Re: [RFA/RFC] Tweak for a gdb.mi test.

[Andrew Cagney <ac131313 at cygnus dot com>]

> On Tue, May 07, 2002 at 06:09:11PM -0700, Michael Snyder wrote:
> 
>> 
>> I'm gonna ask for a second pair of eyes, since I don't know MI 
>> very well.
>> 
>> What this is -- the test is examining the stack, but it is
>> assuming that main is the last frame.  My change allows for
>> one extra frame below main (eg. for '_start').
>> 
>> OK to check in?
> 
> 
> Before you check this in, I would prefer to have a policy decision
> in place about whether we should show that frame or not.  The relevant
> macro is FRAME_CHAIN_VALID; I believe we should universally (or almost
> universally) change this to stop at main.  I think that's
> func_frame_chain_valid but don't trust my memory.

(don't remember which function either, but)
Yes, I don't think the backtrace should go past main so I think the 
change is wrong.

I remember much debate about the test at the time (it was Cygnus 
internal unfortunatly).  The thing that clinched the deal was the 
obeservation (made by a human factors person) that the behavour had to 
be consistent across platforms.  For a given OS (e.g. eCos, GNU/Linux, 
...) the backtrace should look identical, regardless of the ISA.

Having each ISA making independant, and somewhat arbitrary, decisions is 
wrong.

 From memory, a suggestion was to let people select the back-trace 
policy independant of the current architecture.

> Some ports (HP/UX comes to mind) do wacky things in this macro/method. 
> I'm not sure what they accomplish or whether they are really necessary. 
> Most default to either file_ or func_, and we should standardize that
> unless there is a good reason not to.

enjoy,
Andrew