[R] linking other C++ libraries

[Sundar Dorai-Raj]

Samuel Kemp wrote:

> Hi,
> 
> I have written a little C++ program, which uses a third party library 
> called ANN (approximate nearest neighbours)....
> 
> #include "/home/sekemp/ann_0.2/include/ANN/ANN.h"
> 
> I have tried R CMD SHLIB ann.h myProgram.cc, although this compiles when 
> I load it into R I get the following message..
> 
> dyn.load("/home/sekemp/ann_0.2/ann.so")
> Error in dyn.load(x, as.logical(local), as.logical(now)) :
>        unable to load shared library "/home/sekemp/ann_0.2/GammaTest.so":
>  /home/sekemp/ann_0.2/GammaTest.so: undefined symbol: 
> _ZN10ANNkd_treeC1EPPdiii12ANNsplitRule
> 
> I get the same error when I dyn.load the myProgram.so aswell.
> 
> There is nothing wrong with the ann library as I have used it directly 
> in C++ using the compiler-linker thingy....
> 
> g++ myProgram.cc -I/home/sekemp/ann_0.2/include 
> -L/home/sekemp/ann_0.2/lib -lANN
> 
> Does anyone have any ideas?
> 

Looks like C++ name mangling. Did you wrap your code in extern "C" {}?

Regards,
Sundar