IJ45426: APPLICATIONS BUILT WITH XL C/C++ FOR AIX, V16.1 USING IPA/PDF MAY SEGFAULT WHEN RUN WITH C++ RUNTIME FOR AIX, V17.1.1.1 PTF

APAR status

• Closed as program error.

Error description

• An application compiled with XL C/C++ for AIX, V16.1 using
  IPA/PDF when run on the C++ Runtime for AIX, V17.1.1.1 PTF
  may lead to a coredump.
  
  This APAR is being used to mark the previous XL C/C++ for AIX,
  V17.1.1.1 PTF as a PE PTF.
  

Local fix

• N/a
  

Problem summary

• USERS AFFECTED:
  Users whose applications are built by XLC/C++ V16.1 for AIX
  xlclang++ compiler and running against the XL Open V17.1.1.1 C++
  runtime and make use of C++ exception handling,
  and either specify '#pragma execution_frequency' in conjunction
  with an optimization option or are compiled with -qpdf2 in
  conjunction with an optimization option may be affected by this
  issue.
  
  PROBLEM DESCRIPTION:
  The V17.1.1.1 C++ runtime's personality routine for V16.1
  xlclang++ compiler generated applications uses the stack to pass
  the exception object to the landing pad.
  The landing pad retrieves the exception object with a call to
  the runtime function __xlc_exception_handle(). The
  implementation incorrectly assumes that __xlc_exception_handle()
  should go up one stack frame to get to the stack frame of the
  caller of __xlc_exception_handle(), which is supposedly the
  stack frame of the function containing the landing pad.
  However, this does not always work, e.g., the xlclang++ compiler
  generates a wrapper of __xlc_exception_handle() and calls the
  wrapper from the landing pad for optimization purposes.
  

Problem conclusion

• This problem is pervasive and should be fixed. This APAR is
  being used to mark the previous V17.1.1.1 PTF as a PE PTF.
  Since this is a problem in the XL Open V17.1.1 C++ runtime that
  affects the binary compatibility with XLC/C++ V16.1 compiled
  applications,
  the fix is in the XL Open V17.1.1 C++ runtime not in XLC/C++
  V16.1 compiler or runtime.
  

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