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

[Daniel Jacobowitz <drow at mvista dot com>]

The following reply was made to PR gdb/633; it has been noted by GNATS.

From: Daniel Jacobowitz <drow@mvista.com>
To: Kevin Buettner <kevinb@redhat.com>
Cc: jorma.laaksonen@hut.fi, gdb-gnats@sources.redhat.com,
	gdb@sources.redhat.com
Subject: Re: gdb/633: fully qualified pathnames in solib_map_sections() and remote debugging
Date: Sun, 11 Aug 2002 23:25:27 -0400

 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