Setting breakpoints where duplicate symbols are present

Setting breakpoints where duplicate symbols are present

[Jaimon Jose]

This may be a trivial question.  I'm kind of stuck on this and didn't
find a way to work around.

I have a  process where multiple libraries are loaded.  Some of them
have duplicate symbols  ( private copies of the same symbol and the
libraries are linked with -Bsymbolic for a reason ).  I can't see the
symbol from the library in context (  in dbx I could do this by
qualifying the symbol by the library name.  For eg. `libfoo.so.1`foo_bar
) when I try to set a breakpoint or inspect the symbol.  It will always
go to a symbol from a library which is already resolved where as the one
that's getting executed is from the local library.  Because of this, the
breakpoints are never hit.

My questions are:
1. How do I inspect all the symbols of the same name in the process
space?  ( I tried loading the symbol from each library
load-symbol-file.  It didn't help either. In case of ambiguity, dbx used
to show all symbols qualified with the library name and let us choose
the right one)
2. How do I qualify a symbol with the library name where it belongs to?
( for eg.  `libfoo.so`foo_bar )

Appreciate your help
--jaimon

Re: Setting breakpoints where duplicate symbols are present

[Daniel Jacobowitz]

On Sat, May 05, 2007 at 08:26:47AM +0530, Jaimon Jose wrote:
> My questions are:
> 1. How do I inspect all the symbols of the same name in the process
> space?  ( I tried loading the symbol from each library
> load-symbol-file.  It didn't help either. In case of ambiguity, dbx used
> to show all symbols qualified with the library name and let us choose
> the right one)
> 2. How do I qualify a symbol with the library name where it belongs to?
> ( for eg.  `libfoo.so`foo_bar )

Basically, you can't.  Yet.  We know we need to fix this.

-- 
Daniel Jacobowitz
CodeSourcery

Re: Setting breakpoints where duplicate symbols are present

[Ulrich Weigand]

Daniel Jacobowitz wrote:
> On Sat, May 05, 2007 at 08:26:47AM +0530, Jaimon Jose wrote:
> > My questions are:
> > 1. How do I inspect all the symbols of the same name in the process
> > space?  ( I tried loading the symbol from each library
> > load-symbol-file.  It didn't help either. In case of ambiguity, dbx used
> > to show all symbols qualified with the library name and let us choose
> > the right one)
> > 2. How do I qualify a symbol with the library name where it belongs to?
> > ( for eg.  `libfoo.so`foo_bar )
> 
> Basically, you can't.  Yet.  We know we need to fix this.

B.t.w., Markus is currently working on a patch:
http://sourceware.org/ml/gdb-patches/2007-05/msg00037.html

that will at least have GDB follow the ld.so symbol lookup rule,
so if you access a symbol name from within a frame belonging
to a -Bsymbolic shared library, you'll get the symbol definition
from within that library.

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com