Re: symbol lookup error: undefined symbol

[Germán Diago <germandiago at gmail dot com>]

I noticed now that using ldd does not list libmylib as a dependency of
the executable. I think it should, shouldn't it?


2009/4/11 Germán Diago <germandiago@gmail.com>:
> Hello. I'm having problems with what it seemed to work before. I'm
> under ubuntu 9.04, gcc .4.3.3 compiler.
>
> I have a project in which I build a shared library.
> The shared library is later used ?in an executable.
>
> When I try to run the executable, once compiled, I get a strange error:
>
> It does not find some symbols from my shared library. I checked the
> library with the program nm.
> There are no undefined (relevant) symbols for my shared library there.
>
> However, in my executable, the following is shown with nm -u (I just
> copy here what it's relevant):
>
> ? ? ? ? U _ZN3ftr10Aplicacion11dibujarTodoER9SDL_Event
> ? ? ? ? U _ZN3ftr10Aplicacion11inicializarEv
> ? ? ? ? U _ZN3ftr10Aplicacion12addDibujableERKN5boost8functionIFvR9SDL_EventESaIvEEENS_15PrioridadDibujoE
> ? ? ? ? U _ZN3ftr10Aplicacion17refrescarPantallaEv
> ? ? ? ? U _ZN3ftr10Aplicacion8addTareaEPFvR9SDL_EventE
> ? ? ? ? U _ZN3ftr10Aplicacion8ejecutarEv
> ? ? ? ? U _ZN3ftr10AplicacionD1Ev
> ? ? ? ? U _ZN3ftr12MonitorDatos7dibujarER9SDL_Event
> ? ? ? ? U _ZN3ftr12MonitorDatosC1Ev
> ? ? ? ? U _ZN3ftr12MonitorDatosD1Ev
> ? ? ? ? U _ZN3ftr18ParseadorEscenario7parsearERKSs
> ? ? ? ? U _ZN3ftr18ParseadorEscenarioC1ERNS_9EscenarioE
> ? ? ? ? U _ZN3ftr18ParseadorEscenarioD1Ev
> ? ? ? ? U _ZN3ftr18ParseadorPersonaje7parsearERKSs
> ? ? ? ? U _ZN3ftr18ParseadorPersonajeC1ERNS_9PersonajeE
> ? ? ? ? U _ZN3ftr18ParseadorPersonajeD1Ev
> ? ? ? ? U _ZN3ftr9Escenario11inicializarEv
> ? ? ? ? U _ZN3ftr9Escenario7dibujarER9SDL_Event
> ? ? ? ? U _ZN3ftr9EscenarioC1Ev
> ? ? ? ? U _ZN3ftr9EscenarioD1Ev
> ? ? ? ? U _ZNK3ftr9Personaje7getPosXEv
> ? ? ? ? U _ZNK3ftr9Personaje7getPosYEv
>
>
> These symbols are from the library I compiled, and they appear as
> undefined in the executable, so when I try to execute
> my program, it fails.
>
> If I compile a Static library everything is ok, but I need to compile
> a shared library for other purposes.
>
>
> This compilation command is used to build files in my shared library:
>
> ?g++ -o build/linux2/release/libmylib/Utility.os -c -O3 -fPIC
> -D_GNU_SOURCE=1 -D_REENTRANT -DDATA_DIR=\"/usr/share/mylib/\"
> -DTIXML_USE_STL=YES -I/usr/include/python2.6 -I/usr/include/SDL
> -Ibuild/linux2/release/libmylib -Ilibmylib -Itinyxml
> libfollowtherabbit/Utility.cpp
>
> This is the link gcc command:
>
> g++ -o build/linux2/release/libmylib/libmylib.so -shared (all object
> files here and other libraries here)
>
> This is used for my executable:
>
> ?g++ -o build/linux2/release/src/myprogram
> build/linux2/release/src/myprogram.o -Lbuild/linux2/release/libmylib
> -Llibmylib -L/usr/lib -lmylib
> build/linux2/release/tinyxml/libtinyxml.a -lSDL_ttf -lSDL_mixer -lSDL
>
> Thanks for your help
>