Re: Building the 7.8.90 pretest on MinGW

[Pedro Alves <palves at redhat dot com>]

On 01/22/2015 05:27 PM, Eli Zaretskii wrote:
>> Date: Thu, 22 Jan 2015 17:03:30 +0000
>> From: Pedro Alves <palves@redhat.com>
>> CC: dje@google.com, gdb-patches@sourceware.org
>>
>> No, I mean, start a shell buffer in emacs, start gdb within that,
>> and do "layout src".
>>
>> See https://sourceware.org/bugzilla/show_bug.cgi?id=17519.
>>
>> Could you try that?
> 
> It says "TUI mode not allowed".  (Tested in GDB 7.8.1 built with TUI,
> I don't have a newer binary where I type this.)

Ok, that's before my patch, but it means that isatty returned
false, so we're good after the patch too.

> 
>>> Why would it? pipes fail the isatty test.
>>
>> Right.  I recalled that Windows isatty returns true on all
>> sorts of character devices, like serial ports or the NUL device,
>> not just consoles, but confused pipes.  Pipes are not one of
>> those.  I see that gnulib has a isatty module that checks that
>> exactly -- it uses GetConsoleMode to make sure input is a real
>> console handle.  We don't import that gnulib module presently, but
>> if we need that console check it sounds like importing that
>> module would be way to fix it.
> 
> Fix what?  

Let me rephrase it:

 We don't import that gnulib module presently, but
 if we need that console check it sounds like importing that
 module would be way to add it.

Stress on the "IF".

> TUI doesn't need this fix.  The only practical problem with
> MS runtime's isatty is that the null device doesn't fail it, but
> that's of a marginal importance for GDB, I think.  That issue is
> important for filters and other batch-style programs where redirection
> to or from the null device is frequently used.

Since pipes already fail the isatty check, I agree it's of
marginal importance.

Thanks,
Pedro Alves