Re: [RFA] Don't use thread_db on corefiles

[Daniel Jacobowitz <drow@mvista.com>]

On Fri, Dec 14, 2001 at 09:31:10PM -0500, Andrew Cagney wrote:
> >Oh, is that what you were talking about?  Sorry, I must have been
> >>confused.
> >>
> >>So -- you are talking about building a single GDB that can debug
> >>1) native x86 linux, and
> >>2) MIPS multi-threaded linux corefiles.
> >>
> >>Is that right?
> >
> >
> >Well, that's not actually something I need to do, but I'd like it to be
> >possible.  I only need for both native and cross-hosted debuggers to
> >both be able to get at the core files.  But as things stand now, if we
> >fix thread_db to be able to do so using lin-lwp, then the native and
> >cross debuggers will get at the threads using completely different
> >interfaces.  That worries me.
> 
> 
> At a technical level, it would mean making the thread:lwp mapping 
> library multi-arch.  I think Michael gave a good summary - that isn't a 
> free lunch.  (1)
> 
> Returning to the problem at hand though,
> 
> If you build --target=mips-unknown-linux-gnu does the resultant GDB 
> include the native thread-db code?  Surely it doesn't since, as you 
> point out, it can't work.  For the moment, would only be able to display 
> threads, just the raw LWPs.

Indeed, it doesn't include thread-db.  It displays only the raw LWPs,
which suffices in the present model.

> Hmm, perhaps it is a native GDB looking at a threaded core file?  In 
> that case, yes the thread-db should drop its self on top.  If that is 
> causing an internal error then there is something messed up that should 
> be fixed.

Yes, that's where the internal error is.  They're based on the fact
that thread-db tries to enable event reporting, as best I can tell.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer