Re: solib search algorithm for cross-gdb

[Kris Warkentin <kewarken at qnx dot com>]

Daniel Jacobowitz wrote:

> On Wed, Aug 03, 2005 at 09:38:18AM -0400, Paul Koning wrote:
>  
>
> > Currently, the shared library search in solib.c first tries to use the
> > shared lib filename as given (if solib-absolute-prefix isn't set).
> >
> > That's exactly right for a native gdb, but it is in general the wrong
> > answer for a cross-gdb.  If I'm debugging a mips box, or analyzing a
> > mips corefile, resolving shared lib symbols from intel shared libs in
> > my /usr/lib is the wrong thing.
> >
> > .gdbinit helps, but not everyone remembers to do this right every
> > time.
> >
> > I was thinking about having the case of "use the filename exactly as
> > supplied" in solib.c be used only in native gdb.  That seems to
> > require adding stuff in configure and config.in to tell a native from
> > a cross build.
> >
> > I could submit this patch if it sounds like a good feature (otherwise
> > I'll probably keep it as a private change).  Comments?  Better ways to
> > do this?
> >    
>
> There's an argument that this should be based primarily on the target. 
> Using the native files is generally right for target "child"; generally
> wrong (though not necessarily) for target "remote"; and generally right
> for target "core" iff this is a native GDB.
>
> I don't know if that's worth implementing.  I'm inclined to say that
> your suggestion is progress, at least.

There's also the argument that it's almost never correct to be cross 
debugging _without_ solib-absolute-prefix set.  I had put in the 
TARGET_SO_FIND_AND_OPEN_SOLIB hook to give targets custom ways of 
finding their own stuff but I put it after the check for the literal 
path so it would play nicely with native debugging.

A really clever fix would be to check the architecture of found solibs 
and discard them and keep searching if it doesn't match (printing a 
warning perhaps).  Of course, that could still get the wrong library...  
Almost impossible to guarantee that you never get the wrong lib I 
think.  Fools are too ingenious. ;-)

cheers,

Kris

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