Re: SEGV building qt-3.3.3 with GCC 3.4.3 on RH 7.1/RHEL 2.1

[Michael Matz <matz@suse.de>]

Hi,

On Thu, 2 Dec 2004, Joe Buck wrote:

> On Thu, Dec 02, 2004 at 04:33:02PM -0600, Albert Chin wrote:
> > Just build Qt-3.3.3 with GCC 3.4.2 and 3.4.3 on Redhat Linux 7.1/x86
> > and RHEL 2.1/x86. No problems with 3.4.2. However, when building with
> > 3.4.3, I get a segfault during the build:
> >   ...
> > Redhat Linux 9/x86, RHEL 3.0/x86, and RHEL 3.0/amd64 work fine. I
> > reviewed http://gcc.gnu.org/gcc-3.4/changes.html#3.4.3 but nothing
> > stands out as to what causes this. Where should I start looking?
> 
> Are you saying that you get a segfault when you build with 3.4.3 on RHEL
> 2.1, but not when you build with 3.4.3 on RHEL 3.0 or RH9?  If so, this
> doesn't sound like the compiler is at fault.  A KDE developers' list might
> be a better place to track this one down, but I don't see any alternative
> to just debugging the problem.  If the blowup is in a place where there
> appears to be no code, it's probably in a destructor.

It might be similar to problems we faced when building KDE with HEAD.  
The problem there was the mt allocator which accessed static objects in
it's dtors, which already were deleted (the order of dtor running is not
specified).  This results in erratic behaviour, and it's possible that it
doesn't lead to segfaults in some circumstances.  You should be able to
investigate this with valgrind.  The difference with the different version
might have to do with different default configurations chosen by GCC
depending on the system it's build on.  And of course, it still is
possibly a KDE bug, so after valgrinding it report it there too.


Ciao,
Michael.