Re: gdb and dynamic loader namespaces

[mathieu lacage <Mathieu.Lacage@sophia.inria.fr>]

On Mon, 2007-01-08 at 10:15 -0500, Daniel Jacobowitz wrote:
> On Mon, Jan 08, 2007 at 04:09:58PM +0100, Mathieu Lacage wrote:
> > So, I tried to figure out how I could fix this in gdb: a bit of
> > debugging shows that gdb is notified of dlmopen calls through the
> > r_debug structure since "set stop-on-solib-events 1" triggers correctly
> > an event upon dlmopen. The question then is why gdb does not add the new
> > binary to its map. Maybe someone more knowledgeable than me about the
> > layout of the gdb code source could point me to the piece of code which
> > updates and manipulates the gdb map of binaries used during symbol
> > lookup ? (I am using an x86 linux system)
> 
> It's in solib-svr4.c.  Look especially at current_sos and compare that
> to where glibc adds things in namespaces.  I doubt they're on the same
> list, and in fact they may not even be listed in the public part of
> struct r_debug.

thanks,

> 
> I'm not sure what gdb would really do with them either.  It doesn't
> support multiple namespaces of symbols.

The (probably naive) idea would be to merge them: they live in separate
address spaces so address lookups should be unique. name lookups, on the
other hand, could be non-unique but this is nothing new: gdb should
already be able to handle multiple answers for a single name lookup,
right ?

Mathieu