Re: [Qemu-devel] qemu & openpty

[Anthony Liguori <aliguori@us.ibm.com>]

Michael Tokarev <mjt@tls.msk.ru> writes:

> Hello.
>
> One of old issues with compatibility between different
> *Nix systems was the way how pty pairs were allocated.
>
> And qemu have a twist in #includes, depending on which
> platform it is run, and quite some compat cruft in
> qemu-char.c about this issue.
>
> Here it is, from qemu-char.c:
>
> #ifdef __sun__
> /* Once Solaris has openpty(), this is going to be removed. */
> static int openpty(int *amaster, int *aslave, char *name,
>                    struct termios *termp, struct winsize *winp)
> {...}
>
> static void cfmakeraw (struct termios *termios_p)
> {...}
> #endif

This code is gross.

> and later on, openpty() is used in the code.  Note that
> both functions are marked as static - static to the
> source file, qemu-char.c.
>
> Now, we have ui/gtk.c, which calls openpty() and cfmakeraw()
> too, but this time, there's no compat alternative implementation
> provided.
>
> Does this mean we don't need the old compat implementation
> anymore?  Does gtk ui work (or at least builds) on solaris?

I didn't carry this code over to the GTK UI because 1) I have no way to
test it 2) it adds a lot of complexity for something that may be used by
noone.

> If gtk builds fine on solaris, it should be safe to remove
> these static functions from qemu-char.c.

I think we're quickly getting to a point where we should simply state
that in order for any OS to be "supported" by QEMU, there must be a
buildbot.  Otherwise the testing burden is too high.

I'll send a top-level note with such a proposal.

Regards,

Anthony Liguori

> If not, we should obviously re-use these for ui/gtk.c --
> for which I'd create a new file, say, qemu-openpty.c,
> with all the system-dependent stuff inside, and create
> a wrapper function, qemu_openpty(), to do the work,
> and, ofcourse, remove <pty.h> and other fancy stuff
> (like <stropts.h> for solaris) from qemu-common.h (!!!)
> where it finally ended up.
>
> Thanks,
>
> /mjt