdump^]) tools helps or by simply open in binary editor. But basically these meant the symbol are not properly created in the import library, possibly check dllexport declarator is used for the class in the DLL class declaration.

Rajkumar R

Actually i saw that was replied to you, but when OP had seen world is behind "Plz sir slow down", he moved it there. :)

CPallini

Possibly. :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke