[kaffe] patch for kaffe1.0.7jit3 code runing on MIPS

[Dalibor Topic]

Casey Marshall wrote:
>>>>>>"Dalibor" == Dalibor Topic <robilad at kaffe.org> writes:
> 
> 
> Dalibor> Yoshiharu Oba wrote:
> 
>>>Hi Dalibor I appreciate your advice very much. Now I'm writing a
>>>changelog and remake a new patch, It's also included.
> 
> 
> Dalibor> Thanks a lot! I'll go through it, and see what needs to be
> Dalibor> applied to the CVS head. It's great that you got JIT & JIT3
> Dalibor> to work. I'd like to get your changes in, and then look at
> Dalibor> Casey's patches for JIT & JIT3 from this spring.
> 
> One thing I was not able to fix in JIT3 was the stack unwinder, which
> is a particularly bad piece of code. The real problem was that GCC
> would reorder instructions in the prologue, so the unwinder was not
> able to find where the function stored $ra. I haven't tried a more
> recent GCC (I was using 3.1), but I think using `-fno-reorder-insns2'
> fixes this particular problem.
> 
> Also, I really don't much like that unwinder in general. It makes too
> many assumptions about the way the stack looks, which may not be true
> in general. GCC's unwinder makes a bit more sense, since it uses
> debugging info it will typically be consistent.

Is there some general stack unwinder library/API we could use for that? 
I've seen that mprotect has some code for such things for mips, sparc, 
i386, etc. How does gcc/gcj deal with that problem?

cheers,
dalibor topic