RE: Dependencies when using gcc-generated object files in another compiler

["Lehner, Michael" <michaellehner at siemens dot com>]

> -----Original Message-----
> From: tromey@redhat.com [mailto:tromey@redhat.com]
> Sent: Tuesday, December 19, 2006 6:25 PM
> To: Lehner, Michael
> Cc: java@gcc.gnu.org
> Subject: Re: Dependencies when using gcc-generated object files in
another
> compiler
> 
> >>>>> "Michael" == Lehner, Michael <michaellehner@siemens.com> writes:
> 
> Michael> I read something about an option for gcc to use Greenhills
ABI,
> but I
> Michael> didn't figure out how to use it and if it's really supported,
> does
> Michael> anybody know?
> 
> I don't see anything in the documentation about this.
> 
[Lehner, Michael] 
It was on a mailing list, but there also was no solution.

> Michael> And our intention was even to use java for our
> Michael> operating-system-development. That means we must be able to
> Michael> compile it for MIPS itself and not for an specific operating
> Michael> system.
> 
> This can be done -- we've done it before -- but it will require you to
> do some porting work on the GC and libgcj itself.
> 
[Lehner, Michael] 
But i think it won't be possible to evaluate how much porting work I
will have to do I think?

> I looked briefly at your original note...
> 
> >> >  __gcj_personality_v0   from Main.o
> >> >  _Unwind_Resume   from gnulib.a(Class.o)
> >> >  _Jv_Throw from gnulib.a(Class.o)
> 
> Missing libgcj's exception code somehow?
> 
> >> >  __fixdfdi from gnulib.a(lt15-lang.o)
> >> >  __fixsfdi from gnulib.a(lt15-lang.o)
> 
> Missing libgcc?
> 
> >> >  _ZN4java4util5regex7Pattern7compileEPNS_4lang6StringE      from
> >> gnulib.a(lt15-lang.o)
> 
> Did you remove parts of libgcj but not update the callers?
> 
[Lehner, Michael] 
No, I took the original classpath included in gcc-4.1.1 and did not
change anything. Strange to me is also, that if I only use gcc without
Greenhills, I get an executable without any problems. I took all .o and
.a files in the lib-dir of the cross compiler I am using. Extracted the
archives and copied the objects into the same dir. Then I made a big
archive out of all the files and told the Greenhills linker, to search
in this archive too.
Problems occurred extracting libieee.a and libmcheck.a, ar tells me,
that File format is not recognized. And I had to remove mcheck.o,
strtoll_l.o, strtoull_l.o strtoul_l.o and vfprintf.o, because Greenhills
said to me, that there are symbols hat already defined in another
object.
Is there anything missing I would perhaps need for successfully
compiling?

> Anyway, to make this stuff work you'll have to dive into the guts a
> bit.  And, things could be especially problematic if your OS is
> written in C++ and throws exceptions that the caller must catch.  A
> lot depends on the details of the GH compiler, about which I know
> nothing.
> 
[Lehner, Michael] 
The OS itself is not written in C++, it is written in C, but there are a
few higher parts where C++ is used besides C. I don't know if this could
mean problems, but I think I will see. First I will have to solve the
current Problems.

Michael