Undefined reference to vtable

Question

So, I'm getting the infamously horrible "undefined reference to 'vtable..." error for the following code (The class in question is CGameModule.) and I cannot for the life of me understand what the problem is. At first, I thought it was related to forgetting to give a virtual function a body, but as far as I understand, everything is all here. The inheritance chain is a little long, but here is the related source code. I'm not sure what other information I should provide.

Note: The constructor is where this error is happening, it'd seem.

My code:

class CGameModule : public CDasherModule {
 public:
  CGameModule(Dasher::CEventHandler *pEventHandler, CSettingsStore *pSettingsStore, CDasherInterfaceBase *pInterface, ModuleID_t iID, const char *szName)
  : CDasherModule(pEventHandler, pSettingsStore, iID, 0, szName)
  { 
      g_pLogger->Log("Inside game module constructor");   
      m_pInterface = pInterface; 
  }

  virtual ~CGameModule() {};

  std::string GetTypedTarget();

  std::string GetUntypedTarget();

  bool DecorateView(CDasherView *pView) {
      //g_pLogger->Log("Decorating the view");
      return false;
  }

  void SetDasherModel(CDasherModel *pModel) { m_pModel = pModel; }


  virtual void HandleEvent(Dasher::CEvent *pEvent); 

 private:



  CDasherNode *pLastTypedNode;


  CDasherNode *pNextTargetNode;


  std::string m_sTargetString;


  size_t m_stCurrentStringPos;


  CDasherModel *m_pModel;


  CDasherInterfaceBase *m_pInterface;
};

Inherits from...

class CDasherModule;
typedef std::vector<CDasherModule*>::size_type ModuleID_t;

/// \ingroup Core
/// @{
class CDasherModule : public Dasher::CDasherComponent {
 public:
  CDasherModule(Dasher::CEventHandler * pEventHandler, CSettingsStore * pSettingsStore, ModuleID_t iID, int iType, const char *szName);

  virtual ModuleID_t GetID();
  virtual void SetID(ModuleID_t);
  virtual int GetType();
  virtual const char *GetName();

  virtual bool GetSettings(SModuleSettings **pSettings, int *iCount) {
    return false;
  };

 private:
  ModuleID_t m_iID;
  int m_iType;
  const char *m_szName;
};

Which inherits from....

namespace Dasher {
  class CEvent;
  class CEventHandler;
  class CDasherComponent;
};

/// \ingroup Core
/// @{
class Dasher::CDasherComponent {
 public:
  CDasherComponent(Dasher::CEventHandler* pEventHandler, CSettingsStore* pSettingsStore);
  virtual ~CDasherComponent();

  void InsertEvent(Dasher::CEvent * pEvent);
  virtual void HandleEvent(Dasher::CEvent * pEvent) {};

  bool GetBoolParameter(int iParameter) const;
  void SetBoolParameter(int iParameter, bool bValue) const;

  long GetLongParameter(int iParameter) const;
  void SetLongParameter(int iParameter, long lValue) const;

  std::string GetStringParameter(int iParameter) const;
  void        SetStringParameter(int iParameter, const std::string & sValue) const;

  ParameterType   GetParameterType(int iParameter) const;
  std::string     GetParameterName(int iParameter) const;

 protected:
  Dasher::CEventHandler *m_pEventHandler;
  CSettingsStore *m_pSettingsStore;
};
/// @}


#endif

Answer 1

• Are you sure that CDasherComponent has a body for the destructor? It's definitely not here - the question is if it is in the .cc file.
• From a style perspective, CDasherModule should explicitly define its destructor virtual.
• It looks like CGameModule has an extra } at the end (after the }; // for the class).
• Is CGameModule being linked against the libraries that define CDasherModule and CDasherComponent?

Answer 2

The GCC FAQ has an entry on it:

The solution is to ensure that all virtual methods that are not pure are defined. Note that a destructor must be defined even if it is declared pure-virtual [class.dtor]/7.

Answer 3

So, I've figured out the issue and it was a combination of bad logic and not being totally familiar with the automake/autotools world. I was adding the correct files to my Makefile.am template, but I wasn't sure which step in our build process actually created the makefile itself. So, I was compiling with an old makefile that had no idea about my new files whatsoever.

Thanks for the responses and the link to the GCC FAQ. I will be sure to read that to avoid this problem occurring for a real reason.