mi, new-ui and the target

mi, new-ui and the target

[Bob Rossi]

Hi,

I maintain cgdb, a curses based front end to gdb.
I got a bug report here,
  https://github.com/cgdb/cgdb/issues/352
that i'm trying to resolve.

In one terminal i run
    valgrind --vgdb-error=0 ./main.

In another terminal i run
    gdb --ex "new-ui mi /dev/pts/12" --ex 'target remote | vgdb'
From a 3rd terminal i run 'tty' to get /dev/pts/12.

Now, when i run 'monitor help' from the gdb terminal, i get this:
    (gdb) monitor help
    (gdb) 
please note the second prompt displayed by gdb.

In the third terminal, represented by /dev/pts/12, i see the proper
valgrind output. For instance,
  @"general valgrind monitor commands:\n"
  ....
  @"\n"
please note, it does not end with a (gdb) prompt or with ^done.

My issue is as follows. When i try to take the target output specified
by @ and display it in the gdb window within cgdb, gdb decides to print
to stdout it's primpt (gdb), in the middle of the target output.
So I end up with the prompt randomely in the middle of the target
output and not at the end.

Is there any way to synchronize this text properly?

Please remember the point of the new-ui feature is to allow the user to
type the commands they want, and have the front end run the commands it
wants, in these should work together in a natural way.

Thanks,
Bob Rossi

Re: mi, new-ui and the target

[Tom Tromey]

>>>>> "Bob" == Bob Rossi <bob@brasko.net> writes:

Bob> My issue is as follows. When i try to take the target output specified
Bob> by @ and display it in the gdb window within cgdb, gdb decides to print
Bob> to stdout it's primpt (gdb), in the middle of the target output.
Bob> So I end up with the prompt randomely in the middle of the target
Bob> output and not at the end.

Bob> Is there any way to synchronize this text properly?

Bob> Please remember the point of the new-ui feature is to allow the user to
Bob> type the commands they want, and have the front end run the commands it
Bob> wants, in these should work together in a natural way.

This appears to be a bug in new-ui.

In particular, mi_interp::resume sets gdb_stdtarg but nothing ever
resets it in this scenario.

Could you file a bug report for this?

I don't know how this code is really supposed to work.
Maybe gdb_stdtarg* all have to be macros like gdb_stdout et al.

Or maybe some command executor somewhere should resume the tty's
interpreter before invoking the command.

I don't really understand the design of the ui/interpreter code.  To me
it seems a lot more convoluted than is really desirable or necessary.

Tom

Re: mi, new-ui and the target

[Tom Tromey]

Tom> In particular, mi_interp::resume sets gdb_stdtarg but nothing ever
Tom> resets it in this scenario.

Tom> Could you file a bug report for this?

I have a patch for this, but as always, writing the test is a lot harder
than writing the patch itself.  So it might be a while before I send it.

Tom