c++/3145: virtual inheritance still creates wrong code

[stefan@space.twc.de]

>Number:         3145
>Category:       c++
>Synopsis:       virtual inheritance still creates wrong code
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 12 14:46:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     stefan@space.twc.de
>Release:        gcc version 3.0 20010612 (prerelease)
>Organization:
>Environment:

>Description:
aRts still doesn't work with gcc3 (segfault on start). So
I thought instead of generating testcases one by one all
the time, which always opens the possibility that some
cases work but others break, I wrote a testcase generator
for the set of testcases that is just a complex (partially
virtual) inheritance graph and segfaults on execution.

I found that with the current gcc3 a good share of the
generated testcases segfaults when compiled and executed,
whereas with gcc-2.95.2, none of these sefaults.
>How-To-Repeat:
make tcgen
for i in $(seq 1 1000)
do
  tcgen $i > t.cc ; g++ 2>/dev/null -O2 t.cc ; a.out || echo $i failed
done
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
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