IJ21750: THE BASE CLASS IS DECLARED BUT NOT DEFINED ERROR

APAR status

• Closed as program error.

Error description

• The following test case triggers the error when compiled with
  xlC:
  
  ====COMPILE COMMAND:
  xlC_r test.cpp
  
  ====TESTCASE
  class ObjectManager;
  
  typedef ObjectManager& (*ObjectManagerFactory)();
  
  template<class Object>
  class DefaultObjectManagerFactory
  {
  public:
    static ObjectManager& Retrieve();
  
  };
  
  class BaseInternalCollection;
  
  class BaseCollection
  {
    BaseInternalCollection* m_letter;
  public:
  
    BaseCollection(int size, ObjectManagerFactory factory);
    void Copy(const BaseCollection& iSrc, ObjectManagerFactory
  factory);
    void Die(ObjectManagerFactory factory);
    void BuildFromTuple(BaseInternalCollection* t,
  ObjectManagerFactory factory);
  protected:
    BaseCollection();
  };
  
  template<typename T, ObjectManagerFactory M> class
  InternalCollection;
  
  template<typename T, ObjectManagerFactory M =
  DefaultObjectManagerFactory<T>::Re
  trieve  >
  class Collection : public BaseCollection
  {
  public:
    inline Collection() { }
    explicit inline Collection(int iSize) : BaseCollection(iSize,
  M) { }
    inline Collection(const Collection<T, M>& t) :
  BaseCollection(0, M) { BaseColl
  ection::Copy(t, M); }
    inline Collection<T, M>& operator=(const Collection<T, M>& t)
  { BaseCollection
  ::Copy(t, M); return *this; }
  
  
  
    inline void BuildFromTuple(InternalCollection<T, M>& iTuple) {
  BaseCollection:
  :BuildFromTuple((BaseInternalCollection*)&iTuple, M); }
  
    inline ~Collection() { Die(M); }
  };
  
  struct Item
  {
  };
  
  
  
  
  
  template<> ObjectManager&
  DefaultObjectManagerFactory<Item>::Retrieve();
  
  class Event
  {
    Collection<Item> m_postProcessingTasks; //first 'usage' of
  DefaultObjectManage
  rFactory<Item>::Retrieve
  };
  
  //'interface' ObjectManager
  class ObjectManager
  {
  public:
    const unsigned int m_width;
  
    inline ObjectManager(unsigned int width) : m_width(width) {}
  
    virtual void InitVect(void* dst, unsigned int count) const =
  0;
    virtual void InitVect(void* dst, const void* src, unsigned int
  count) const;
    virtual int Compare(const void* ptr1, const void* ptr2) const
  = 0;
  };
  
  struct NoCompareManager : public ObjectManager
  {
    NoCompareManager(unsigned int iSizeOf) :
  ObjectManager(iSizeOf) {}
    virtual void InitVect(void* to, unsigned sz)  const;
    virtual int Compare(const void* v1, const void * v2) const;
  };
  
  template<class T>
  struct BaseClassManager : public NoCompareManager
  {
    BaseClassManager() :NoCompareManager(sizeof(T)) {}
    virtual void InitVect(void *to, const void *from, unsigned sz)
  const
    {
    }
  };
  
  template<class T>
  struct ClassManager : public BaseClassManager<T> //COMPILATION
  ERROR HERE: (S) T
  he base class "BaseClassManager<Item>" is declared but not
  defined.
  {
    virtual void InitVect(void *to, unsigned sz)  const
    {
    }
  };
  
  template<>
  ObjectManager& DefaultObjectManagerFactory<Item>::Retrieve() //
  (I) The previous
  message was produced while processing
  "DefaultObjectManagerFactory<Item>::Retri
  eve()".
  {
    static ClassManager<Item> s_mgr; // (I) The previous message
  was produced whil
  e processing "struct ClassManager<Item>".
    return s_mgr;
  }
  $
  

Local fix

• N/A
  

Problem summary

• USERS AFFECTED:
  Users with explicit specializations
  referenced in certain contexts before the
  definition of the explicit specialization are affected by this
  issue.
  
  PROBLEM DESCRIPTION:
  The set of names and semantic properties that are reachable from
  the
  definition of the explicit specialization may be determined
  incorrectly.
  

Problem conclusion

• The treatment of the definition of explicit specializations has
  been made to be more consistent with that of non-template
  definitions.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  XL C/C++ FOR AI

• Fixed component ID

  5725C7200

Applicable component levels