Retiring in-tree GDB

Slawa Olhovchenkov slw at zxy.spb.ru
Thu Jul 21 09:26:44 UTC 2016


On Wed, Jul 20, 2016 at 12:00:21PM -0700, John Baldwin wrote:

> On Tuesday, October 20, 2015 01:36:28 PM John Baldwin wrote:
> > When this topic was last raised (by Warner I believe), the primary objection
> > (certainly my main one) was that the in-tree kgdb was the only kernel debugger
> > available.  kgdb is now available via the devel/gdb port in ports (and as of
> > last week was enabled by default, so 'pkg install gdb' will get you a kgdb
> > binary).  The kgdb in ports is in general superior to the one in the base
> > system.  It is a cross debugger by default (and with my pending patches to
> > libkvm it even supports cross debugging of vmcores).
> > 
> > There are some issues still with devel/gdb: namely it does not currently
> > support some of the platforms supported by our in tree gdb such as arm and
> > mips.  For these platforms I think the in-tree gdb will need to remain until
> > there is a suitable alternative.
> > 
> > However, I would like to propose that we retire the in-tree GDB for some of
> > our platforms (namely x86) for 11.  In particular, I think we should default
> > to enabling lldb and disabling gdb for platforms that meet the following
> > criteria:
> > 
> > 1) devel/gdb works including thread and kgdb support
> > 2) lldb works
> > 
> > We could perhaps be more aggressive and handle lldb and gdb toggles
> > independently, but I think we want to ship some sort of userland debugger
> > out of the box on all of our platforms.  The question I think might be if
> > we end up with platforms where 1) is true but 2) is not (such as powerpc).
> > 
> > I believe that these conditions are only true for x86 currently.
> > 
> > Comments?
> 
> I believe I've fixed the one last thing that was depending on /usr/bin/gdb
> (crashinfo) to use devel/gdb if it is present.  I'd either like to disable
> the base gdb on amd64 in the next week or so on HEAD, or perhaps if people are
> really gutsy, disable it for all platforms on HEAD.  We still don't have kgdb
> in ports for non-x86 (though for ppc at least kgdb in ports and base is
> equally dysfunctional).
> 
> However, to start with:
> 
> 1) Does anyone have a reason to keep /usr/bin/gdb on amd64?
> 
> 2) Does anyone have a reason to keep /usr/bin/gdb on !amd64?

lldb replace /usr/bin/gdb?
lldb still bundled with base system?


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