Hello,
I am running into the "Error in dyn.load [...] unable to load shared object
['/tmp/...'] undefined symbol [_...]" error; however it is only happening
with one particular Rcpp function, which I find puzzling. Here is my .cpp
file containing two functions - I can compile the first one without any
issue (in its own file), but the second brings about the noted error
message:
#include <Rcpp.h>
#include <vector>
#include <string>
#include <algorithm>
// [[Rcpp::plugins(cpp11)]]
/*
* Works fine.
*/
struct checkTwo {
public:
checkTwo(const std::string& s1_, const std::string& s2_)
: s1(s1_), s2(s2_) {}
int operator() (std::string x1, std::string x2) {
return (s1==x1 && s2==x2 ? 1 : 0);
}
private:
std::string s1;
std::string s2;
};
// [[Rcpp::export]]
int count_if_if(const Rcpp::DataFrame& df,
const std::string& c1,
const std::string& c2)
{
std::vector<std::string> vc1 = df["C1"];
std::vector<std::string> vc2 = df["C2"];
int N = df.nrows();
std::vector<int> vcount;
vcount.resize( N );
std::transform(vc1.begin(),vc1.end(),vc2.begin(),vcount.begin(),checkTwo(c1,c2));
int total = std::accumulate(vcount.begin(),vcount.end(),0);
return total;
}
/*
* Does not compile.
*/
struct trackIdx {
public:
trackIdx(const std::string& s1_, const std::string& s2_)
: s1(s1_),s2(s2_) {}
int operator() (std::string x1, std::string x2) {
tracker++;
return ((s1==x1 && s2==x2) ? (tracker-1) : -1);
}
private:
std::string s1;
std::string s2;
static int tracker;
};
// [[Rcpp::export]]
std::vector<int> mc_index(const Rcpp::DataFrame& df,
const std::string& c1,
const std::string& c2)
{
std::vector<std::string> vc1 = df["C1"];
std::vector<std::string> vc2 = df["C2"];
int N = df.nrows();
std::vector<int> vcount;
vcount.resize( N );
std::vector<int> result;
result.resize( N );
std::transform(vc1.begin(),vc1.end(),vc2.begin(),vcount.begin(),trackIdx(c1,c2));
std::copy_if(vcount.begin(),vcount.end(),result.begin(),
[](int i) -> bool {
return !(i<0);
});
return result;
}
The above functions (only "count_if_if" at the moment) can be tested like
this:
Df <- data.frame(
C1=rep(LETTERS[1:4],each=15),
C2=as.character(rep(rep(1:3,each=5),4)),
C3=rep(rep(1:3,each=5),4),
stringsAsFactors=FALSE)
##
count_if_if(Df,"B","3")
##
# mc_index(Df,"B","3")
The exact error message I am getting is:
Error in
dyn.load("/tmp/Rtmpw7VSkV/sourcecpp_27046ca49cd4/sourceCpp_67600.so") :
unable to load shared object
'/tmp/Rtmpw7VSkV/sourcecpp_27046ca49cd4/sourceCpp_67600.so':
/tmp/Rtmpw7VSkV/sourcecpp_27046ca49cd4/sourceCpp_67600.so: undefined
symbol: _ZN8trackIdx7trackerE
and judging by the last bit, "undefined symbol: _ZN8trackIdx7trackerE", it
looks like my "trackIdx" function object is the source of the problem.
I have tested this on two different platforms -
my network server running CentOS 7:
R version 3.1.1
Platform: x86_64-redhat-linux-gnu (64-bit)
Rcpp_0.11.3
and my laptop running Ubuntu 14.04:
R version 3.0.2
Platform: x86_64-pc-linux-gnu (64-bit)
Rcpp_0.11.2
Both of these machines use a reasonably up-to-date version of g++ that
supports c++11 (although I don't think this has anything to do with the
issue). I have never had any problems compiling Rcpp functions on either of
these platforms, yet the second function object & Rcpp function above
produce the same error on each machine. If anyone can explain what is going
wrong and/or suggest how to correct the problem with the above code I would
appreciate it very much.
Thank you,
Nathan Russell
_______________________________________________
Rcpp-devel mailing list
Rcpp-devel@lists.r-forge.r-project.org
https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
