This is the mail archive of the cygwin mailing list for the Cygwin project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Lot of undefined symbols at link time, even with -l option on good libraries


problem seems coming from trailing @nn in library symbols.
cygwin linker don't know how to translate a reference like _FormatMessageA to _FormatMessageA@28
the calling convention ( C, Stdcall, C++, ... ) has effect only on underscore preceeding symbol name, not on @nn notation.


It seems there is no solutions to this problem, I will abandon cygwin to build my Ada application under windows :-(


Larry Hall a écrit :


At 12:15 PM 9/21/2004, you wrote:


I think you're right, it seems to be a problem with trailing underscore in function naming.
For example :

in /usr/lib/w32api/libkernel32.a we found :

 00000000 T _FormatMessageA@28
                  U __head_libkernel32_a
 00000000 I __imp__FormatMessageA@28

which is required by win32-winbase.o, result of the build of /usr/lib/gcc/win32ada/win32-winbase.adb
      U _FormatMessageA
      U _FormatMessageW
      U _GlobalReAlloc
      U _LocalReAlloc

The source code for this part is the following :
pragma Import (Stdcall, Doit, "FormatMessageA");

I try change it with pragma Import (C, Doit, "_FormatMessageA"); or things like that with no success.

May be it's the trailing @28 after symbol name which cause error, but I cannot control it ( it's DLL calling convention parameter size ). Compiler/linker should usually add or remove trailing @nn if necessary.

To answer your general questions, I'am building a large Ada application ( 200 source files ), using W32 API, with Win2000 GNAT Compiler.





Sorry, I know nothing about Ada and how it works. If the "pragma" statement
is supposed to take the place of the traditional function prototype in C/C++,
then I agree that it looks "OK" (again, based on my knowledge of Ada). But
the result is that it's looking for symbols that use the 'C' calling convention rather than the 'stdcall' calling convention. The libraries you
are linking to want the 'stdcall' calling convention (since it is the default for Windows). If you cannot get Ada to ask for the proper symbol, you could try using the '--enable-stdcall-fixup' option (for 'ld') to attempt to massage away the problem.




--
Larry Hall http://www.rfk.com
RFK Partners, Inc. (508) 893-9779 - RFK Office
838 Washington Street (508) 893-9889 - FAX
Holliston, MA 01746






--


*_Frédéric ORMANCEY_*

Atos Origin Systems Integration

/rue Ampère - BP 475 31315 Labège Cedex/

/Tel// /: 05 61 39 75 21
/Fax /: 05 61 39 16 65 frederic.ormancey@atosorigin.com <mailto:frederic.ormancey@atosorigin.com>
www.si.fr.atosorigin.com



=======================================================================================================
Ce message électronique est confidentiel. Il peut contenir des informations protégées par le secret professionnel, le secret de fabrication ou autres règles légales. Si vous recevez ce message par erreur, il vous est interdit de le reproduire ou de le distribuer en tout ou partie, ou de le divulguer de quelque manière que ce soit à quelque personne que ce soit. Nous vous prions de bien vouloir en informer Atos Origin, par téléphone ou par retour d'e-mail puis de détruire le message et toutes copies de votre système informatique.
Le contenu de ce message ne reflète pas nécessairement ni les opinions d'Atos Origin ni celles des membres de son groupe. Bien que l'émetteur de ce message ait fait tout son possible pour maintenir son système informatique sans virus, il ne peut garantir que cette transmission ne comporte aucun virus et il ne pourra être tenu pour responsable de quelque dommage que ce soit résultant de la transmission d'un virus.
=======================================================================================================





-- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]