C++ Linking error

Question

I have multiple classes connected by hxx header files and inheritance.This is all about OS simulation. I compiled them individually to see if i get any syntax errors but that was not the case.instead when i compile my main driver osTester.cxx i get linking error like this

#include <iostream>
#include <ostream>
#include <vector>
#include<string>
//#include <boost/shared_ptr.hpp>
#include "OS.hxx"
#include "Ram.hxx"
#include "Cpu.hxx"
#include "HardDisk.hxx"
#include "JobCreationFactory.hxx"
#include "Mouse.hxx"
#include "Monitor.hxx"
#include "Keyboard.hxx"

using namespace std;
typedef vector<int>LISTOFINT;
typedef LISTOFINT::iterator INT_ITER;

//namespace bo=boost;
//using bo::shared_ptr;
/* This is the main driver of the simulation,it makes all simulated devices available 
 and ready for use before operating system takes over(osTakeOver())
 */

int main(){
    
    int numberOfJobs = 0;
    bool simulate = false;
    string start;
    LISTOFINT schedulingAlgorithms; // 1 for SJF(Shortest Job first) and 2:for RR(Round Robbin)
    LISTOFINT numberOfResourcesAvailable;
    int mouseAvailable;
    int monitorAvailable;
    int keyboardAvailable;
    HardDisk HD;
    OS myOS;
    Cpu myCpu;
    Ram myRam;
    Mouse myMouse;
    Monitor myMonitor;
    Keyboard myKeyboard;
    JobCreationFactory j;
    //j.test();
    j.createFiles(HD);
    j.createJobs(HD);
    
    //set defaut number of jobs to be used in the simulation .. allow user to input number of jobs
    cout << "Enter number of Jobs to be used in the simulation (eg 40000) followed by space then  'S' for Start:";
    while (cin >> numberOfJobs >> start && !simulate) {
        simulate = true;
        HD.setNumberOfJobs(numberOfJobs);
    }   
    cout << "Enter the number of processes that a mouseQ can handle:(say 6)";
    cin >> mouseAvailable;
    cout << "Enter the number of processes that a monitoQ can handle:(say 7)";
    cin >> monitorAvailable;
    cout << "Enter the number of processes that a keyboardQ can handle:(say 8)";
    cin >> keyboardAvailable;
    numberOfResourcesAvailable.push_back(mouseAvailable);
    numberOfResourcesAvailable.push_back(monitorAvailable);
    numberOfResourcesAvailable.push_back(keyboardAvailable);
    //setAvailable Resources
    myOS.setAvailable(numberOfResourcesAvailable);
    
    /*simulate based on SJF then RR using the same number of resources then compare results
     *repeating the same algorithm a few more times would give a better comparison since this simulation
     *is entirely based on random number generation
    */
    schedulingAlgorithms.push_back(1);
    schedulingAlgorithms.push_back(2);
    INT_ITER sBegin = schedulingAlgorithms.begin();
    INT_ITER sEnd = schedulingAlgorithms.end();
    
    //at this point all devices are ready so an assumption can be made that 
    //BIOS has successfully checked devices hence BIOSdone = true
    //once everything is ready BIOS Loads OS
    
    for (; sBegin != sEnd; ++sBegin) {// for both algorithms
        myOS.setSchedulingAlgorithm(*sBegin);
        myOS.osTakeOver(HD,myRam,myCpu,myMouse,myMonitor,myKeyboard);
    }
    //for now the smulation progress will be seen on the console
    
    return 0;
    
}

I have tried using CMake but i still get the following error

Linking CXX executable osTester
Undefined symbols:

  "JobCreationFactory::createFiles(HardDisk)", referenced from:
      _main in osTester.cxx.o
  "OS::setAvailable(std::vector<int, std::allocator<int> >)", referenced from:
      _main in osTester.cxx.o
  "OS::osTakeOver(HardDisk, Ram, Cpu, Mouse, Monitor, Keyboard)", referenced from:
      _main in osTester.cxx.o
  "HardDisk::setNumberOfJobs(int)", referenced from:
      _main in osTester.cxx.o
  "OS::setSchedulingAlgorithm(int)", referenced from:
      _main in osTester.cxx.o
  "JobCreationFactory::createJobs(HardDisk)", referenced from:
      _main in osTester.cxx.old: symbol(s) not found

collect2: ld returned 1 exit status
make[2]: *** [src/osTester] Error 1
make[1]: *** [src/CMakeFiles/osTester.dir/all] Error 2
make: *** [all] Error 2

Please help!!!

Update:

I have JobCreationFactory::createFiles in cxx and prototype in .hxx.

I really don't understand the main problem. Please refer to the following Jobcreationfactory.cxx and .hxx respectively, and osTester.cxx (included in earlier post). I tried invoking a method from different class say OS and I get the same linking error.

#include<iostream>
#include<sstream>
#include<vector>
#include<algorithm>
#include "random.hxx"
#include "Jobs.hxx"
#include "HardDisk.hxx"
#include "File.hxx"

//using namespace std;
//typedef vector<int> LISTOFINT;
//LISTOFINT::iterator INT_ITER;

class JobCreationFactory{
    int numOfJobs;
    int numOfFiles;
    int time;
    int size;
    LISTOFINT header;
    
    JobCreationFactory()
    :numOfJobs(0),time(0),size(0)
    {
    }
    
     int getNumberOfJobs() 
    {
        return numOfJobs;
    }
    
     void createFiles(HardDisk hd)
    {   string file = "File";
        string intval;
        stringstream ss (stringstream::in | stringstream::out);
        RandomSeq r1(10000, 20000);
        numOfFiles = r1();
        RandomSeq r2(10, 100);
        for(int j = 0; j<=numOfFiles; j++ )
        {
            ss << j+1;
            ss >> intval;
            file.append(intval);
            hd.storeFiles(File(file,r2()));
        }
    }
    
     void createJobs(HardDisk hd)
    {
        string job = "Job";
        string intval;
        stringstream ss (stringstream::in | stringstream::out);
        RandomSeq r1(60000,70000);
        numOfJobs = r1();
        int instructionException = (int)(0.1 * numOfJobs);
        
        for (int i = 1; i < getNumberOfJobs()+ 1; i++) 
        {
            RandomSeq r1(0, 2);
            RandomSeq r2(0, numOfFiles);
            size = assignSize(); 
            time = assignTime(size);
            setHeader();
            ss << i;
            ss >> intval;
            job.append(intval);
            Jobs newJob(job,size, time, header,r1());
            if(i%instructionException == 0)
            {
                newJob.setInstructionException(true);
            }
            for(int k = 0; k<newJob.getNumberOfFiles();k++)
            {
                newJob.associateJobWithFiles(k, r2());
            }
            hd.storeJobs(newJob);
        }
    }
    
     int assignSize()
    {
        RandomSeq r1(500,5000);
        int size = r1();
        return size;
    }
    
     int assignTime(int size)
    {
        int time =0;
        RandomSeq r1(10,20);
        RandomSeq r2(20,30);
        RandomSeq r3(30,40);
        RandomSeq r4(40,50);
        RandomSeq r5(50,60);
        RandomSeq r6(60,70);
        RandomSeq r7(70,80);
        RandomSeq r8(80,90);
        RandomSeq r9(90,100);
        
        if(size>=500&&size < 1000)
        {
            time = r1();
        }
        else if(size>=1000&&size < 1500)
        {
            time = r2();
        }
        else if(size>=1500&&size < 2000)
        {
            time = r3();
        }
        else if(size>=2000&&size < 2500)
        {
            time = r4();
        }
        else if(size>=2500&&size < 3000)
        {
            time = r5();
        }
        else if(size>=3000&&size < 3500)
        {
            time = r6();
        }
        else if(size>=3500&&size < 4000)
        {
            time = r7();
        }
        else if(size>=4000&&size < 4500)
        {
            time = r8();
        }
        else
        {
            time = r9();
        }
        
        return time;
        
    }
    
     string assignIO()
    {
        RandomSeq r1(1,5);
        int num = r1();
        string need="";
        
        if(num == 1)
        {
            need = "keyboard";
        }
        else if(num == 2)
        {
            need = "mouse";
        }
        else if(num == 3)
        {
            need = "Both"; // keyboard and mouse
        }
        else if(num == 4)
        {
            need ="file";
        }
        else
        {
            need = "nothing";
        }
        return need;
    }
    
    
     void setHeader()
    {
        RandomSeq r1(0,4);
        RandomSeq r2(0,3);
        RandomSeq r3(0,2);
        INT_ITER hIter = header.begin();
        header.insert(hIter,r1());
        header.insert(hIter+1,r2());
        header.insert(hIter+2,r3());
    }
    
     int getNumberOfFiles() {
        return numOfFiles ;
    }
    void test(){
        cout << "Testing JobCreationFactory\n";
    }
        
};
int main(){
    return 0;
}

//.hxx follows below:

#ifndef JobCreationFactory_hxx__
#define JobCreationFactory_hxx__
#include "HardDisk.hxx"
class JobCreationFactory {
public:
    //JobCreationFactory(){
    //}
    int getNumberOfJobs();
    void createFiles(HardDisk hd);
    void createJobs(HardDisk hd);
    int assignSize();
    int assignTime(int size);
    string assignIO();
    void setHeader();
    int getNumberOfFiles();
    void test();
};

#endif // JobCreationFactory_hxx_

Have you defined all mentioned methods in corresponding classes? — xappymah, Mar 30 '11 at 03:10

score 1 · Answer 1 · answered Mar 30 '11 at 03:09

1

Compiling individually is a reasonable test for syntax errors, but there's no point in linking individually, things WILL be missing.

So find the compiler option to compile without linking (Microsoft Visual C++: /c, g++: -c) and use it.

answered Mar 30 '11 at 03:09

Ben Voigt

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I use g++ and i also used make by writing a CMakeLists.txt to tell make where to find files.Can someone look at the error : – user599319 Mar 30 '11 at 04:00

score 1 · Answer 2 · answered Mar 30 '11 at 04:15

1

This error is telling you that there's no definition for the method JobCreationFactory::createFiles -- so either you forgot to define that in any file anywhere, or the file defining it is not being linked along with osTester.cxx.o (which is the file that calls it).

answered Mar 30 '11 at 04:15

Chris Dodd

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Thanks.I have JobCreationFactory::createFiles in cxx and prototype in .hxx. – user599319 Mar 30 '11 at 04:23
So you need to add the .o file generated from the .cxx file to the linker command line – Chris Dodd Mar 31 '11 at 23:19

C++ Linking error

Update:

2 Answers2

Linked