Re: [patch/rfc] Add a sentinel frame

[Andrew Cagney <ac131313@redhat.com>]

>> No.  GDB is trying to perform:
>> 
>> 	pop_frame (get_current_frame())
>> 
>> with the assumption that it has a dummy frame and get_current_frame() 
>> will return it.
>> 
> 
>> >That's what happens on i386 IIRC...
> 
> 
> I thought that we wouldn't reach frame_chain_valid if the next frame
> was a dummy frame.  Hmm, that only seems to happen for deprecated
> generic dummy frames:

The variable `use_generic_dummy_frames' is deprecated because it is 
redundant.  All targets should use generic dummy frames.  Yes, the 
variable name is screwed up :-(

>   if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
>       && DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi), 0, 0))
>     return 1;

> Oh I didn't realize the contents of frame_chain_valid had ended up
> repeated in get_prev_frame, I've been looking at the wrong function.
> That's why I didn't understand you.  Should the check above exist in
> get_prev_frame also?

When you first committed that stuff, I warned you that would happen :-)
The above test handled differently.

> [Why does this logic need to be in more than one place?]

Because frame_chain_valid() is only there to keep legacy code working. 
Need to rename it, need to deprecate the rest of those old methods.

Andrew