> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]On Behalf
> Of Gerhard Fiedler
> Sent: 27 April 2005 15:13
> To: Microcontroller discussion list - Public.
> Subject: Re: [PIC] HiTech C and Local Variables
>
>
> James wrote:
>
> > The contents of temporary local variables in some of my functions are
> > getting overwritten without reason. By changing them to static it fixes
> > the problem.
>
> > At no point does any of my code write to an address in RAM except via a
> > pointer to a variable, so I can't see how these variables are getting
> > overwritten.
>
> As you've been told already, since you are using pointers, nothing in the
> PIC's address space is safe anymore :)
>
> Local automatic (non-static) variables are only valid as long as you are
> executing the function that declares them or any function called by it. So
> it's likely that the problem is in one of these places.
>
> If for example a function called by the one of which the local variables
> get overwritten uses a pointer to its own local variables and the pointer
> goes out of bounds, it could easily overwrite the local variables of the
> calling function -- they may be right next to the function's own local
> variables. Of course, declaring those overwritten variables removes /that/
> symptom of the problem, but doesn't really solve the problem :)
>
>
> > I could raise this on HiTech's forum but that gets little traffic. I'm
> > really looking for any experiences from people here that could backup or
> > otherwise what I think I'm seeing! Many thanks.
>
> I've found that it's worth it to use the forum. It may have less traffic
> overall than this list, but it's more targeted.
>
> Gerhard
> --

Thanks Gerhard. I'll take a very close look, statically, at the code to see
what might be happening. I'm guessing it will be obvious _once_ I see it!

James

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