Re: GDB 10.2 Release: Proposing Mar 13-14 for official GDB 10.2 release

[Joel Brobecker <brobecker@adacore.com>]

Hi Simon,

> >> Tom Tromey and I would be good candidates to look a it,
> >> because it's related to the DWARF symbol sharing, which
> >> we've both worked on.  I will try to give it a look in
> >> the following days.
> > 
> > Thanks for the heads up, Simon. I've changed its Target Mileston
> > to 10.2 in Bugzilla.
> > 
> 
> I've been looking at this on and off for the last few days, and I don't
> think I'll be able to come up with a proper fix in a short time frame.
> And even if I did, I think it would be too risky for merging in a stable
> branch right before releasing.

That's what I was fearing already, when I saw the PR and the discussions
that were logged so far.

> The alternative I see to unblock the release is to disable the sharing of
> partial symbols between objfiles for now.  Essentially, a patch that does
> 
>     diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
>     index 704ba9f36655..5d9256bece1e 100644
>     --- a/gdb/dwarf2/read.c
>     +++ b/gdb/dwarf2/read.c
>     @@ -1954,7 +1954,8 @@ dwarf2_has_info (struct objfile *objfile,
>              doesn't require relocations and if there aren't partial symbols
>              from some other reader.  */
>            if (!objfile_has_partial_symbols (objfile)
>     -         && !gdb_bfd_requires_relocations (objfile->obfd))
>     +         && !gdb_bfd_requires_relocations (objfile->obfd)
>     +         && 0)
>             {
>               /* See if one has been created for this BFD yet.  */
>               per_bfd = dwarf2_per_bfd_bfd_data_key.get (objfile->obfd);
> 
> We can then take our time to look at a proper fix for master.

It's quite nice to see that this feature could be disabled with
a one-liner like this.

Unless Tom has other ideas, this seems like the way to go for me.

I also wanted to mention that, in terms of timing, I was planning
on starting the regular updates for the 11.1 releases pretty much
right after the GDB 10.2 is out. We will just have to list this one
right from the beginning.

Procedurally speaking, what would help is if we close the PR about
the crash with the target milestone set to 10.2 right after your patch
is in, and then re-open the PR about the partial symtab sharing to
fix the crash on master (or open a new one if there wasn't one
already). That way, anyone asking for the list of fixes from 10.1
to 10.2 would find this issue (this is something I do when publishing
a .2, for instance).

Thanks Simon!
-- 
Joel