IJ13078: SIGNAL 11 AT RUNTIME WITH INLINE VIRTUAL FUNCTION CALL VIA TOC ENTRY WITH QMINIMALTOC

XL C/C++ for AIX, V16.1.0.2 Fix Pack (March 2019)

APAR status

• Closed as program error.

Error description

• An application encounters a runtime signal 11 when calling an
  inline class method/function that uses a non-virtual thunk
  (function descriptor stored in the TOC).  Moving the method out
  of the class to be non-inline avoids the problem.  The inline
  method could look like:
  
  ================================================================
  class A : public B
  {
     ...
     virtual void mymethod() {}
  ================================================================
  
  When the application runs, the signal 11 gives a stack
  trace that ends in:
  
  ================================================================
  non-virtual thunk to A::mymethod() at 0x900000000bec8b0
  ...
  ================================================================
  
  The issue occurs when compiling with the -qminimaltoc option.
  

Local fix

• Do not use -qminimaltoc
  

Problem summary

• PROBLEM DESCRIPTION:
  The offset generated by the compiler for loading the thunk
  address from the TOC is not properly tagged as minimal toc,
  therefore the value is incorrect and a signal 11 occurs.
  
  USERS AFFECTED:
  Users of virtual functions with -qminimaltoc
  

Problem conclusion

• The offset genreation was corrected.
  

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

• RG10 PSY

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