[kaffe] Cygwin status update

[Dalibor Topic]

Hi Jim,

Jim Pick wrote:
> On Tue, 16 Dec 2003 00:57:44 +0100
> Dalibor Topic <robilad at kaffe.org> wrote:
> 
> 
>>hi all,
>>
>>I've been playing with Cygwin & kaffe last week, and I've got patches to 
>>gradually merge in, that let kaffe build again as a static binary.
> 
> 
> Excellent.

done.

>>It doesn't fully work, as the kjc step to build rt,jar crashes. 
> 
> 
> I don't think that step ever worked.
>  

It did, that's the funny bit. I assume the crash is due to me not 
implementing the signal handling bit, I'll look at it during the weekend.

>>Investigation about it shows me that the old findJarFile bug still 
>>strikes on Cygwin. This time I was able to figure out a little more, though.
>>
>>The problem seems to be that the first few bytes of the findJarFile 
>>function in kaffe/kaffevm/jar.c somehow get overwritten. I've tried to 
>>debug it with awatch in GDB, but didn't suceed in catching the 
>>overwriting happen. So I'd be glad to hear tips & tricks on dealing with 
>>that type of bugs from other developers.
> 

I've got bad news. The byte flipping happens before main is called at 
all. This will be a hard bug to shoot down.

> Valgrind is what you want!
> 
>   http://valgrind.kde.org/
> 
> It'll tell you exactly where to look, usually.

Ah, yes. But there is no cygwin port afaik :( But maybe I can try other 
memory checkers (dmalloc, efence) if they have been ported to Cygwin.

> I did get it to run Kaffe interpreter x86 binaries on Linux.
> 
> Using it with the JIT is a problem because Valgrind needs to be
> explicitly informed about self-modifying code (because it is an
> x86-to-x86 JIT itself).  There is a way to add "hints" to the
> code to help Valgrind do the right thing, but I didn't figure
> that out yet.
> 
> For cygwin, some people have managed to get valgrind to run wine, so
> it's possible to run it against Windows binaries that work with wine. 
> Scary, huh?

I think the 'cygwin on wine' project hasn't got very far ;)

cheers,
dalibor topic