undefined reference to ,vtable for...

[chaturap]

Hi,

I'm trying to implement factory method pattern using C++ on Ubuntu 8.04 using gcc 4.2.

There are 3 major classes DBConnectionFac tory, DBConnector and OracleConnector (which is the derived class of DBConnector).

source in separate header and cpp files as below.


/* DBConnectionFac tory.h */

#ifndef _DBCONNECTIONFA CTORY_H
#define _DBCONNECTIONFA CTORY_H
#include <iostream>
#include "DBConnecto r.h"
using namespace std;

class DBConnectionFac tory
{
public:
static DBConnector* getConnector(st ring&);
};

#endif /* _DBCONNECTIONFA CTORY_H */

//=============== =============== =============== ===============

/* DBConnectionFac tory.cpp */

#include "DBConnectionFa ctory.h"
#include "DBConnecto r.h"
#include "OracleConnecto r.h"

DBConnector* DBConnectionFac tory::getConnec tor(string& dbName)
{
DBConnector* factory;

if(dbName=="ora cle"){
factory = new OracleConnector ();
}
else{
exit(1);
}
if(factory==0){
exit(1);
}
else{
return factory;
}
}

//=============== =============== =============== ===============

/* DBConnector.cpp */

#ifndef _DBCONNECTOR_H
#define _DBCONNECTOR_H
#include <iostream>
using namespace std;

class DBConnector
{
public:
// Pure virtual methods. Derived class(es) should implement these methods
virtual void init() = 0;
virtual void connect() = 0;
virtual void shutdown() = 0;

virtual ~DBConnector()
{

}
};

#endif /* _DBCONNECTOR_H */


//=============== =============== =============== ===============

/* OracleConnector .h */

#ifndef _ORACLECONNECTO R_H
#define _ORACLECONNECTO R_H
#include <iostream>
#include "DBConnecto r.h"
#include <occi.h>

using namespace std;
using namespace oracle::occi;

class OracleConnector : public DBConnector
{
private:
// commented...

public:
void init();
void connect();
void shutdown();
};

#endif /* _ORACLECONNECTO R_H */

//=============== =============== =============== ===============

/* OracleConnector .cpp */

#include <iostream>
#include "OracleConnecto r.h"

using namespace std;

void OracleConnector ::init(){
// code...
}

void OracleConnector ::connect(){
// code...
}

void OracleConnector ::shutdown(){
// code...
}

int main(){} // TODO: Remove this main() added for testing

When I try to compile DBConnectionFac tory.cpp it gives folowing error(s).

Command: g++ DBConnectionFac tory.cpp -I/opt/oracle/include -L/opt/oracle/lib -locci -lclntsh

Error:

/tmp/cc15eWsy.o: In function `OracleConnecto r::OracleConnec tor()':
DBConnectionFac tory.cpp:(.text ._ZN15OracleCon nectorC1Ev[OracleConnector ::OracleConnect or()]+0x16): undefined reference to `vtable for OracleConnector '
collect2: ld returned 1 exit status

I went through GCC FAQs but could not figure out the reason. Highly appreciate your feedback.

Thanks,

Chatura

[weaknessforcats]

This compiles fine with Visual Studio.NET 2008.

[newb16]

You don't link OracleConnector .o with your DBConnectionFac tory, but reference OracleConnector in it when create it
factory = new OracleConnector ();

It compiles ok if you merge all this stuff in one cpp file.

[chaturap]

Thanks for replying... I will try