LI76666: UNRESOLVED SYMBOL ERROR WITH -QIPA=LEVEL=0

XL C/C++ for Linux Fix Pack 9 (August 2013 Update) for 11.1
June 2012 Update for XL C/C++ for Linux, V11.1
October 2012 Update for XL C/C++ for Linux, V11.1
XL C/C++ for Linux Fix Pack 8 (June 2013 Update) for 11.1

APAR status

• Closed as program error.

Error description

• Clients who list duplicate libraries on their link line more
  than once and link with -qipa may observe unresolved symbol
  errors at link time.
  
  eg:
  $xlC_r -O2 -q64 -L. -o abc abc.o -la -lb -lc -lb -la
  -qipa=level=0 -qinline=noauto -qipa=relink
  .
  .
  d: 0711-317 ERROR: Undefined symbol:
  .A2i::Utf8::GraphemeReference::Compare(const
  A2i::Utf8::GraphemeReference&) const
  ld: 0711-317 ERROR: Undefined symbol:
  .A2i::Genrl::Msrmnt::operator==(const
  A2i::Genrl::Msrmnt::MeasurementInfo&,const
  A2i::Genrl::Msrmnt::MeasurementInfo&)
  ld: 0711-317 ERROR: Undefined symbol:
  .A2i::Protocol::BidirectionalBlockHeader::BidirectionalBlockHead
  er()
  $
  

Local fix

• As a workaround to avoid this problem, remove all the duplicate
  library entries from the link line.
  

Problem summary

• USERS AFFECTED:
  Users of TPO with -O4 and above may be affected by this issue.
  
  PROBLEM DESCRIPTION:
  The compiler tries to avoid putting archives which are
  completely IPA
  enabled on the linker command line because all the functions
  from them will now
  be in object files for partitions at the end of IPA link. If an
  archive has any non-IPA stuff it must be on the command line.
  So at the start of IPA link, we process all object files
  including archives.
  They go into a table. In the case for this APAR, there will be
  more than one entry in the table
  for the ones that are duplicated on the command line.
  Then as we read in the object files out of the libraries we
  flag entries
  in the table as to whether they are all IPA or have some
  non-IPA members.
  Then at link edit time right before we call the linker we
  bypass the ones
  that are IPA only. However the thing that flags them only looks
  down to the first entry for
  the containing library; and we bypass that one correctly.
  But the later entries are still in that table and they are not
  bypassed.
  They never had any flags set so they get added to the command
  line to the linker which causes
  the unresolved symbols at link time.
  

Problem conclusion

• The fix is to make a pass over the table and mark duplicate
  entries the same as the first one so the correct bypassing will
  work.
  

Temporary fix

Comments

APAR Information

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

  IV09519

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

Fix information

• Fixed component name

  XL C/C++ FOR LI

• Fixed component ID

  5724X1400

Applicable component levels

• RB10 PSN IV09519

     UP06/09/13