Re: RFA: Support Windows extended error numbers in safe_strerror

[Eli Zaretskii <eliz at gnu dot org>]

> Date: Sun, 5 Feb 2006 14:34:40 -0500
> From: Christopher Faylor <cgf-please-use-the-mailinglist@sourceware.org>
> 
> On Sun, Feb 05, 2006 at 06:46:06AM +0200, Eli Zaretskii wrote:
> >>Date: Sat, 4 Feb 2006 19:15:03 -0500
> >>From: Christopher Faylor
> >> 
> >>>But it isn't the same platform, anymore than MIPS/Linux and MIPS/Irix
> >>>are the same platform.  Cygwin requires a considerable amount of
> >>>additional software to be installed, of which a large part is a system
> >>>library that presents a very different API than the native OS.
> >>
> >>The minimal amount of software required for gdb to run with Cygwin is:
> >>gdb.exe, Cygwin1.dll, cygiconv-2.dll, and cygncurses-8.dll .  You may
> >>potentially need to have the terminfo library installed, too, don't
> >>know for sure, and I'm not really interested in testing.  I wouldn't
> >>call that a considerable amount of software.
> >
> >First, I think you need the shell as well (correct me if I'm wrong).
> 
> The shell is needed for the "shell" command.  The shell is not used for
> running programs.

The latter is unlike on Posix platforms, right?

> So, yes, if you don't have a Cygwin shell, then the shell command won't
> work.  If that is a show stopper, I could have gdb revert to using a
> windows shell if /bin/sh is missing.

I don't know if that's a show-stopper: I don't use Cygwin.  But if
Cygwin users frequently have a development environment without a shell
(which I doubt is the case), then yes, having a workable `shell'
command without Bash would be a good change.

> >Second, running GDB alone is not useful.  People use the Cygwin build
> >of GDB to debug other Cygwin programs.  Just building those other
> >programs requires a more or less full Cygwin installation, including
> >the shell, Coreutils, Grep, Gawk, and whatsnot.
> 
> You've lost me.  So people *do* (because they can) download a lot of
> other packages along with gdb so that means that gdb is unacceptable as
> a native debugger?

I didn't say that; please re-read the wording you quoted.  I said:

  But it isn't the same platform, anymore than MIPS/Linux and MIPS/Irix
  are the same platform.  Cygwin requires a considerable amount of
  additional software to be installed, of which a large part is a system
  library that presents a very different API than the native OS.

So this was in the context of discussing the ``2 ports on the same
platform'' issue, not GDB being run alone.  I'm saying that a Cygwin
development environment changes the OS to a degree that it isn't the
same system anymore.

As another data point, consider this: Emacs now supports a Cygwin
build as well as a native Windows build (either with MinGW or MSVC).
The amount of Windows-specific code that is common to those two ports
is close to nil.

> >>Also, there is nothing in Cygwin which stops you from running native
> >>windows apps (e.g., a MinGW version of gcc) if that is your preference.
> >
> >Yes, there is.  But I'm sure you know that, so I won't elaborate.
> 
> I'd prefer that you did elaborate since you seem to be implying that I
> was (to put it politely) withholding information, and I have no idea
> what you're talking about.
> 
> It would not make much sense to think that the existence of the Cygwin
> DLL on a windows system would somehow interfere with the correct
> operation of a windows program since there are scores of windows
> programs running on a correctly functioning Windows system at any given
> time.  So, you can't mean that, obviously.

What I mean is that cooperation between native and Cygwin programs is
not easy, to say the least.

> If you're talking about trying to run programs under bash, then, the
> only problem that I can think of is what Daniel found - some native
> Windows programs misbehave if used with Cygwin's ttys or ptys.  The
> solution to this dilemma is the same that you'd use if Cygwin was not on
> the system - don't use ptys or ttys.  If you are a purist, then don't
> use bash.  Just run gdb directly.
> 
> I am not aware of any problems with running native windows programs
> under gdb.  If there are, then I'd be happy to look into fixing them for
> as long as I continue to be maintainer.

I'm talking about ttys and ptys.  I'm talking about Ctrl-C.  I'm
talking about incompatible quoting of command-line arguments and &&.
I'm talking about mount points and text/binary I/O.  Perhaps all this
was solved in recent versions of Cygwin, I'm just repeating what I
hear from Cygwin users around me.  Which is why I didn't want to
repeat that hearsay, but you left me no choice.

Anyway, this discussion obviously doesn't lead to any constructive
direction, so I suggest we drop it.  Our disagreements about this were
not born yesterday.  Let's concentrate on the common goals, not on
disagreements.