Re: Segfaults with Redhat 6.0; gdb crashes too

[Paul Johnson]

The warnings you see are due to a flaw in the code for egcs.  If you get
the patch for egcs that Marcus put in this list about a month ago, you
can compile a new egcs and then use it to build swarm and the warnings
disappear. Alternatively, you can get the newest set of RPMS for Swarm
from my site and those are compiled with the enhanced egcs and you
should not see the warnings.

As for the segfaults, there are some questions I would ask.  1) is you
system a "clean RH install" or an upgrade?

2) Is swarm compiled with the same version of egcs you are using to
compile the applications? It ought to be.



Concerning the gdb questions, I'd like to remind you that the gdb redhat
distributed 6.0 is flawed.  You can either run a newer edition of gdb
you compile yourself (Marcus posted that address last week) or
"downgrade" to the gdb that is on the sfi web site.  The one on the sfi
web site has the objective C patches applied, so I find it very much
preferrable.  Just untar it and put it over the binary file gdb on your
system.  If you do "gdb program" and then after running to a seg fault,
you should type "bt" and it will show the steps leading up the core
dump. 

As far as the other gdb problem you mention, about the core file not
being recognized, I have two ideas.  Are you typing "gdb programname
core" as you ought to?  If you use a gdb that does not suck, it will
work.


Erik Rauch wrote:
> 
> I am running redhat 6.0 with egcs 1.1.2-12 and egcs-objc 1.1.2-12
> (egcs version 2.91.66). All applications compile but immediately
> segfault. Compilation of the apps in swarmapps-1.4 is successful but
> gives the following warnings:
> 
> >/usr/bin/ld: warning: type and size of dynamic symbol
> >`__objc_class_name_SwarmObject' are not defined
> >/usr/bin/ld: warning: type and size of dynamic symbol
> >`__objc_class_name_ZoomRaster' are not defined
> [...]
> >/usr/bin/ld: warning: type and size of dynamic symbol
> >`__objc_class_name_Diffuse2d' are not defined
> 
> >address@hidden heatbugs]$ ./heatbugs
> >Illegal instruction (core dumped)
> 
> I am asking for help because I have no information to go on; gdb
> itself segfaults when I try to use it to find the error:
> 
> >address@hidden heatbugs]$ gdb heatbugs
> >GNU gdb 4.17.0.11 with Linux support
> >Copyright 1998 Free Software Foundation, Inc.
> >GDB is free software, covered by the GNU General Public License, and
> >you are welcome to change it and/or distribute copies of it under
> >certain conditions.  Type "show copying" to see the conditions.
> >There is absolutely no warranty for GDB.  Type "show warranty" for
> >details.  This GDB was configured as "i386-redhat-linux"...
> >(gdb) run
> >Starting program: /home/rauch/swarm/swarmapps-1.4/heatbugs/heatbugs
> >Segmentation fault (core dumped)
> >address@hidden heatbugs]$
> 
> It also refuses to look at the resulting core dump:
> 
> >"/home/rauch/swarm/ant/core": not in executable format: File format
> >not recognized
> 
> My $SWARMHOME and $DISPLAY variables are properly set.
> 
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-- 
Paul E. Johnson                       email: address@hidden
Dept. of Political Science            http://lark.cc.ukans.edu/~pauljohn
University of Kansas                  Office: (785) 864-9086
Lawrence, Kansas 66045                FAX: (785) 864-5700

                  ==================================
   Swarm-Support is for discussion of the technical details of the day
   to day usage of Swarm.  For list administration needs (esp.
   [un]subscribing), please send a message to <address@hidden>
   with "help" in the body of the message.