LI71616: SAME OBJECT CREATES DIFFERENT MANGLED NAME

Latest updates for XL C/C++ Advanced Edition V7 for Linux

APAR status

• Closed as program error.

Error description

• When rebuilding a shared object, its mangled name is not the
  same as it was when it was first built.  This makes it necessary
  to
  re-link an application everytime a shared object is rebuilt.
  

Local fix

• N/A
  

Problem summary

• same as submitter's text
  

Problem conclusion

• SER AFFECTED:
  User of local class with member functions, whom exported the
  symbol name in a shared library.
  
  PROBLEMDESCRIPTION:
  The mangled name of the member function of a local class changes
  between compliation, this make the shared library's interface
  unstable.
  
  WORKAROUND:
  Use import/export list to control what symbols are exported from
  shared library, and make sure member functions of a local class
  is not exported.  They shouldn't be part of the interface to a
  shared library anyway, since they can't be accessed (from a
  language point of view) outside of the function that declares
  it.
  
  EXPECTED ERROR:
  $ dump -tvX64 pre_a.o | grep "Clear"
  [58]    m
  0x000036e4     .text     1  extern
  .Clear__L304145d0c178_10StmtHandleFv
  
  [310]   m
  0x00006d80     .data     1  extern
  Clear__L304145d0c178_10StmtHandleFv
  
  when dumping object with exported local symbols, the symbols
  shows up as "extern" and the symbol is mangled in the form of
  *_L[0-9a-z]_*
  
  PROBLEM CONCLUSION:
  We changed the compiler to makr member functions in local class
  as static in, such that they don't get exported in shared
  library.
  

Temporary fix

• use an import/export list
  

Comments

APAR Information

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

  IY81246

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

Fix information

• Fixed component name

  XL C/C++ RHEL3

• Fixed component ID

  5724K7710

Applicable component levels

• R700 PSN IY81246

     UP06/09/13