Re: RFC: Mostly kill FRAME_CHAIN_VALID, add user knob

[Andrew Cagney <ac131313@redhat.com>]

>> FYI,
>> 
>> Much of this is superseeded by the frame overhaul - in particular the 
>> introduction of frame_id_unwind().  The new code doesn't even call frame 
>> chain valid!
>> 
>> Perhaphs wait for the attached [wip] to be committed and then tweak that 
>> to match your proposed policy (we can then just deprecate 
>> FRAME_CHAIN_VALID_P :-).  However, making the change in parallel 
>> wouldn't hurt.
>> 
>> Looking at my WIP, I'll need to tweak the code segment:
>> 
>> +  prev_frame->pc = frame_pc_unwind (next_frame);
>> +  if (prev_frame->pc == 0)
>> +    /* The allocated PREV_FRAME will be reclaimed when the frame
>> +       obstack is next purged.  */
>> +    return NULL;
>> +  prev_frame->type = frame_type_from_pc (prev_frame->pc);
>> 
>> so that it checks for where the PC resides and abort accordingly.
>> 
>> The attached is WIP since I still need to see it working once :-)
> 
> 
> [Small wonder if you haven't pushed the call to FRAME_CHAIN_VALID
> somewhere... that's the same sort of thing that confuses me about all
> of your frame changes...]

Sorry, I'm lost.

Andrew