RE: [patch v4 18/24] record-btrace: extend unwinder

["Metzger, Markus T" <markus.t.metzger@intel.com>]

> -----Original Message-----
> From: Jan Kratochvil [mailto:jan.kratochvil@redhat.com]
> Sent: Friday, September 27, 2013 3:55 PM


> > This has meanwhile been resolved.  This had been a side-effect of throwing
> > an error in to_fetch_registers.  When I just return, function arguments are
> > correctly displayed as unavailable and the "can't compute CFA for this
> frame"
> > message is gone.
> 
> With v6 patchset it is only sometimes gone, I still get it.
> Tested with (results are the same):
> 	gcc (GCC) 4.8.2 20130927 (prerelease)
> 	gcc-4.8.1-10.fc21.x86_64
> 
> int f(int i) {
>   return i;
> }
> int main(void) {
>   f(1);
>   return 0;
> }
> 
> gcc -o test3 test3.c -Wall -g
> ./gdb ./test3 -ex start -ex 'record btrace' -ex step -ex step -ex reverse-step -
> ex frame
> #0  f (i=<error reading variable: can't compute CFA for this frame>) at
> test3.c:2
> 2	  return i;
> (gdb) _
> 
> It gets fixed by the attached patch.

Thanks.  I'll incorporate it into the extend unwinder patch.

Given that we always throw an error for BTRACE frames, there's no
need to get the stop reason first or to skip inline frames; they won't
be mixed with BTRACE frames.

Regards,
Markus.

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