IV72776: TEMPLATE FUNCTION NOT ABLE TO PARSE CHARACTER PROPERLY

XL C/C++ for AIX Fix Pack 3 (April 2015 PTF) for 13.1
XL C/C++ for AIX Fix Pack 4 (July 2015 PTF) for 13.1
XL C/C++ for AIX Fix Pack 5 (November 2015 PTF) for 13.1
XL C/C++ for AIX Fix Pack 6 (February 2016 PTF) for 13.1
XL C/C++ for AIX Fix Pack 7 (May 2016 PTF) for 13.1
XL C/C++ for AIX Fix Pack 8 (August 2016 PTF) for 13.1
XL C/C++ for AIX Fix Pack 9 (June 2017 PTF) for 13.1
XL C/C++ for AIX Fix Pack 10 (February 2018 PTF) for 13.1
XL C/C++ for AIX Fix Pack 11 (November 2018 PTF) for 13.1

APAR status

• Closed as program error.

Error description

• A template function is not instantiated, and an incorrect
  template function is called when multiple template
  instantiations with the same function names with the same
  argument types exist.
  
  
  
     === TEST CASE ===
  
  extern "C" printf(const char*, ...);
  
  typedef const char (*templatetype)(const char);
  
  template <char pre>
  const char test(const char src )
  {
   if ( src != pre)
    {
    printf(" error src must be equal to pre\n");
   }
   return src == pre ? src  : 0;
  }
  
  class myClass
  {
   public:
      template <templatetype mx>
    const char check(const char start )
      {
        const char c = mx(start);
        if (c) return c;
        else return 0;
      }
  };
  
  int main()
  {
    myClass f;
    f.check < test<';'> >(';');
    f.check < test<'.'> >('.');
  }
  
  
  
  $ xlC test.cpp
  $ ./a.out
   error src must be equal to pre
  $
  

Local fix

Problem summary

• USERS AFFECTED:
  Users with code that requires multiple template instantiations
  with same function names with same argument types are affected
  by this issue.
  
  PROBLEM DESCRIPTION:
  Template instantiation cache was selecting the cached
  candidate, looking at the arguments and assuming that the
  candidate is exact match.
  

Problem conclusion

• The fix has been made so that the template instantiation cache
  is not used in case where function name and argument types are
  the same.
  This ensures that two separate instantiations happen when there
  is an ambiguity for the compiler.
  

Temporary fix

Comments

APAR Information

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

  IV68555

• 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

• RD10 PSY