Re: [RFA] windows-nat.c: Enable processed input at startup

Christopher Faylor
2010-04-26T18:24:12Z

On Mon, Apr 26, 2010 at 05:47:45PM +0200, Pierre Muller wrote:
>> >> setting was global.
>> > Of course I should close the handle as soon as I changed the
>> >console mode.
>> > What about this version?
>> >
>> >Pierre
>> >
>> >2010-04-26 Pierre Muller <muller@ics.u-strasbg.fr>
>> >
>> > * windows-nat.c (_initialize_windows_nat): Try to set
>> > ENABLE_PROCESSED_INPUT for console mode if accessible.
>>
>> Ok with the minor comment changes below.
> Did you mean something to change to the comments
>inside the patch?
>
>> I don't understand why this would be necessary for Cygwin but,
>
> Did you try the example code I sent to gdb mailing list?
> This executable does change the Console Mode of a Cygwin tty
>and that change is kept after the program exits.
> This is not the case for a usual Windows command prompt.
> If you compile my program and run it.
>./test
>New console mode is 0x18
> (interrupting this works for both Ctrl-C and Ctrl-Break)
>but if you now run
>gdb gdb
>....
>(gdb) set prompt top>
>
>top> run
>...
>Try to hit Ctrl-C now, nothing happens
>(exit using q)
>Run again my test program with an argument:
>./test 1
>New console mode is 0x19
>Do the same...
>This time Ctrl-C works.

How is this a cygwin-specific problem? You can do the similar things on
linux by resetting CTRL-C handling. Does gdb accommodate that? If so,
then whatever works for linux should work for Cygwin.

>>if it is, then tcsetattr should be used.
>
From winsup/cygwin/fhanlde_console.cc I suppose that I should use
>tcsetattr (tcgetattr (h) | ISIG, h); But what should the variable 'h'
>be be initialized?

Uh, what? You can't call a lowlevel Cygwin function from outside of the
DLL. You'd need to use the tcsetattr API. Again, this would be similar
to the way UNIX/Linux handle it and I would think that Cygwin would be
able to use whatever code they use.

cgf