[PD] Crasher bug found...

Mathieu Bouchard matju at artengine.ca
Mon Feb 2 18:39:15 CET 2009

On Mon, 2 Feb 2009, Miller Puckette wrote:

> I'll check this out - I've had a couple of wierd moving crashes before 
> and it's largely as Mathieu says, switching stuff around and using some 
> intition.

I don't know whether you use Valgrind, but I would very much recommend it. 
It runs your programme in a sort of emulator that checks all memory 
accesses. It can help you find a lot more bugs than gdb can. It can tell 
you whether it's an uninitialised pointer, dangling pointer, double 
free, buffer overflow, etc., and give you both a backtrace of the problem 
and a backtrace of the related malloc (!!!).

The main downside is that there can be a lot of false positives, so you 
have to learn to recognise those as such and perhaps have to make yourself 
a "suppression file" to hide them.

The other main downside is that it can't find most stack-related problems 
because that would require the collaboration of the compiler. But most of 
the trickiest bugs tend to be malloc-related rather than stack-related.

Of course you can't debug everything with valgrind and this is why I also 
use gdb.

I wish gdb were more customisable, so that for example it could print a 
t_symbol * like:


for example. it could save a lot of time.

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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal, Québec

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