RE: Problem with gcj cross from i686-linux to arm-linux.

["Boehm, Hans" <hans dot boehm at hp dot com>]

If you suspect the GC, it would also be good to know whether gctest
(tests/test.c in the GC directory) runs successfully.  If not, that may
be easier to debug.

Hans 

> -----Original Message-----
> From: java-owner@gcc.gnu.org [mailto:java-owner@gcc.gnu.org] 
> On Behalf Of David Daney
> Sent: Monday, June 19, 2006 2:45 PM
> To: hartzell@alerce.com
> Cc: java@gcc.gnu.org
> Subject: Re: Problem with gcj cross from i686-linux to arm-linux.
> 
> George Hartzell wrote:
> > I'm using the openembedded build tools 
> (www.openembedded.org) to build 
> > a system for a Zaurus SL-6000L [aka a "tosa"].  I'm using a recent 
> > update of the org.openembedded.dev tree (openembedded uses monotone 
> > for revision control).  I edited the 
> packages/gcc/gcc3-build.inc file 
> > and added ",java" to the JAVA_arm variable so that it would 
> build gcj, 
> > and in my local.conf file I set:
> > 
> >    PREFERRED_VERSION_gcc = "4.1.1"
> >    PREFERRED_VERSION_gcc-cross = "4.1.1"
> >    PREFERRED_VERSION_gcc-cross-initial = "4.1.1"
> > 
> > so that it would use gcc4.1.1.  I'm running a 2.6 kernel on the 
> > SL-6000L, which is still considered a work in progress.
> > 
> > I can compile and link a simple Hello world program as follows:
> > 
> >   gcc -c Hello.java
> >   gcc --main=Hello -o Hello Hello.o
> > 
> > Then move the resulting executable and libgcj.so.7 over to 
> the Zaurus 
> > and set LD_LIBRARY_PATH=. so that it can find libgcj.
> > 
> > It blows up the first several times that I try to run it but 
> > eventually runs successfully.
> > 
> > This time around (after rebooting) it said:
> > 
> >   Aborted
> > 
> > then the second time:
> > 
> >   Illegal Instruction
> > 
> > then the third run:
> > 
> >    Exception during runtime initialization
> >    java.lang.ExceptionInInitializerError
> >       <<No stacktrace available>>
> >    Caused by java.lang.NullPointerException
> >       <<No stacktrace available>>
> > 
> > and finally
> > 
> >    Hello there.
> > 
> > Once it's run successfully then it seems to continue to run 
> correctly.  
> > I've also seen it crash with a "Segmentation fault".
> > 
> > I've seen posts describing two arm related problems in the boehm-gc 
> > library, one that changes how it finds the bottom of the stack from 
> > "HEURISTIC1" to "LINUX_STACKBOTTOM" and one that makes a 
> small change 
> > to the test-and-set function.  Both changes seem to be in the gcc
> > 4.1.1 tree that I'm using.
> > 
> > The system is using "glibc-2.3.5+cvs20050627-r7" and 
> > "binutils-cross-2.16-r7".
> > 
> > I originally tried using gcc-3.4.4 and had the same problems (even 
> > after confirming/adding the two fixed described above).
> > 
> > Does the behaviour I'm describing above sound familiar to anyone?
> > 
> > What extra information can I provide to help figure out 
> what's going 
> > wrong?
> > 
> 
> I think it likely that nobody is using gcj on arm-linux-*, or 
> if they are any patches they are using have not been merged 
> back to GCC.
> 
> Unfortunatly this probably means that you will have to run it 
> under gdb and try to figure out what is happening.  Once you 
> have more specific information, we may be able to guide you.
> 
> David Daney.
>