ACE TAO Corba Ubuntu 10.4 undefined reference to CORBA::Object::_refcount_value()

Question

Hi,

I am having a few problems getting the example programs that come with the libTao provided in the package manager. I have used ace tao in the past with windows so have some experience with it already.

So far I have all the environment variables set, created a new projects for the "Simple Client" example. I can compile the .idl fine. When I then try to compile the client I get a linker error ...

Building target: CorbaTest
Invoking: GCC C++ Linker
g++ -Xlinker -Map -Xlinker txt.txt -Xlinker --cref -o"CorbaTest" ./src/EchoC.o ./src/EchoS.o ./src/Echo_Client_i.o ./src/Echo_I.o ./src/client.o -lACE -lTAO -lTAO_AnyTypeCode -lTAO_BiDirGIOP -lTAO_CodecFactory -lTAO_CosNaming -lTAO_DynamicAny -lTAO_EndpointPolicy -lTAO_DynamicInterface -lTAO_IFR_Client -lTAO_ImR_Client -lTAO_IORInterceptor -lTAO_IORTable -lTAO_Messaging -lTAO_ObjRefTemplate -lTAO_PI -lTAO_RTCORBA -lTAO_RTPortableServer -lTAO_PortableServer -lTAO_SmartProxies -lTAO_Strategies -lTAO_TypeCodeFactory -lTAO_Utils -lTAO_Valuetype -lTAO_CSD_ThreadPool -lTAO_TC -lTAO_TC_IIOP -lTAO_Compression -lTAO_ZlibCompressor
./src/EchoC.o:(.rodata._ZTV4Echo[vtable for Echo]+0xe0): undefined reference to `CORBA::Object::_refcount_value() const'
collect2: ld returned 1 exit status
make: *** [CorbaTest] Error 1

I cannot find anything online with regards to CORBA::OBbject_refcount_value() to point me in the direction of a library I might be missing. I have included all the recomended libraries from here http://www.dre.vanderbilt.edu/~schmi...libraries.html and still get the same error. This is example code that should compile and link against the supplied Tao distribution. Any ideas what I am missing? Oh and im using eclipse if it makes any difference.

Thanks :)

Answer 1

It's possible your linker is having trouble with the library order. You've got libACE first, followed by libTAO, etc. With some linkers if libA depends on libB, then libA should some before (i.e., to the left of) libB in the link. So, since TAO depends on ACE, try putting libTAO to the left of libACE. In fact, you might try reversing the order of the libraries in your link, since all of the libTAO_* libraries you have listed depend on libTAO.

Better yet, you might want to check out the free MPC tool that comes with ACE+TAO. It can generate trouble-free ACE+TAO Makefiles for most platforms. It lives in the $ACE_ROOT/bin directory and is well documented. See http://www.ociweb.com/products/mpc for info. I don't know how well it will work with Eclipse, but it might be worth a shot. Maybe you can edit code in Eclipse and compile from the command line.