On 7/31/2015 12:27 PM, Óscar Fuentes wrote: > Edward Diener <eldlistmaili...@tropicsoft.com> > writes: > >>> Calling a virtual member requires an access to the vtable of the class. >>> The vtable is defined on the dll that contains the class' code. If the >>> class is not exported, the vtable is not exported. The errors you are >>> seeing is the linker complaining about the missing vtable. >> >> So you are saying that any class with virtual functions must have the >> class itself exported rather than the individual member functions when >> using gcc ? Because with VC++ that is not the case, so it must be an >> issue with gcc on Windows. > > Not sure what VC++ does, exactly, but this: > > https://msdn.microsoft.com/en-us/library/81h27t8c.aspx > > /quote > > If you export one virtual function in a class, you must export all of > them, or at least provide versions that the client can use directly. > > If you have a class in which you are using selective member > import/export with virtual functions, the functions must be in the > exportable interface or defined inline (visible to the client). > > /end quote > > seems to say that you can't export some selected virtual members defined > in .cpp files and hide the rest of the class.
In my example all declared virtual functions are exported/imported. Please note that all versions of VC++, from 8 through the recent 14, have no problems compiling/linking the two shared libraries. VC++ does not require that implicit compiler-generated functions be exported/imported. It just works as is with what you declare and define. But of course mingw-64/gcc/ld does have these problems. Yet I keep hearing that this is somehow my fault rather than that of mingw-64/gcc/ld. No doubt I am supposed to figure out the voodoo which will cause mingw-64/gcc/ld to work. Even when I ask where to report this problem I am shaken off as if I have done something wrong rather than that the mingw-64/gcc/ld compile-link system is broken in some way when it refuses to link the second shared library. ------------------------------------------------------------------------------ _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
