Re: [Libunwind-devel] [PATCH 0/8] libunwind accuracy improvements for x86-64

[Andrew Cagney]

>> However, perhaps the thing to do here is accept, document, and even
>> deprecate is_signal_frame since it isn't reliable.  Instead,
>> reflecting the underlying implementation's need to do a step to the
>> caller and add a flag - along the lines of use_prev_instr or
>> is_interrupted - to indicate the state of the callee.
>>
>> thoughts?
>
> I'll let those with more experience speak. For our purposes a signal frame is 
> just another frame and I am unfamiliar with libunwind uses which care about 
> the distinction.

Good question.  Clients have exactly the same issue as you've found
and fixed in libunwind!  They need that same 100% reliable mechanism
for identifying a frame was interrupted/signalled, and hence decide if
they should use_prev_instr when looking up debug information.

This is different, but related to is_signal_frame.