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* How to loop in python extension while accepting mi-commands?
@ 2022-03-10 19:40 Simon Sobisch
  0 siblings, 0 replies; only message in thread
From: Simon Sobisch @ 2022-03-10 19:40 UTC (permalink / raw)
  To: GDB Mailing list

I've created an auto-step command (something like that in-built would be 
quite nice), both the "easy" and "nearly full" implementation can be 
found with some explanation at

At its core the command does:
         # recognize the kind of stop via stop_handler_auto_step
         global last_stop_was_simple
         last_stop_was_simple = True

         # actual auto-stepping
             while last_stop_was_simple:
         # we just quit the loop as requested
         # pass keyboard and user errors unchanged
         except (KeyboardInterrupt, gdb.GdbError):

with a handler of

def stop_handler_auto_step(event):
     # check the type of stop, the following is the common one after
     # step/next, a more complex one would be a subclass (for example
     # breakpoint or signal)
     global last_stop_was_simple
     if not type(event) is gdb.StopEvent:
         last_stop_was_simple = False

This works in general on the console, steps with a pause as setup and 
you can follow the code execution.

It stops on breakpoints and other "events" and when issuing CTRL-C the 
code receives the KeyboardInterrupt and is stopped, too.

The problem with this code: while an application can send 
-exec-interrupt 10 times GDB seems to queue that because the 
user-command is still active.

After the loop is ended, for example by a breakpoint, the MI-side 
receives 10 times a "done" response - so there's more than guessing that 
GDB seems to queue the commands.

I've tried to move the loop into a python thread via 
"thread.start_new_thread(loop_func(sleep_time)" and while the stepping 
worked the -exec-interrupt was still not received.

Side note:
gdb (in this case 9.2 but similar was seen in newer versions) was 
started with "-iex set pagination off -iex set mi-async on".

* Is there a way to accept mi-commands while running in Python extension 
in general?
* Is there a better approach for the auto-step than a loop like the one 
above, ending depending on KeyboardInterrupt or a gdb event happens?
* Is there any chance that a command like can be added into GDB? If yes: 
would it be helpful to send the "full" python extension script to 

Thanks for any comments,

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2022-03-10 19:40 How to loop in python extension while accepting mi-commands? Simon Sobisch

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