IZ91500: TEMPLATE INSTANTIATION PROBLEM with sizeof

January 2011 PTF for XL C/C++ for AIX, V11.1
May 2011 PTF for XL C/C++ for AIX, V11.1
August 2011 PTF for XL C/C++ for AIX, V11.1
November 2011 PTF for XL C/C++ for AIX, V11.1
January 2012 PTF for XL C/C++ for AIX, V11.1
April 2012 PTF for XL C/C++ for AIX, V11.1
July 2012 PTF for XL C/C++ for AIX, V11.1
October 2012 PTF for XL C/C++ for AIX, V11.1
February 2013 PTF for XL C/C++ for AIX, V11.1
XL C/C++ for AIX Fix Pack 14 (May 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 15 (August 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 16 (November 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 17 (February 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 18 (May 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 19 (August 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 20 (November 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 21 (April 2015 PTF) for 11.1
XL C/C++ for AIX Fix Pack 22 (September 2015 PTF) for 11.1
XL C/C++ for AIX Fix Pack 23 (March 2016 PTF) for 11.1
XL C/C++ for AIX Fix Pack 24 (September 2016 PTF) for 11.1

APAR status

• Closed as program error.

Error description

• The following test case fails on AIX with xlC
  with the error:
  
  "overloadresolutionbug.cpp", line 25.45: 1540-0270 (S) An object
  of
  type "CtorLookupFailClass<int>" cannot be constructed from an
  lvalue of
  type "UniqueType * const".
  "overloadresolutionbug.cpp", line 25.3: 1540-0700 (I) The
  previous
  message was produced while processing
  "OverloadResolutionBugClass<int>::
  OverloadResolutionBugClass(UniqueType * const &)".
  "overloadresolutionbug.cpp", line 38.8: 1540-0700 (I) The
  previous
  message was produced while processing "struct C<UniqueType *
  const,
  OverloadResolutionBugClass<int> >".
  "overloadresolutionbug.cpp", line 52.5: 1540-0700 (I) The
  previous
  message was produced while processing "main()".
  
  
  
  ===== TESTCASE:
  $cat overloadresolutionbug.cpp.cpp
  
  template <typename TYPE>
  struct TypeClass {
      static TYPE& type();
  };
  
  class UninterestingType {
  };
  
  template <class T >
  class CtorLookupFailClass {
      public:
          CtorLookupFailClass();
          explicit CtorLookupFailClass(UninterestingType *);
  };
  
  template <unsigned int INT>
  struct SingleTemplateValueClass {
  enum { VALUE = (int) INT };
  };
  
  template <class T>
  class OverloadResolutionBugClass : public CtorLookupFailClass<T>
  {
  public:
    template <class U>
    OverloadResolutionBugClass (const U& v) :
  CtorLookupFailClass<T>(v) { }
  };
  
  struct UniqueType {
  } myTypeObj;
  
  struct B {
      static SingleTemplateValueClass<1> match(B&);
      template <typename T> static SingleTemplateValueClass<0>
  match(const T&);
      template <typename T> static SingleTemplateValueClass<0>
  match(const volatile T&);
  };
  
  template <typename FROM_TYPE, typename TO_TYPE >
  struct C {
  private:
    struct Test
    {
        B& operator, (TO_TYPE) const;
    };
  
  public:
    enum {
        VALUE = sizeof(B::match((TypeClass<Test>::type(),
  
  TypeClass<FROM_TYPE>::type())))
    };
  };
  
  int main () {
  
    const int a = C<struct UniqueType * const ,
  
  OverloadResolutionBugClass<int> >::VALUE;
  
    return 0;
  }
  

Local fix

• N/A
  

Problem summary

• PROBLEM DESCRIPTION: A template function is being instantiated
  in the operand of a sizeof, when sizeof operands are not to be
  evaluated
  
  USERS AFFECTED: the problem will only effect users who expect
  no template functions instantiated as part of the operand of a
  sizeof
  

Problem conclusion

• template functions will no longer be instantiated when
  processing the operand of sizeof
  

Temporary fix

Comments

APAR Information

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

  IZ80294

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

Fix information

• Fixed component name

  XL C/C++ AIX

• Fixed component ID

  5724X1300

Applicable component levels