Re: RFC: Mostly kill FRAME_CHAIN_VALID, add user knob

[Andrew Cagney <ac131313@redhat.com>]

>   /* If we're inside the entry file, it isn't valid.  */
>   /* NOTE/drow 2002-12-25: should there be a way to disable this check?  it assumes a single small entry file, and the way some debug readers (e.g. dbxread) figure out which object is the entry file is somewhat hokey.  */
>   if (inside_entry_file (frame_pc_unwind (fi)))
>     return 0;
> 
> Should this one be dropped?  If the user specified unwind past main, then they problably want _start() included in the backtrace.  It's presence also makes the other inside_entry_file() test redundant. 

Er, I think it should definitly be dropped.

The big outstanding problem I've had with the frame rewrite is with 
trying to re-order FRAME_CHAIN() and FRAME_SAVED_PC() (aka 
frame_pc_unwind) - the `unwind the pc first' code.  I found, for the 
PPC, that re-ordering things caused test regressions.

I think the above runs the exact same risks.  If not for the PPC, for 
some other target.  Besides, the other inside_entry_file (get_frame_pc 
(fi)) test makes it redundant.

enjoy,
Andrew