gmane.comp.gnu.mingw.user

Re: Fixing mingw support in Python's distutils

Oscar Benjamin — 2013-05-21T13:45:54

I'm not sure but I think that further modifications to distutils would
be necessary to support cygwin's cross-compilers:
http://bugs.python.org/issue12641#msg165182

This is what I suggested on the issue tracker:
http://bugs.python.org/issue12641#msg189748

My proposal is to remove '-mno-cygwin' from distutils in Python 3.4
and to only use it for gcc 3.x in Python 2.7, 3.2 and 3.3. If anyone
sees a problem with that approach I would be very grateful if you
could let me know.

Thanks again,
Oscar

------------------------------------------------------------------------------
Try New Relic Now & We'll Send You this Cool Shirt
New Relic is the only SaaS-based application performance monitoring service
that delivers powerful full stack analytics. Optimize and monitor your
browser, app, & servers with just a few lines of code. Try New Relic
and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may
_______________________________________________
MinGW-users mailing list
MinGW-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org

This list observes the Etiquette found at
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same. Disregard for the list etiquette may cause your account to be moderated.

_______________________________________________
You may change your MinGW Account Options or unsubscribe at:
https://lists.sourceforge.net/lists/listinfo/mingw-users
Also: mailto:mingw-users-request-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org?subject=unsubscribe

Re: Fixing mingw support in Python's distutils

Earnie Boyd — 2013-05-21T13:27:19

Setting a requirement for a specific version of GCC within the
distutils package should be easy enough.  Those with older versions of
GCC would just need to use the older distutils package.

Re: Fixing mingw support in Python's distutils

Keith Marshall — 2013-05-21T12:25:24


One related point you may wish to consider: even if such users of legacy
cygwin do exist, there's nothing to prevent them from setting up more
conventional mingw32-gcc cross-compiler configurations, within their
existing cygwin installations.  They should be strongly encouraged to do
so, thus allowing -mno-cygwin to be consigned, forevermore, to the scrap
heap of history, where it rightfully belongs.

Re: Fixing mingw support in Python's distutils

Oscar Benjamin — 2013-05-21T11:34:08

Brilliant. Thanks for that. The next part of that message is also very
interesting:

| gcc-4 series releases will not support it at all. As the whole thing is
| (still) experimental and explicitly warned to be unstable I don't
see the need
| to go for a deprecation period.

I guess that means that cygwin users of the arrangement that Paul
described should also see this bug when using any gcc 4.x. This is
certainly true of gcc 4.5.3 in my own old and unused cygwin
installation:

$ gcc --version
gcc (GCC) 4.5.3
Copyright (C) 2010 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ gcc hello.c
$ ./a.exe
Hello World
$ gcc -mno-cygwin hello.c
gcc: The -mno-cygwin flag has been removed; use a mingw-targeted cross-compiler.

If there were people using distutils' mingw32 mode with cygwin's gcc I
would have expected this to have been reported on the Python issue
tracker but it is not. This seems like reasonable evidence that people
are not actually using this setup even if I can't prove that it is
impossible.

This is the only possible breakage and it concerns a possibly
non-existent group of users who are abusing distutils' mingw32 mode to
compile with a now-abandoned, experimental feature of a legacy cygwin
compiler. Hopefully this obscure, possible breakage can be outweighed
by the definite, known breakage in distutils' support for using any
recent and future mingw compilers in the appropriate way as described
in the distutils docs.

Thanks everyone. I think I have more than enough information now. I'll
take this over to the Python issue tracker.

Oscar

This list observes the Etiquette found at
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same. Disregard for the list etiquette may cause your account to be moderated.

Re: Fixing mingw support in Python's distutils

Greg Chicares — 2013-05-20T15:58:40

[...]

http://cygwin.com/ml/cygwin/2009-03/msg00802.html
|  gcc-3 -mno-cygwin still works just as well (or badly!) as it ever has done,
| and will be retained for ever.

Some people may still be using Cygwin gcc version 3, which needs
'-mno-cygwin'. Those are the only people who might be affected.


------------------------------------------------------------------------------
AlienVault Unified Security Management (USM) platform delivers complete
security visibility with the essential security capabilities. Easily and
efficiently configure, manage, and operate all of your security controls
from a single console and one unified framework. Download a free trial.
http://p.sf.net/sfu/alienvault_d2d
_______________________________________________
MinGW-users mailing list
MinGW-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org

This list observes the Etiquette found at 
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same.  Disregard for the list etiquette may cause your account to be moderated.

_______________________________________________
You may change your MinGW Account Options or unsubscribe at:
https://lists.sourceforge.net/lists/listinfo/mingw-users
Also: mailto:mingw-users-request-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org?subject=unsubscribe

Re: Fixing mingw support in Python's distutils

Paul Moore — 2013-05-20T14:54:02

Sorry - I gave the wrong impression. Yes, this is a completely wrong
approach. And no, nobody should be doing this. The Python fix (to get rid
of -mno-cygwin from the flags distutils supplies) is held up by backward
compatibility concerns that people *are* doing this and making them change
their process is a compatibility breakage (for better or worse, distutils
is in a "somewhat frozen" state where all compatibility breakage, no matter
how justified, is essentially impossible to get approved).

The OP is trying to gather evidence that it is *not possible* for people to
be relying on the existing broken behaviour, because it cannot produce
viable executables (the only versions of gcc that could exist anywhere
which accept -mno-cygwin, do not support building with the version of
MSVCRT that Python needs). If he can *prove* that there are no users who
will be adversely impacted by the change, it might be possible to get the
change moving at last.

The change the OP is pursuing is precisely what you suggest - removing
-mno-cygwin from Python's distutils.

Paul
------------------------------------------------------------------------------
AlienVault Unified Security Management (USM) platform delivers complete
security visibility with the essential security capabilities. Easily and
efficiently configure, manage, and operate all of your security controls
from a single console and one unified framework. Download a free trial.
http://p.sf.net/sfu/alienvault_d2d_______________________________________________
MinGW-users mailing list
MinGW-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org

This list observes the Etiquette found at
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same. Disregard for the list etiquette may cause your account to be moderated.

Re: Fixing mingw support in Python's distutils

Oscar Benjamin — 2013-05-20T14:50:55

I think given what's been said in this thread that it's a no-brainer
that this patch needs to go into the next Python version. However,
there is also the issue of older releases. If this is a bug and not a
feature then it can possibly be fixed in already released Python
versions.

However a change of that sort needs to be demonstrably
backward-compatible. If someone was using an older version of cygwin
in the way that Paul describes then fixing distutils this way in a
bugfix release could break some system that they have and this may not
be considered acceptable. This is why I was trying to prove that no
version of mingw could exist to satisfy the constraints imposed by
Python/distutils.

I see now that there is no problem with mingw and that cygwin is in
fact the issue and I'm trying to pin down when the change occurred in
cygwin. So far grepping the gcc change logs has been inconclusive:
Documentation of the deprecation of -mno-cygwin was added in 2009
which I guess is the patch discussed in these threads:
http://gcc.gnu.org/ml/gcc-patches/2009-03/msg01051.html
http://cygwin.com/ml/cygwin/2009-03/msg00772.html
Before that the next reference to -mno-cygwin is in 2003. The
changelog entry "Disable spec when -mno-cygwin" from 2010-04-01 is the
closest I can find to the option being removed from gcc:
http://gcc.gnu.org/viewcvs/gcc/trunk/gcc/ChangeLog-2010?view=co

So I can't find when it was deprecated, it was not previously a no-op
in cygwin, and it was only removed three years ago. This means that
there could be people using -mno-cygwin option in the way that Paul
describes (although the scenario does sound a little absurd).

The msvcr90 target was added to mingw in Nov 2007 according to
http://sourceforge.net/p/mingw/mingw-org-wsl/ci/master/tree/doc/historical/mingw/ChangeLog
This is 2-3 years before the -mno-cygwin option was disabled in gcc.
However, it seems that what I really need to find is when the msvcr90
target was usable from cygwin which I am trying to do now.

Thanks again for your help,
Oscar

------------------------------------------------------------------------------
AlienVault Unified Security Management (USM) platform delivers complete
security visibility with the essential security capabilities. Easily and
efficiently configure, manage, and operate all of your security controls
from a single console and one unified framework. Download a free trial.
http://p.sf.net/sfu/alienvault_d2d
_______________________________________________
MinGW-users mailing list
MinGW-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org

This list observes the Etiquette found at
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same. Disregard for the list etiquette may cause your account to be moderated.

Re: Fixing mingw support in Python's distutils

Earnie Boyd — 2013-05-20T13:54:19

No!!! The -mno-cygwin abomination is dead.  If you want to build a
native Python using Cygwin you would do it the cross compiler way and
state the --host you're configuring for.  Python's distutil needs to
remove the -mno-cygwin option.


If they do they'll need to use the cross compilers.

Re: Fixing mingw support in Python's distutils

Oscar Benjamin — 2013-05-20T13:33:03

Oh, okay. That seems a plausible explanation for the origin of this bug.


I guess I'll still need go check what cygwin did with the option then.

Thanks to everyone here. I think I have all the information that is
needed concerning mingw.


Oscar

------------------------------------------------------------------------------
AlienVault Unified Security Management (USM) platform delivers complete
security visibility with the essential security capabilities. Easily and
efficiently configure, manage, and operate all of your security controls
from a single console and one unified framework. Download a free trial.
http://p.sf.net/sfu/alienvault_d2d
_______________________________________________
MinGW-users mailing list
MinGW-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org

This list observes the Etiquette found at 
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same.  Disregard for the list etiquette may cause your account to be moderated.

_______________________________________________
You may change your MinGW Account Options or unsubscribe at:
https://lists.sourceforge.net/lists/listinfo/mingw-users
Also: mailto:mingw-users-request-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org?subject=unsubscribe

Re: Fixing mingw support in Python's distutils

Oscar Benjamin — 2013-05-20T13:25:54

Thanks for this. That's what I wanted to know. I'll go look there.


Oscar

------------------------------------------------------------------------------
AlienVault Unified Security Management (USM) platform delivers complete
security visibility with the essential security capabilities. Easily and
efficiently configure, manage, and operate all of your security controls
from a single console and one unified framework. Download a free trial.
http://p.sf.net/sfu/alienvault_d2d
_______________________________________________
MinGW-users mailing list
MinGW-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org

This list observes the Etiquette found at 
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same.  Disregard for the list etiquette may cause your account to be moderated.

_______________________________________________
You may change your MinGW Account Options or unsubscribe at:
https://lists.sourceforge.net/lists/listinfo/mingw-users
Also: mailto:mingw-users-request-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org?subject=unsubscribe

Re: Fixing mingw support in Python's distutils

Oscar Benjamin — 2013-05-20T13:24:07

On 20 May 2013 13:30, Keith Marshall
<keithmarshall-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org> wrote:

Okay, thanks. I guess given your comments below this is unnecessary anyway.

Brilliant.

Ah, okay.

Perfect. Thanks for confirming this.

Sorry I'm unfamiliar with the way that sourceforge hosts things and
also unsure exactly which project's changelog I should be looking at.
The link you posted was the one I was after as it shows where the
msvcr90.dll target was added.

Thanks,
Oscar

This list observes the Etiquette found at
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same. Disregard for the list etiquette may cause your account to be moderated.

Re: Fixing mingw support in Python's distutils

Paul Moore — 2013-05-20T13:13:19

I think that the issue for Python (and if true, this is OT for the mingw
list, obviously, I only post here to close the loop for people following
the thread here) is that the distutils support for "building Python
extensions using mingw" did not have a very clear picture of what
constituted the mingw compiler and what constituted the cygwin one. (I may
be wrong, as I wasn't around when the code was written, but that's how it
looks to me). Keith alluded to the confusing cygwin situation earlier in
the thread, so I guess you're aware of how people can get things muddled :-)

So building an extension using --compiler=mingw in Python could pick up a
cygwin gcc if that was on PATH, and this will work as long as -mno-cygwin
is passed on the command line. But it won't work (it will build a DLL with
a dependency on the cygwin DLL) if -mno-cygwin is omitted. I'd argue that
people should just install and use mingw rather than cygwin, but that may
not be what everyone does in practice.

The real problem here is that no-one knows if people actually try to build
(native windows) Python extensions by installing Cygwin and using distutils
with Cygwin's gcc on PATH. I suspect that some do, but they may not have
been able to do so successfully for some years because of the runtime
compatibility issues. That's essentially the OP's question, but maybe it
needs directing at the cygwin folks.

This list observes the Etiquette found at
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same. Disregard for the list etiquette may cause your account to be moderated.

Re: All symbols exported from shared library?

Earnie Boyd — 2013-05-20T12:57:44

It is documented already in the binutils documentation.

Re: Fixing mingw support in Python's distutils

Keith Marshall — 2013-05-20T12:52:11


Nope.  It's mingwrt which provides support for linking to MSVCR90.DLL.
I'd previously referred him to the ChangeLog for that; he was asking
where it might be found.

Re: Fixing mingw support in Python's distutils

Earnie Boyd — 2013-05-20T12:50:59

There is no need to confirm if removing -mno-cygwin will break
anything, we can assure you that it should not at least as far as
MinGW GCC is concerned.  We do not know if Python did anything special
because of it but I would doubt it.

As for support of when it was removed, you'll need to go look at the
http://gcc.gnu.org ChangeLog to see if you can find it.  For Cygwin it
was a decision made for the 1.7.x release because it became a
nightmare for them to support.  It was much easier for them to
actually use a cross compiler method.

Re: Fixing mingw support in Python's distutils

Earnie Boyd — 2013-05-20T12:44:13

I think he meant for GCC.


mingw-get source mingw32-gcc


For the GCC repository you would need to go look at http://gcc.gnu.org.

Re: [?bug] gl_argv.gl_magic is not initialized when accessed

Sergey Martynenko — 2013-05-20T12:32:38

How to add message attached to the wanted thread ?

Re: Fixing mingw support in Python's distutils

Keith Marshall — 2013-05-20T12:30:43

The sources for *all* previous MinGW releases are available from SF, but
you may need to search the directory trees on one of their mirror sites
to find them; they aren't readily visible on the browseable download
pages.

The option was only ever meaningful for *cygwin* native GCC; it was a
nasty kludge they implemented to hide the mechanics of cross-compiling
from their users, while actually invoking mingw32 GCC to cross compile.
Why would native mingw32 GCC have needed such a kludge?

BTW, your earlier allusion to MinGW having forked from cygwin is flawed;
MinGW never did fork from cygwin, (other than in the creation of MSYS);
the only reason mingw32 GCC accepted -mno-cygwin was because the cygwin
folks had it adopted upstream, as a standard option for WIN32 targets.

CPython's distutils mixes up the code for cygwin and mingw a

This makes no sense whatsoever; -mno-cygwin is only meaningful for
*cygwin*, to force its native GCC to redirect its activity so as to
behave as a wrapper for a mingw32 cross-GCC.

BTW where is the changelog ...

<sigh> I shouldn't need to say this; you can find it in the source
tarball for the current MinGW runtime (mingwrt) release, which *is*
available from our SF download pages, (and visible there).
Alternatively, you may just:

mingw-get source mingw32-mingwrt

to download it via mingw-get, or:

mingw-get source mingw32-mingwrt --print-uri

to see the download reference.

... and can it be viewed from the web?

Yes.

Since we stopped hosting alongside cygwin, and merged mingwrt and w32api
into a common Windows System Libraries package, it has been moved to the
doc/historical tree of our WSL git repository:
https://sourceforge.net/p/mingw/mingw-org-wsl/ci/master/tree/doc/historical/mingw/ChangeLog

Re: [?bug] gl_argv.gl_magic is not initialized when accessed

Sergey Martynenko — 2013-05-20T12:20:05

All worked, Thank.

Arise another question.

when I define _CRT_glob, why it not conflict (not "multiple definition"), with
defined symbol "__CRT_glob" by the libmingw32.a ?

What mean "This file is implicitly linked" ?

First thought was, linker ends up his work, when all symbols are resolved.
And remaining files, specified for link, not viewed.

But, when define "__CRT_glob" in my code, and declare knowingly unresolved some symbol,
for example "zzz", it must force linker to go on all, including last libmingw32.a.
"Multiple definition" not happened, as I expect. Oddly.

where to read about this technics "implicitly linked"

--
Sergey Martynenko
spam_hole< at >...
Russia, Sochi
------------------------------------------------------------------------------
AlienVault Unified Security Management (USM) platform delivers complete
security visibility with the essential security capabilities. Easily and
efficiently configure, manage, and operate all of your security controls
from a single console and one unified framework. Download a free trial.
http://p.sf.net/sfu/alienvault_d2d
_______________________________________________
MinGW-users mailing list
MinGW-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org

This list observes the Etiquette found at
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same. Disregard for the list etiquette may cause your account to be moderated.

Re: Fixing mingw support in Python's distutils

Oscar Benjamin — 2013-05-20T11:35:52

On 20 May 2013 09:50, Keith Marshall
<keithmarshall-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org> wrote:

Ah, I wondered if that would be the case.

Well this is better than I thought. If the '-mno-cygwin' option was
*never* meaningful for mingw then this is a very simple problem. I
wonder why this wasn't spotted before. Is there a way for me to
confirm this by e.g. having a link to the source of an old revision of
mingw?

If the option was never meaningful for mingw then I think that
whatever cygwin were doing with it is thankfully irrelevant for this
problem. CPython's distutils mixes up the code for cygwin and mingw a
little but the '-mno-cygwin' option is only used for mingw:
http://hg.python.org/cpython/file/42dda22a6f8c/Lib/distutils/cygwinccompiler.py#l274

So that would probably be before the option was removed. Perhaps the
msvcr90.dll question is not so helpful for this.

BTW where is the changelog and can it be viewed from the web? I'm
having trouble locating it.

Thanks,
Oscar

This list observes the Etiquette found at
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same. Disregard for the list etiquette may cause your account to be moderated.

Re: Fixing mingw support in Python's distutils

Oscar Benjamin — 2013-05-20T11:23:11

Thanks.

Is there a web accessible changelog or similar that I could use to confirm this?


Oscar

------------------------------------------------------------------------------
AlienVault Unified Security Management (USM) platform delivers complete
security visibility with the essential security capabilities. Easily and
efficiently configure, manage, and operate all of your security controls
from a single console and one unified framework. Download a free trial.
http://p.sf.net/sfu/alienvault_d2d
_______________________________________________
MinGW-users mailing list
MinGW-users-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org

This list observes the Etiquette found at 
http://www.mingw.org/Mailing_Lists.
We ask that you be polite and do the same.  Disregard for the list etiquette may cause your account to be moderated.

_______________________________________________
You may change your MinGW Account Options or unsubscribe at:
https://lists.sourceforge.net/lists/listinfo/mingw-users
Also: mailto:mingw-users-request-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f< at >public.gmane.org?subject=unsubscribe