[M3devel] recent problems?

Tony Hosking hosking at cs.purdue.edu
Sun Mar 15 22:10:05 CET 2009


You might have structure sizes wrong and your stack will get shifted  
around as the command line changes length.  You get some data in a  
structure wrong and then hit the wrong stack org and you might see  
problems like this.

I am not running things totally off of the head, so if the problem was  
introduced recently it might only now be seen.

On 16 Mar 2009, at 06:15, Jay wrote:

>
>  I'm seeing some problems lately. Maybe it is just me.
>  Some of them I've had over a week (ie: before my (most) recent  
> changes),
>  some of them even if recently appeared I verified without my (most)  
> recent changes.
>
>  On Cygwin 1.5, mklib always crashes. I haven't been able to debug it.
>  This has been over a week.
>  I've had to stop using Cygwin for Modula-3 development on this  
> machine.
>  I have a good repro but hadn't had luck yet debugging it.
>  Basically if I shorten the mklib command line (in the response  
> file) substantially, no crash.
>  There is a cut off somewhere.
>
>  On Cygwin 1.7 machine, stubgen in obliqparse usually but not always  
> hangs.
>  It hangs nowhere else.
>  This I verified occured without my recent changes.
>  I only just in the past few days tried Cygwin 1.7.
>  mklib works fine here.
>  Of course since this is somewhat intermittent, maybe it isn't a new  
> problem.
>
>  I've only tried Cygwin 1.5 and 1.7 on one machine each, separate  
> machines,
>  though they do coexist ok on one machine.
>  1.7 seemed much faster (on an unimpressive machine), though 1.7  
> binares
>  apparently don't run on 1.5 -- at least not if they use assert().
>  1.7 is a recent past or future release, a long time in the works,
>  drops Win9x support, lots of good sounding changes.
>
>  I should run m3tests more, maybe they will reveal the crash or the  
> hang as well.
>
>  On LINUXLIBC6 on one machine stubgen was crashing at least in one  
> directory.
>  But I think this stopped happening.
>
>  Cygwin being broken pushes me to other platforms more, probably a  
> good thing.
>  I'm loathe to debug the hang. When it occurs I can't see any stacks  
> in gdb. I can see in strace..
>  I think we are waiting for all the threads to suspend themselves.
>  I'll probably try moving back to Win32 threads and see if it clears  
> up.
>  I know that's not great.
>  There isn't a clear implied question and I know I should/need to  
> look into these,
>  but I also thought I shouldn't keep this to myself. I also  
> understand the philosophy
>  of stopping changes when there are problems, to stop further  
> damage, but, of course,
>  I'm very confident in my changes (always..), have been testing them  
> on other platforms,
>  and looking them over extra extra since I know of these other  
> problems.
>
>  I'm not sure any problem on Cygwin is worrisome really.
>  I think the underlying code is kind of gnarly and I don't think
>  anyone uses this platform, though people asked for it.
>  But I did have a crash on LINUXLIBC6.
>
> - Jay




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