LI77639: INCORRECT OUTPUT WITH DYNAMIC_CAST

XL C/C++ Runtime for Linux Fix Pack 7 (May 2014 Update) for 12.1
XL C/C++ for Linux Fix Pack 8 (October 2015 Update) for 12.1
XL C/C++ Runtime for Linux Fix Pack 8 (October 2015 Update) for 12.1
XL C/C++ for Linux Fix Pack 4 (October 2013 Update) for 12.1
XL C/C++ Runtime for Linux Fix Pack 4 (October 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 5 (December 2013 Update) for 12.1
XL C/C++ Runtime for Linux Fix Pack 5 (December 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 6 (February 2014 Update) for 12.1
XL C/C++ Runtime for Linux Fix Pack 6 (February 2014 Update) for 12.1
XL C/C++ for Linux Fix Pack 7 (May 2014 Update) for 12.1

APAR status

• Closed as program error.

Error description

• When compiling the following test case that makes use of
  dynamic_cast, the compiler does not generate correct code
  leading to incorrect output at runtime.
  
  ====Compile Command:
  $ xlC -qrtti=all test.cpp
  
  
  ====Testcase:
  $ cat test.cpp
  #include <demangle.h>
  #include <stdio.h>
  int main(int argc, char *argv[])
  {
      char* rest = 0;
      char *text_mangled =
          (argc > 1) ? argv[1] : ".funcGlobalOne__Fi";
      printf("text_mangled=\"%s\"\n", text_mangled);
      Name *name = Demangle(text_mangled, rest);
      printf("name=%x\n", name);
      printf("name->Kind()=%d\n", name->Kind());
      char *text_demangled=name->Text();
      printf("text_demangled=\"%s\"\n", text_demangled);
      void *dc = dynamic_cast<void *>(name);
      printf("dynamic_cast<void *>(name)=%x\n", dc); // This
  should not be 0
      return 0;
  }
  $
  
  
  =====Actual Output:
  $ ./a.out
  text_mangled=".funcGlobalOne__Fi"
  name=201be8f8
  name->Kind()=2
  text_demangled=".funcGlobalOne(int)"
  dynamic_cast<void *>(name)=0
  $
  
  
  =====Expected Output:
  $ ./a.out
  text_mangled=".funcGlobalOne__Fi"
  name=20002a30
  name->Kind()=2
  text_demangled=".funcGlobalOne(int)"
  dynamic_cast<void *>(name)=20002a30
  $
  

Local fix

• N/A
  

Problem summary

• USERS AFFECTED:
  Users of the demangler library who wish to use dynamic_cast or
  typeid on polymorphic class objects produced by the demangler
  library are affected by this issue.
  
  PROBLEM DESCRIPTION:
  RTTI information is not present for class objects produced by
  demangler library.
  

Problem conclusion

• The version of the demangler library which is integrated with
  the C++ shared library runtime is now built with support for
  dynamic_cast and typeid.
  The stand-alone version is not updated and should not be used
  with C++ applications without careful isolation measures.
  

Temporary fix

Comments

APAR Information

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

  IV46715

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

Fix information

• Fixed component name

  XL C/C++ FOR LI

• Fixed component ID

  5725C7300

Applicable component levels

• RC10 PSN IV46715

     UP06/09/13