Re: Questions about GDB-MI Interface

[chanskw at ca dot ibm dot com]

Thank you.  I will definitely look at Apple's solution to this problem.

Just to clarify things a bit, will GDB continue to support CLI in MI-mode,
even after the complete set of mi-commands are implemented?  Statements
regarding not supporting CLI in MI and its eventual removal are no longer
valid?

In GDB's User's Guide:

     This mechanism is provided as an aid to developers of GDB/MI
     clients and not as a reliable interface into the CLI.

in mi/mi-main.c, where the CLI command forwarding is done, that says

     /* A CLI command was read from the input stream */
     /* This will be removed as soon as we have a complete set of
     mi commands */

Before we decide to go down the path of switching to MI, we need to confirm
that CLI-in-MI capability will continue to be available for us to provide a
console window for our users.

Regards,
Samantha Chan




                                                                                                          
                    Andrew Cagney                                                                         
                    <ac131313@cygn       To:     Samantha Chan/Toronto/IBM@IBMCA                          
                    us.com>              cc:     gdb@sources.redhat.com                                   
                                         Subject:     Re: Questions about GDB-MI Interface                
                    04/24/2002                                                                            
                    10:55 AM                                                                              
                    Please respond                                                                        
                    to Andrew                                                                             
                    Cagney                                                                                
                                                                                                          
                                                                                                          




> 2.  On the same topic, when we use CLI-in-MI we see that we sometimes get
> pure CLI output,  sometimes pure MI output, and sometimes a mixture of
> both.    The Users Guide hints that this is normal, when it says to
expect
> an "unsupported hybrid of GDB/MI and CLI output", but we don't know if we
> can provide a reliable and high-fidelity console window under these
> conditions.   Do you have any suggestions how we should proceed, or how
> other front ends have dealt with this?
>
> Ideally, we'd like to let our users continue to use the CLI, and see
> CLI-style output, while our GUI simultaneously interacts with gdb using
MI.
> So we'd like to change the definition of MI to support this, and have all
> commands change their output style based on whether they are invoked via
> the CLI or MI.
>
> We found one of the recent discussions from GDB Mailing List addressing
> this specific problem:
>
> http://sources.redhat.com/ml/gdb/2002-04/msg00348.html
>
> Apple has implemented a solution to allow front-ends to switch GDB's
> interpreter between MI and CLI.  This solution will allow frontend to
relay
> commands entered by user to GDB, and responses coming back from GDB will
be
> in CLI-style.  CLI-style responses can be sent back to our console window
> and will be meaningful to users.

Can I encourage you to look at Apple's contributed code. See:
ftp://sources.redhat.com/pub/gdb/contrib/apple/
As was noted by JimI, they came up with a way to address the problem.

You could even consider extracting the relevant changes from the patch.
  However, before doing this, you would need to establish a GDB
copyright assignment/disclaimer.

With regard to annotations and using GDB's CLI directly, I really would
discourage this.  They are both largely untested(1) and make your code
reliant on the behavour of the underlying CLI (something you can assume
will change).

Andrew

(1) Some what ironically, it was the MI developers that added the
annotation tests to GDB.