Posted on October 09, 2012 at 09:52Hi,
I'm experiencing a strange problem with IAR EWARM and STM32F4DISCOVERY.
I have quite a deep nested 'if' function setup that is misbehaving. I have checked, double and triple checked the brackets and semicolons. I have also auto indented the function and it all matches up and looks fine.
However when debugging the code, it seems to unexpectedly jump to lines (when stepping into [F11]), that it shouldnt. The problem seems to be irrelevant to the if statements, as it sometimes
skips to a line without processing the proceeding line first
.
This is hard to explain, see short example below
g = 1;
h = 2;
if (g==1){
if (h==1){
i=1;
j=2;
k=3;
}else if (h==2){
i=2;
j=3;
k=4;
}else{
i=0;
j=0;
k=0;
}
}else{
i=8;
j=9;
k=10;
}
Obviously in this case the output should be i=2, j=3 and k=4.
But when stepping through the code, the debugger will execute in the order given by the red numbers. In green is what should happen
g = 1;
1
h = 2;
2
if (g==1){
3
if (h==1){
4
i=1;
j=2;
k=3;
}else if (h==2){
5
i=2;
6
j=3;
7
k=4;
8
}else{
i=0;
j=0;
k=0;
}
}else{
i=8;
j=9;
6
k=10;
7
}
Yes that's right, it even skips i=8!! How can this be? At least the compiler seems to be consistent with where it skips. But how/why?
Obviously my code is a lot bigger than this, but essentially this is whats happening. Could i be running out of memory/stack or something? I am using a lot of floats. I also have several timers running interrupts in the background, and this function itself is called via an interrupt.
Help!? This is doing my head in... thanks!
