Abort backtrace when consecutive zero PCs?

[Andrew Cagney]

> Andrew Cagney <cagney@gnu.org> wrote:
> 
>>> While we definitly need to allow a backtrace through a single zero PC 
>>> (for a NULL pointer call - signull.exp) should we make GDB abort when 
>>> two or more consecutive frames have a zero PC?
> 
> 
> Perhaps abort it after an identical frame is seen a second time?
> It's not the zero-ness that kills us, it's the repetition.

For the case I'm looking at, successive frames have a zero PC and a 
monotonic changing stack pointer, so there is no repetition.

Andrew