Undefined reference during linking

Hi there,
I have trouble linking an simple code to the build libraries. Here is the code:
--------- demo_simple_02.cpp ----------
int main()
gp_Pnt p1 = gp_Pnt(0,0,0);
gp_Dir d1 = gp_Dir(0,0,1);
return 0;

I compile with:
g++ -I ~/ooc/install/include/opencascade/ -L ~/ooc/install/lib/ -lTKBin -lTKBinL -lTKBinTObj -lTKBinXCAF -lTKBO -lTKBool -lTKBRep -lTKCAF -lTKCDF -lTKDCAF -lTKDraw -lTKernel -lTKFeat -lTKFillet -lTKG2d -lTKG3d -lTKGeomAlgo -lTKGeomBase -lTKHLR -lTKIGES -lTKLCAF -lTKMath -lTKMesh -lTKMeshVS -lTKOffset -lTKOpenGl -lTKPrim -lTKQADraw -lTKRWMesh -lTKService -lTKShHealing -lTKStd -lTKStdL -lTKSTEP209 -lTKSTEP -lTKSTEPAttr -lTKSTEPBase -lTKSTL -lTKTObj -lTKTObjDRAW -lTKTopAlgo -lTKTopTest -lTKV3d -lTKVCAF -lTKViewerTest -lTKVRML -lTKXCAF -lTKXDEDRAW -lTKXDEIGES -lTKXDESTEP -lTKXMesh -lTKXml -lTKXmlL -lTKXmlTObj -lTKXmlXCAF -lTKXSBase -lTKXSDRAW demo_simple_02.cpp

and the first two errors I get are:

/tmp/ccldpw9f.o: In function `Standard_Transient::operator delete(void*)':
demo_simple_02.cpp:(.text._ZN18Standard_TransientdlEPv[_ZN18Standard_TransientdlEPv]+0x14): undefined reference to `Standard::Free(void*)'
/tmp/ccldpw9f.o: In function `Standard_DomainError::Standard_DomainError(Standard_DomainError const&)':
demo_simple_02.cpp:(.text._ZN20Standard_DomainErrorC2ERKS_[_ZN20Standard_DomainErrorC5ERKS_]+0x1f): undefined reference to `Standard_Failure::Standard_Failure(Standard_Failure const&)'

g++ (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0, cmake version 3.10.2.

One thing to note is that when I comment out gp_Dir d1 = gp_Dir(0,0,1); then this compiles.

Here is how I set things up: I used cmake to build the library. I started with not changeing anything there except the installation path. This produces shared libraries I am somewhat confident that the build was successful as the draw program worked. I saw the same errors as above. The I build static libraries. There I used

nm -gC *.a | grep Standard_Transient::Free

Adding an LD_LIBRARY_PATH did not help.

What provides Standard_Transient::Free and how do I add it to the build? If you need more information, let me know. I must be missing something obvious but I can not see it. If any one could point me in the right direction, that would be great. Thanks.

Kirill Gavrilov's picture

You should learn how your building toolchain works, including compilation, library linkage and library loading steps - currently they are missed up in your message.

g++ documentation describe your mistake here (your -lTKernel appears before your cpp - well, at least this is what I assume is the issue):

It makes a difference where in the command you write this option; the linker searches and processes libraries and object files in the order they are specified. Thus, ‘foo.o -lz bar.o’ searches library ‘z’ after file foo.o but before bar.o. If bar.o refers to functions in ‘z’, those functions may not be loaded.

You can avoid some low-level problems by using CMake or another building tools instead of calling g++ directly.

noop_152508's picture

Thank you.