Re: seg fault on startup

[David Daney <ddaney at avtrex dot com>]

Ben Tatham wrote:
> David Daney wrote:
> > Andrew Haley wrote:
> > > Ben Tatham writes:
> > >  > More fuel for the investigation.
> > >  >  > I have now tried to build our application with 
> > > GCC-4.2-20070307, with  > the much simpler -static-libgcj option...
> > >  >  > %.o : %.jar
> > >  >         $(gccdir)/bin/$(platform)-gcj $(includes) -c -g -O $<
> > >  >  > apollo : $(objects)
> > >  >         $(gccdir)/bin/$(platform)-gcj -g -O -static-libgcj -o  > 
> > > apollo.debug --main=ca.nanometrics.apollo.taurus.MissionControlTaurus 
> > >  > $(objects)
> > >  >         $(gccdir)/bin/$(platform)-strip --strip-debug apollo.debug 
> > > -o apollo
> > >  >  > Unfortunately, it still seg faults right at startup.  This 
> > > time, I get a  > backtrace though. Ah, excellent.
> > >
> > >  > Does this mean anything to anyone?  Why does it say that the
> > >  > language is c++ now though?
> > >
> > > Because it is.
> > >
> > >  > Program terminated with signal 11, Segmentation fault.
> > >  > #0  _Jv_RegisterClasses (classes=0x10f80074)
> > >  >     at  > 
> > > /disk1/xtool/crosstool-0.43/build/powerpc-860-linux-gnu/gcc-4.2-20070307-glibc-2.3.3/gcc-4.2-20070307/libjava/java/lang/natClassLoader.cc:189 
> > >
> > >  > 189     _Jv_RegisterClasses (const jclass *classes)
> > >
> > > classes is a pointer to an array of pointers, terminated by NULL.
> > > Every one of those pointers should pointo t a valid class structure
> > > inside your app.  Print them out.
> >
> > As an aside, I think there were bugs in some part of the mipsel-linux 
> > toolchain (I forget exactly where, but it was either the linker or 
> > glibc) that caused problems like this for me.  I think you are on the 
> > right track here.  It may be useful to compile libgcj with -O0 -g 
> > (edit the Makefile to change -O2 to -O0 and make clean; make).
> >
> > David Daney
>
> We'll give those changes a try, but I'm curious as the exact problems 
> you had, David.  You said "caused problems like this for me".  How 
> similar were they?

You get a SIGSEGV, I got a SIGSEGV, so I would say the problems were 
identical from the point of view of symptoms.  But I fixed the problems 
I had, and you still suffer from SIGSEGV, so from that point of view 
they are not the same problem.

I know that is not at all helpful.  You will have to run it in the 
debugger and see what is happening.  Unfortunately I know of no short cuts.

David Daney