gdb functionality query

[Peter Leggett <P dot Leggett at gre dot ac dot uk>]

Hello,

I hope that this list is the appropriate one to ask a general
gdb question. If not please excuse this mail.
                                             
The research group I work in uses the Sun debugger/dbx which has some
these extremly useful features without which we would find debugging
our codes much harder. We are now also running on linux boxes
and are exploring the possibilites of gdb.

I would very much appreciate it if anyone could tell me if gdb has
the following specific functionality:-
  
a) Ability to pop program call frame stack and then continue. I know one
   can browse up and down the frames in gdb but can one pop it and      
   continue from a calling frame up the stack.                    
  
b) make an arbitary call to user code (with possibly arguments and
   expressions) from gdb  and break point within that call etc..  
   e.g.
       
   gdb-> break usersub
   gdb-> call usersub(a,fred+2,jim*2+1)
   ...                                 

   where a, fred and kim are user variables.
   
Thank you

Pete

--
  
Dr Peter F. Leggett                  Tel: +44 (0)20-8331-8731
Parallel Processing Research Group   Fax: +44 (0)20-8331-8665
University of Greenwich            Email: P.Leggett@gre.ac.uk
Maritime Greenwich Campus       Internet: http://www.gre.ac.uk/~lp01
30 Park Row
London SE10 9LS