bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Ken Brown]

I've made a first attempt to port mps to Cygwin.  If anyone else is
interested in seeing this or helping, you can find my work at

   https://github.com/kbrow1i/mps-cygwin

This is a fork of the mps git repo with two commits on top.

With the current attempt, I can build the scratch/igc branch, but there
are many test failures.  For example, when I run the process-tests, I
get 19 failures and 8 skipped tests.  But on the master branch I get no
failures and only 3 skipped.

This probably means that my current attempt to port mps is no good, and
I have to go back to the drawing board.  Before I do that, however, I'd
like to check and see if test failures on scratch/igc are to be
expected.  Are people testing other platforms seeing this too?

Thanks.

Ken

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Pip Cet via Bug reports for GNU Emacs, the Swiss army knife of text editors]

"Ken Brown" <kbrown@cornell.edu> writes:

> I've made a first attempt to port mps to Cygwin.  If anyone else is
> interested in seeing this or helping, you can find my work at
>
>    https://github.com/kbrow1i/mps-cygwin
>
> This is a fork of the mps git repo with two commits on top.
>
> With the current attempt, I can build the scratch/igc branch, but there
> are many test failures.  For example, when I run the process-tests, I

But the Emacs binary "works", to some extent? Is there anything in the
process-tests.log file which hints at what kind of problem it might be?

Does it work interactively, or crash right away?

> get 19 failures and 8 skipped tests.  But on the master branch I get no
> failures and only 3 skipped.

That sounds like a "minor" GC problem; a word size mismatch or alignment
problem would probably lead to a hard crash, so it's more likely to be a
problem in scanning the stack.

I'm a bit confused about the role of prmccyi6.c; it's included in the
cyi6gc.mk fragment, but it's not included by mps.c directly. How are you
building MPS?

I see that you have defined (in prmccyi6.c)

Addr MutatorContextSP(MutatorContext context)
{
  AVERT(MutatorContext, context);
  return (Addr)context->ucontext->uc_mcontext.rsp;   /* .sp */
}

using the MutatorContextStruct from prmcix.h, which uses an ucontext.
However, you also include prmcw3.c, which uses a different definition of
MutatorContextStruct. I don't think those two are compatible, so it's
possible that's the problem, depending on how you build mps.

> This probably means that my current attempt to port mps is no good, and
> I have to go back to the drawing board.  Before I do that, however, I'd
> like to check and see if test failures on scratch/igc are to be
> expected.  Are people testing other platforms seeing this too?

I see a few test failures on Windows, but nothing as catastrophic as
what you describe.

Do you have a usable debugger/gdb on your platform? That would
be one approach to diagnosing crashes (if the problem is indeed that
Emacs crashes).  Another approach would be to run the test suite
included in MPS.

Pip

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Andrea Corallo]

Ken Brown <kbrown@cornell.edu> writes:

> I've made a first attempt to port mps to Cygwin.  If anyone else is
> interested in seeing this or helping, you can find my work at
>
>   https://github.com/kbrow1i/mps-cygwin
>
> This is a fork of the mps git repo with two commits on top.
>
> With the current attempt, I can build the scratch/igc branch, but there
> are many test failures.  For example, when I run the process-tests, I
> get 19 failures and 8 skipped tests.  But on the master branch I get no
> failures and only 3 skipped.

Is the testsuite supposed to be clean on igc on supported platforms?
Last time I asked Gerd explained me it was still not the case but maybe
things evolved.

  Andrea

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Eli Zaretskii]

> Date: Wed, 11 Dec 2024 17:50:40 -0500
> From: Ken Brown <kbrown@cornell.edu>
> 
> I've made a first attempt to port mps to Cygwin.  If anyone else is
> interested in seeing this or helping, you can find my work at
> 
>    https://github.com/kbrow1i/mps-cygwin
> 
> This is a fork of the mps git repo with two commits on top.

Thanks, good news!  Could you please post the patches here, so that
they are recorded in our bug tracker?

> With the current attempt, I can build the scratch/igc branch, but there
> are many test failures.  For example, when I run the process-tests, I
> get 19 failures and 8 skipped tests.  But on the master branch I get no
> failures and only 3 skipped.
> 
> This probably means that my current attempt to port mps is no good, and
> I have to go back to the drawing board.

Did you run the MPS test suite, and if you did, were there any
failures?  My suggestion is to make sure the MPS test suite passes
cleanly, including in several consecutive runs (when I ported MPS to
32-bit MinGW, I had intermittent failures which only happened once in
several runs, until I fixed that).

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Stefan Kangas]

Ken Brown <kbrown@cornell.edu> writes:

> I've made a first attempt to port mps to Cygwin.  If anyone else is
> interested in seeing this or helping, you can find my work at
>
>    https://github.com/kbrow1i/mps-cygwin
>
> This is a fork of the mps git repo with two commits on top.
>
> With the current attempt, I can build the scratch/igc branch, but there
> are many test failures.  For example, when I run the process-tests, I
> get 19 failures and 8 skipped tests.  But on the master branch I get no
> failures and only 3 skipped.
>
> This probably means that my current attempt to port mps is no good, and
> I have to go back to the drawing board.  Before I do that, however, I'd
> like to check and see if test failures on scratch/igc are to be
> expected.  Are people testing other platforms seeing this too?

Do we expect upstream to be amenable to eventually taking these patches?
I see that they officially only support "Windows Vista or later, on
IA-32 and x86-64, using Microsoft Visual C/C++".

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Eli Zaretskii]

> From: Stefan Kangas <stefankangas@gmail.com>
> Date: Thu, 12 Dec 2024 03:05:58 -0800
> 
> Ken Brown <kbrown@cornell.edu> writes:
> 
> > I've made a first attempt to port mps to Cygwin.  If anyone else is
> > interested in seeing this or helping, you can find my work at
> >
> >    https://github.com/kbrow1i/mps-cygwin
> >
> > This is a fork of the mps git repo with two commits on top.
> >
> > With the current attempt, I can build the scratch/igc branch, but there
> > are many test failures.  For example, when I run the process-tests, I
> > get 19 failures and 8 skipped tests.  But on the master branch I get no
> > failures and only 3 skipped.
> >
> > This probably means that my current attempt to port mps is no good, and
> > I have to go back to the drawing board.  Before I do that, however, I'd
> > like to check and see if test failures on scratch/igc are to be
> > expected.  Are people testing other platforms seeing this too?
> 
> Do we expect upstream to be amenable to eventually taking these patches?

I don't think we've asked them.  Maybe Gerd knows?

> I see that they officially only support "Windows Vista or later, on
> IA-32 and x86-64, using Microsoft Visual C/C++".

Yes.

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Gerd Möllmann]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Stefan Kangas <stefankangas@gmail.com>
>> Date: Thu, 12 Dec 2024 03:05:58 -0800
>> 
>> Ken Brown <kbrown@cornell.edu> writes:
>> 
>> > I've made a first attempt to port mps to Cygwin.  If anyone else is
>> > interested in seeing this or helping, you can find my work at
>> >
>> >    https://github.com/kbrow1i/mps-cygwin
>> >
>> > This is a fork of the mps git repo with two commits on top.
>> >
>> > With the current attempt, I can build the scratch/igc branch, but there
>> > are many test failures.  For example, when I run the process-tests, I
>> > get 19 failures and 8 skipped tests.  But on the master branch I get no
>> > failures and only 3 skipped.
>> >
>> > This probably means that my current attempt to port mps is no good, and
>> > I have to go back to the drawing board.  Before I do that, however, I'd
>> > like to check and see if test failures on scratch/igc are to be
>> > expected.  Are people testing other platforms seeing this too?
>> 
>> Do we expect upstream to be amenable to eventually taking these patches?
>
> I don't think we've asked them.  Maybe Gerd knows?

I haven't done anything like that. I've only submitted some minor Github
issue when I was playing with MPS, and I've sent them a mail to let them
know what's going on when I made what I had public here on emacs-devel.

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: Stefan Kangas <stefankangas@gmail.com>,  kbrown@cornell.edu,
>   74805@debbugs.gnu.org
> Date: Thu, 12 Dec 2024 13:06:41 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: Stefan Kangas <stefankangas@gmail.com>
> >> Date: Thu, 12 Dec 2024 03:05:58 -0800
> >> 
> >> Ken Brown <kbrown@cornell.edu> writes:
> >> 
> >> > I've made a first attempt to port mps to Cygwin.  If anyone else is
> >> > interested in seeing this or helping, you can find my work at
> >> >
> >> >    https://github.com/kbrow1i/mps-cygwin
> >> >
> >> > This is a fork of the mps git repo with two commits on top.
> >> >
> >> > With the current attempt, I can build the scratch/igc branch, but there
> >> > are many test failures.  For example, when I run the process-tests, I
> >> > get 19 failures and 8 skipped tests.  But on the master branch I get no
> >> > failures and only 3 skipped.
> >> >
> >> > This probably means that my current attempt to port mps is no good, and
> >> > I have to go back to the drawing board.  Before I do that, however, I'd
> >> > like to check and see if test failures on scratch/igc are to be
> >> > expected.  Are people testing other platforms seeing this too?
> >> 
> >> Do we expect upstream to be amenable to eventually taking these patches?
> >
> > I don't think we've asked them.  Maybe Gerd knows?
> 
> I haven't done anything like that. I've only submitted some minor Github
> issue when I was playing with MPS, and I've sent them a mail to let them
> know what's going on when I made what I had public here on emacs-devel.

So maybe we should ask them.  It could be a factor in our decision
whether we want to fork MPS and maintain our own fork.

bug#74805: 30.0.92; Trying to build scratch/igc on Cygwin

[Gerd Möllmann]

Eli Zaretskii <eliz@gnu.org> writes:

>> I haven't done anything like that. I've only submitted some minor Github
>> issue when I was playing with MPS, and I've sent them a mail to let them
>> know what's going on when I made what I had public here on emacs-devel.
>
> So maybe we should ask them.  It could be a factor in our decision
> whether we want to fork MPS and maintain our own fork.

Yes, I think something "official" from the maintainers would be a good
thing. The email I used back then to inform them of what's
going on was info@ravenbrook.com. Couldn't find something better.