C++ virtual functions.Problem with vtable
- by adivasile
I'm doing a little project in C++ and I've come into some problems regarding virtual functions.
I have a base class with some virtual functions:
#ifndef COLLISIONSHAPE_H_
#define COLLISIONSHAPE_H_
namespace domino
{
class CollisionShape : public DominoItem
{
public:
// CONSTRUCTOR
//-------------------------------------------------
// SETTERS
//-------------------------------------------------
// GETTERS
//-------------------------------------------------
virtual void GetRadius() = 0;
virtual void GetPosition() = 0;
virtual void GetGrowth(CollisionShape* other) = 0;
virtual void GetSceneNode();
// OTHER
//-------------------------------------------------
virtual bool overlaps(CollisionShape* shape) = 0;
};
}
#endif /* COLLISIONSHAPE_H_ */
and a SphereShape class which extends CollisionShape and implements the methods above
/* SphereShape.h */
#ifndef SPHERESHAPE_H_
#define SPHERESHAPE_H_
#include "CollisionShape.h"
namespace domino
{
class SphereShape : public CollisionShape
{
public:
// CONSTRUCTOR
//-------------------------------------------------
SphereShape();
SphereShape(CollisionShape* shape1, CollisionShape* shape2);
// DESTRUCTOR
//-------------------------------------------------
~SphereShape();
// SETTERS
//-------------------------------------------------
void SetPosition();
void SetRadius();
// GETTERS
//-------------------------------------------------
cl_float GetRadius();
cl_float3 GetPosition();
SceneNode* GetSceneNode();
cl_float GetGrowth(CollisionShape* other);
// OTHER
//-------------------------------------------------
bool overlaps(CollisionShape* shape);
};
}
#endif /* SPHERESHAPE_H_ */
and the .cpp file:
/*SphereShape.cpp*/
#include "SphereShape.h"
#define max(a,b) (a>b?a:b)
namespace domino
{
// CONSTRUCTOR
//-------------------------------------------------
SphereShape::SphereShape(CollisionShape* shape1, CollisionShape* shape2)
{
}
// DESTRUCTOR
//-------------------------------------------------
SphereShape::~SphereShape()
{
}
// SETTERS
//-------------------------------------------------
void SphereShape::SetPosition()
{
}
void SphereShape::SetRadius()
{
}
// GETTERS
//-------------------------------------------------
void SphereShape::GetRadius()
{
}
void SphereShape::GetPosition()
{
}
void SphereShape::GetSceneNode()
{
}
void SphereShape::GetGrowth(CollisionShape* other)
{
}
// OTHER
//-------------------------------------------------
bool SphereShape::overlaps(CollisionShape* shape)
{
return true;
}
}
These classes, along some other get compiled into a shared library.
Building libdomino.so
g++ -m32 -lpthread -ldl -L/usr/X11R6/lib -lglut -lGLU -lGL -shared -lSDKUtil -lglut -lGLEW -lOpenCL -L/home/adrian/AMD-APP-SDK-v2.4-lnx32/lib/x86 -L/home/adrian/AMD-APP-SDK-v2.4-lnx32/TempSDKUtil/lib/x86 -L"/home/adrian/AMD-APP-SDK-v2.4-lnx32/lib/x86" -lSDKUtil -lglut -lGLEW -lOpenCL -o build/debug/x86/libdomino.so build/debug/x86//Material.o build/debug/x86//Body.o build/debug/x86//SphereShape.o build/debug/x86//World.o build/debug/x86//Engine.o build/debug/x86//BVHNode.o
When I compile the code that uses this library I get the following error:
../../../lib/x86//libdomino.so: undefined reference to `vtable for domino::CollisionShape'
../../../lib/x86//libdomino.so: undefined reference to `typeinfo for domino::CollisionShape'
Command used to compile the demo that uses the library:
g++ -o build/debug/x86/startdemo build/debug/x86//CMesh.o build/debug/x86//CSceneNode.o build/debug/x86//OFF.o build/debug/x86//Light.o build/debug/x86//main.o build/debug/x86//Camera.o -m32 -lpthread -ldl -L/usr/X11R6/lib -lglut -lGLU -lGL -lSDKUtil -lglut -lGLEW -ldomino -lSDKUtil -lOpenCL -L/home/adrian/AMD-APP-SDK-v2.4-lnx32/lib/x86 -L/home/adrian/AMD-APP-SDK-v2.4-lnx32/TempSDKUtil/lib/x86 -L../../../lib/x86/ -L"/home/adrian/AMD-APP-SDK-v2.4-lnx32/lib/x86"
(the -ldomino flag)
And when I run the demo, I manually tell it about the library:
LD_LIBRARY_PATH=../../lib/x86/:$AMDAPPSDKROOT/lib/x86:$LD_LIBRARY_PATH bin/x86/startdemo
After reading a bit about virtual functions and virtual tables I understood that virtual tables are handled by the compiler and I shouldn't worry about it, so I'm a little bit confused on how to handle this issue.
I'm using gcc version 4.6.0 20110530 (Red Hat 4.6.0-9) (GCC)
Later edit:
I'm really sorry, but I wrote the code by hand directly here.
I have defined the return types in the code.
I apologize to the 2 people that answered below.
I have to mention that I am a beginner at using more complex project layouts in C++.By this I mean more complex makefiles, shared libraries, stuff like that.
