Re: Don't error out when variable not available

[Andrew Cagney <cagney at gnu dot org>]

Andreas Schwab wrote:
> With the introduction of DWARF location lists it became impossible to get
> the full list of local variables of a function when any of them is not
> available.  This is especially annoying when the first local or function
> parameter is missing.  Here is an attempt at correcting this.  It is
> suboptimal because it still prints the error message including the newline
> which badly messes up the output.  Any idea how to fix that properly?

The code to catch these errors and print the message as part of the 
output has long been on my (and I suspect others) wish list.  It should, 
in addition to solving your problem, mean that gdb handles the general 
case printing for instance:

  (gdb) print struct_s
  $1 = { a = <memory error>, b = "hi" }
  (gdb)

instead of

  $1 = { a = memory error
  (gdb)

Have a look at catch_exceptions_with_msg.  It was added to handle the 
problem of needing to catch the error message (you might need to wiggle 
the interface though).

Adding more special case code, as was done with your other patch, isn't 
the way to go.

Andrew

> 2005-01-02  Andreas Schwab  <schwab@suse.de>
>
> 	* findvar.c (read_var_value_no_error, read_var_value_no_error_1)
> 	(struct read_var_value_args): New.
> 	* value.h (read_var_value_no_error): Declare it.
> 	* printcmd.c (print_variable_value): Use read_var_value_no_error.
> 	* stack.c (print_frame_args): Likewise.