bug#47067: 28.0.50; [feature/native-comp] Crash while scrolling through dispnew.c

[Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Andrea Corallo <akrl@sdf.org>
>> Cc: Pip Cet <pipcet@gmail.com>, 47067@debbugs.gnu.org
>> Date: Sun, 14 Mar 2021 19:00:26 +0000
>> 
>> > Andrea, is it possible to have debug level 1 produce only the debug
>> > info within the generated code, and leave the pseudo-code dump for
>> > higher levels?  If you don't have time to implement this yourself, can
>> > you instruct me what changes need to be made?  I'd like to try
>> > recompiling everything with debug level 1 and see if that helps with
>> > the backtraces.
>> 
>> Sure that's very easy (the attached should do the job), is this
>> something you'd like to have a local modification or a change in the
>> branch?
>
> I don't know yet.
>
>> If the case is the second before I'd just like to understand why the
>> Windows toolchain needs debug symbols for function names and if this is
>> a bug or the expected behavior.
>> 
>> IME this was never the case on systems I've worked on and this is why I
>> though having debug symbols and dump pseudo C code together in the same
>> debug level made sense, essentially to allow stepping.
>
> I'm not yet sure there's something special on MS-Windows in this
> regard.  After Pip's last patch I see much fewer "??" in the
> backtraces, and when they appear, there's something else wrong with
> the backtrace as a whole, for example it ends prematurely, before it
> gets all the way to 'main'.  I don't yet understand why that happens,
> but it doesn't happen right away, the first backtraces I see are
> completely normal.  My current observation is that the backtraces
> begin to show abnormalities as soon as Isearch calls sit-for (to show
> the lazy-highlight of matches).  Before that, I see no "??"
> whatsoever.

Very dumb question, I guess you are (as opposed to me) already using a
farly recent gdb correct?

  Andrea