c++/9377: g++ 64bit calls wrong function -> Multi-inheritance: pointer to member function of the 2nd base calss points to wrong place

[Wolfgang Bangerth]

The following reply was made to PR c++/9377; it has been noted by GNATS.

From: Wolfgang Bangerth <bangerth@ticam.utexas.edu>
To: Andrew Xiong <axiong@ca.ibm.com>
Cc: gcc-bugs@gcc.gnu.org, <gcc-gnats@gcc.gnu.org>
Subject: Re: c++/9377: g++ 64bit calls wrong function -> Multi-inheritance:
 pointer to member function of the 2nd base calss points to wrong place
Date: Tue, 21 Jan 2003 11:30:30 -0600 (CST)

 > Actually, with the C++ compiler (xlC) on AIX, for both 32-bit and 64-bit
 > compiling,  we can do:
 >    PMF aPMF = (char *(D::*)()) &B2::bar ;
 > And also,  with g++ for 32-bit compiling, we can do:
 >    PMF aPMF = (char *(D::*)()) &B2::bar ;
 > 
 > The problem is only for g++ 64-bit compiling: we can not do it only for g++
 > 64-bit compiling.
 
 The fact that it works with one compiler and not with the other is of 
 course no proof of either one being right :-) What I meant is that the 
 question 32 vs 64 bit affects the layout of the virtual function table, so 
 I wouldn't be surprised if an accidentially working program breaks when 
 you change something like the layout of the vt.
 
 That being said, I reopened the report to let others have a second look on 
 things.
 
 Regards
   Wolfgang
 
 -------------------------------------------------------------------------
 Wolfgang Bangerth             email:            bangerth@ticam.utexas.edu
                               www: http://www.ticam.utexas.edu/~bangerth/