CODEWITHSUNDEEP
c++g++
user2406944
user2406944

Reputation:

G++ Undefined symbols for architecture x86_64

I am learning C++ and have been given an assignment to create a Vector3D class. When I try to compile main.cpp using G++ on OSX I get the following error message. Why would this be?

g++ main.cpp 
Undefined symbols for architecture x86_64:
  "Vector3DStack::Vector3DStack(double, double, double)", referenced from:
      _main in cc9dsPbh.o
ld: symbol(s) not found for architecture x86_64

main.cpp

#include <iostream>;
#include "Vector3DStack.h";

using namespace std;

int main() {
    double x, y, z;
    x = 1.0, y = 2.0, z = 3.0;
    Vector3DStack v (x, y, z);
    return 0;
}

Vector3DStack.h

class Vector3DStack {
public:
    Vector3DStack (double, double, double);

    double getX ();
    double getY ();
    double getZ ();

    double getMagnitude();

protected:
    double x, y, z;
};

Vector3DStack.cpp

#include <math.h>;
#include "Vector3DStack.h";

Vector3DStack::Vector3DStack (double a, double b, double c) {
    x = a;
    y = b;
    z = c;
}

double Vector3DStack::getX () {
    return x;
}

double Vector3DStack::getY () {
    return y;
}

double Vector3DStack::getZ () {
    return z;
}

double Vector3DStack::getMangitude () {
    return sqrt (pow (x, 2) * pow (y, 2) * pow (z, 2));
}

Upvotes: 8

Views: 21758

Answers (3)

ak_2050
ak_2050

Reputation: 159

I had ran into a similar issue when writing my own implementation of a hashTable with templates. In your main.cpp, just include "Vector3DStack.cpp", which includes Vector3DStack.h, instead of just including Vector3DStack.h.

In my case, since templates, as we know, are evaluated at compile time, having templatized (including fully specialized) methods in the class as part of the cpp file (where they are defined) need to be known to the compiler. Some of the C++ gotchas.. so much to remember, easy to forget the little things.

Mostly likely you've already got our solution, thanks to the answers posted earlier, but my $0.02 anyways.

Happy C++ Programming!

Upvotes: 4

piokuc
piokuc

Reputation: 26204

Pass the implementation of Vector3D to the compiler:

g++ main.cpp Vector3DStack.cpp

This will produce executable called a.out on Linux and Unix systems. To change the executable name use -o option:

g++ -o my_program main.cpp Vector3DStack.cpp

This is the simplest possible way of building your program. You should learn a bit more - read about make program, or even cmake.

Upvotes: 7

Fozi
Fozi

Reputation: 5145

You have to compile and link your Vector3DStack.cpp as well. Try:

g++ main.cpp Vector3DStack.cpp -o vectortest

This should create an executable called vectortest.

Upvotes: 24

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