Re: gdb "hangs" on delay loop

[Charles Manning]

On Saturday 02 May 2009 07:03:10 Gene Smith wrote:
> With -O0 opt level, gdb refuses to step (S) over a delay loop like this:
>
> code1; //<-- steps over this OK
> for(c=0; c<10000; c++);   //<--- hangs here
> code2;
>
> If I control-c and examine c it seems to be increasing slowly.
>
> When I change the code structure like this:
>
> code1;
> for(c=0; c<10000; )
>       c++;
> code2;
>
> then I can step.
>
> This is with embedded arm. See the same thing with arm-insight and
> arm-gdb. Haven't tried this with native.
>
> Is this to be expected?

The stepping in ARM, and perhaps other CPUs, is prone to getting stuck like 
this.

To get out of this either:
* restructure code
* set break at the next line and continue.
* -if you're brave - try improve gdb :-).