topic Re: Problem with local variables when debugging with CW 4.5 and 9s12X in CodeWarrior for MCU

Problem with local variables when debugging with CW 4.5 and 9s12X

calou — Fri, 20 Apr 2007 20:24:21 GMT

Hello,

I have this function :

BYTE GainToIndice(BYTE gain)
{
BYTE i,g,ind;
SBYTE diff;

g=0xFF;
for (i=0;i<BufConfig.nbgains;i++)
{
   diff=BufConfig.gains[i].gain-gain;
   if (diff<0)
     diff=-diff;
   if(diff<g)
   {
     g=diff;
     ind=i;
   }
}
}

I call it in my main program like GainToIndice(100)

When i debug it and look for example gain the value is 255. The value of i is always 52 whereas BufConfig.nbgains is 12, the value of g never changes (always 0). However the result is true.

I have tried a lot of -on optimisations but i didn't find the correct for my problem.

Thank you

Regards

Re: Problem with local variables when debugging with CW 4.5 and 9s12X

CompilerGuru — Sat, 21 Apr 2007 00:56:14 GMT

I invented the missing parts (like the BufConfig struct) and stepped once through your code and it looks ok to me. i was incrementing properly.
The only reason I could imagine your behavior is if the debugger is not able to read the stack, but then it would not behave properly. Can you check if the location the debugger shows for the i variable is the one the code is using?
Also note that your code below does not have any effect at all. GainToIndice is missing a return, and also no global is ever written.

Daniel

PS: I take "However the result is true." as it steps through the code as you expect it too. There is no result or side effect in that code to observe.

Re: Problem with local variables when debugging with CW 4.5 and 9s12X

calou — Mon, 23 Apr 2007 14:28:10 GMT

Hello Daniel,

In my code i forgot to paste return(ind).

I don't understand very well your question. When i put a breakpoint on diff=BufConfig.gains[i].gain-gain for the firs time

I have :

diff = \x00 (0)
g = \xD5 (213)
gain = 'x' (120)
i = \x00 (0)
ind = \x95 (149)
It is very strange. And the values depends where i put the breakpoint!

I note too that when i check gain, its value is the result of BufConfig.gains[i].gain-gain

Thank you for help

Regards

Re: Problem with local variables when debugging with CW 4.5 and 9s12X

calou — Mon, 23 Apr 2007 20:25:59 GMT

Hello again,

My problem is solved. It was a bug of my debugger. An update of the debugger software and now it is good.

Regards

Re: Problem with local variables when debugging with CW 4.5 and 9s12X

CompilerGuru — Wed, 25 Apr 2007 01:17:29 GMT

Just wondering, which debugger do you use?

Daniel