Re: gdb/633: fully qualified pathnames in solib_map_sections() and remote debugging

[Daniel Jacobowitz <drow at mvista dot com>]

On Fri, Aug 09, 2002 at 04:12:06PM -0700, Kevin Buettner wrote:
> On Aug 6,  9:20am, Daniel Jacobowitz wrote:
> 
> >    Global variable SOLIB_ABSOLUTE_PREFIX is used as a prefix directory
> >    to search for shared libraries if they have an absolute path.
> > 
> >    Global variable SOLIB_SEARCH_PATH is used as a prefix directory
> >    (or set of directories, as in LD_LIBRARY_PATH) to search for all
> >    shared libraries if not found in SOLIB_ABSOLUTE_PREFIX.
> > 
> >    Search order:
> >    * If path is absolute, look in SOLIB_ABSOLUTE_PREFIX.
> >    * If path is absolute or relative, look for it literally (unmodified).
> >    * Look in SOLIB_SEARCH_PATH.
> >    * Look in inferior's $PATH.
> >    * Look in inferior's $LD_LIBRARY_PATH.
> > 
> > 
> > I think the search order needs some revision though:
> >  - A cross debugger should not search $PATH or $LD_LIBRARY_PATH
> 
> I agree with this.
> 
> >  - A cross debugger may, or may not, want to look for the unmodified
> > path; I suspect that we only want to look for unmodified relative
> > paths, not unmodified absolute ones.
> 
> I agree regarding absolute paths.
> 
> For relative paths, I'm not convinced that it's all that useful to
> look at the unmodified path.  (Doing so requires that you have your
> cwd set correctly, right?)

Yes; I think that's not too unreasonable, though.  I can go either way
on this one; I believe it never comes up in GNU/Linux since the linker
fills in the full path in the link map.  Not 100% sure of that,
however.

> > With those changes you would have to explicitly specify the path to
> > DSOs in a cross debugger via solib-absolute-prefix and
> > solib-search-path,
> 
> I think this would be good...
> 
> > and GDB would stop picking up the host libpthread.so
> > and making gdbserver segfault...
> 
> ...and this too!

This leaves only the question of "how".  I don't want to change the
behavior for a native debugger using the remote protocol; just for
non-native debuggers.  How should I check for this?  Using configury to
do it seems contrary to the direction gdbarch is going (i.e. a both
native and cross debugger in one binary).

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer