[Bug 510949] New: upgrade to gcc 4.4.0 proper and mingw upstream

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Summary: upgrade to gcc 4.4.0 proper and mingw upstream

https://bugzilla.redhat.com/show_bug.cgi?id=510949

Summary: upgrade to gcc 4.4.0 proper and mingw upstream
           Product: Fedora
           Version: rawhide
          Platform: All
        OS/Version: Linux
            Status: NEW
          Severity: low
          Priority: low
         Component: mingw32-gcc
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]
         QAContact: [e-mail]
                CC: [e-mail], [e-mail],
                    [e-mail]
    Classification: Fedora

Description of problem:
gcc 4.4 was released on 21st April, a little later than feature fedora 11
freeze; and the mingw people has also released a mingw patch set, with some
mingw specific changes a few weeks ago... wouldn't it be nice to upgrade and
synchronization with upstream (gcc or mingw)?

I also noted that the fedora shipped compiler uses sjlj exception, apparently
dwarf2 is the supported model...

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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Levente Farkas  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

--- Comment #1 from Levente Farkas   2009-07-13 03:42:25 EDT ---
see the fedora-mingw list for exception handling discussion.

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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--- Comment #2 from Hin-Tak Leung   2009-07-15 16:22:30 EDT ---
Created an attachment (id=353901)
 --> (https://bugzilla.redhat.com/attachment.cgi?id=353901)
diff of my spec vs the fefora -0.7 spec file

As a proof of concept, I have unpacked the fedora
mingw32-gcc-4.4.0-0.7.fc11.src.rpm and modified it to use the upstream release
tar ball, plus all 13 of mingw patches.

5 of the fedora patches didn't apply (patch 0,24,25,26,27):
gcc44-hack.patch
gcc44-atom.patch
gcc44-pr39226.patch
gcc44-power7.patch
gcc44-power7-2.patch
I think both patch 24 and 25 was incorporated upstream and can be dropped, and
26,27 are partially incorporated upstream and need some work; not sure about
the purpose of patch 0.

Out of the 13 mingw patches from gcc-4.4.0-mingw32-src-2.tar.gz (from mingw),
two has slight problem: "gcc-4.4.0-20090418-dllimport-libstdc++.patch" has some
typo itself which is reported upstream (see my recent post to mingw-devel
mailing list),  "gcc-4.4.0-20090418-libjava_s.patch" duplicates one chunk which
is also in the fedora patch. Both are trivial problems and quite easy to fix
for anybody who knows a bit of C.

I also noticed that the new default is to build the language-specific
libfortran.dll, etc, but there is no sjlj dll (no exception?), so I added the
disable-shared (to stop the generation of libfortran, libobjc, etc) and
--with-dwarf2 .

I hope somebody examine the 5 failed fedora patches (maybe take a look at the
native compiler src rpm? it seems to be newer than mingw32-gcc) and also merges
the mingw patches in properly.

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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--- Comment #3 from Hin-Tak Leung   2009-07-15 16:56:05 EDT ---
(In reply to comment #1)
> see the fedora-mingw list for exception handling discussion.

I only found a thread in Nov 2008. The situation has likely changed since
(particularly with the release of gcc 4.4 from gnu.gcc , and also a mingw gcc
4.4 release plus patch set). Maybe somebody in fedora should re-visit this
issue.

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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--- Comment #4 from Hin-Tak Leung   2009-07-15 17:40:12 EDT ---
Hmm, it looks like the fedora patch set is simply the same set from the native
compiler around the same time (except dropping fastjar-0.97*). and I see some
mention of strange relationship between fedora and gcc... but in any case, I
reckon some of the 13 upstream mingw patches could be incoporated?

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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Hin-Tak Leung  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
 Attachment #353901|0                           |1
        is obsolete|                            |

--- Comment #5 from Hin-Tak Leung   2009-07-16 14:51:29 EDT ---
Created an attachment (id=354033)
 --> (https://bugzilla.redhat.com/attachment.cgi?id=354033)
tarball of mods for latest gcc from koji

This is a tarball of a modified mingw32-gcc specs file to use the latest native
gcc from koji (4.4.0-13), and all the upstream mingw patches.

3 of the 13 upstream patches need some adaptation (so attached). Two of the 3, 
gcc-4.4.0-20090418-libjava_s.patch gcc-4.4.0-20090418-ada-hang.patch look like
they are partly in fedora native gcc anyway; the 3rd one is slightly broken and
reported upstream. The result seems to have build libgfortran.dll, etc extra
compared to old.

On a different matter, the upstream mingw gcc release notes have these
paragraphs:
===========
- Zero cost exceptions: New exception model Dwarf only has performance
  penalty when being thrown.  The old model, SJLJ, is no longer
  available.

===========
- Dynamic linking with libgcc_s_dw2-1.dll

Dynamic linking with libgcc_s_dw2-1.dll is necessary to throw
exceptions between different modules, such as between two DLLs or a
DLL and an EXE.  Consequently, it is the default for all languages
other than C.  To disable this dynamic linking, use -static-libgcc.
To enable this dynamic linking in C, use -shared-libgcc.
===========

I haven't been able to get a dw2-1.dll at all, and some experiment
(disable-shared) results in broken dependences - a few packages
mingw32-gettext/boost/pthread have explicit dependency on the sjlj-1.dll.

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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--- Comment #6 from Levente Farkas   2009-07-16 14:59:28 EDT ---
it's not that simple. since we build all current dlls with sjlj we've to
rebuild all mingw packages and none of the previous dlls can be linked with
current ones:-(

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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--- Comment #7 from Hin-Tak Leung   2009-07-16 17:07:08 EDT ---
(In reply to comment #6)
> it's not that simple. since we build all current dlls with sjlj we've to
> rebuild all mingw packages and none of the previous dlls can be linked with
> current ones:-(

Bring the package up to date source code-wise and incoporating the 13 upstream
mingw patches, and switching the exception model are two different issues - the
former is easy (and I already did it with the tarball I posted). The latter I
know is a bit tricky.

OTOH, I have 39 of mingw32-* packages on my system and only 4 have a sjlj-1.dll
dependence (from "rpm -q --whatrequires 'mingw32(libgcc_s_sjlj-1.dll)'") -
mostly libraries written in c++ or one with a non-c binding. A majority of
mingw32 packages currently available from fedora 11 are not affected if a
switch is made - you just need to rebuild *some* packages, and a minority, I
think.

I think a switch should be made *eventually*, especially now that the mingw
project itself has switched to dw2. Maybe for the f12 time frame? - should I
file that separately?

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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Kalev Lember  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |CLOSED
                 CC|                            |[e-mail]
   Fixed In Version|                            |4.4.1-1.fc12
         Resolution|                            |NEXTRELEASE

--- Comment #8 from Kalev Lember   2009-08-26 18:45:48 EDT ---
I have now updated mingw32-gcc package in rawhide to 4.4.1 snapshot to match
the version of the native gcc package. The update was also discussed on
fedora-mingw mailing list [1].

I'm closing this bug as fixed. Please open another bug for changing the
exception model. It's a change that should be done early in Fedora 13 cycle.
For Fedora 12, however, the exception model most likely remains sjlj.

[1] 
http://lists.fedoraproject.org/pipermail/fedora-mingw/2009-August/001997.htm...

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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--- Comment #9 from Hin-Tak Leung   2009-08-28 12:45:33 EDT ---
mingw upstreams have a bundle of some 12-13 patches:

http://sourceforge.net/projects/mingw/files/GCC%20Version%204/Current%20Rele...

consider incorporating them?

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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Erik van Pienbroek  changed:

What    |Removed                     |Added
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                 CC|                            |[e-mail]

--- Comment #10 from Erik van Pienbroek   2009-08-30 06:32:27 EDT ---
(In reply to comment #9)
> mingw upstreams have a bundle of some 12-13 patches:
>
> http://sourceforge.net/projects/mingw/files/GCC%20Version%204/Current%20Rele...
>
> consider incorporating them?

Yes they were considered. See
http://lists.fedoraproject.org/pipermail/fedora-mingw/2009-August/001997.htm...
for the discussion. After this mailing list discussion, we continued on IRC
(FreeNode, #fedora-mingw). It wasn't clear to us whether it was safe to apply
these patches as none of us is familiar enough with the GCC internals. Next to
this we're using a different exception model right now (which is planned to be
changed for Fedora 13). We all agreed that if the patches are really necessary
then they should be upstreamed by the MinGW folks anyway. So in the end we
refrained from applying the MinGW patches (at least for now).

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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Kevin Kofler  changed:

What    |Removed                     |Added
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                 CC|                            |[e-mail]

--- Comment #11 from Kevin Kofler   2009-08-30 17:07:26 EDT ---
IMHO fedora-mingw's GCC should match the upstream MinGW code (including
patches) and exception handling, to be binary compatible with things like the
kdewin binary packages. (Right now, the old binaries built with MinGW GCC 3.4
are probably compatible, but those are going away at kdewin and probably most
other upstreams.)

I'm also familiar to some extent with the GCC internals, due to my work in the
TIGCC project. I could have a look at those MinGW patches. But I don't see them
being "unsafe" at all.

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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--- Comment #12 from Kalev Lember   2009-09-01 08:25:15 EDT ---
Kevin, that would be great. Thanks.

I did a quick review of upstream mingw patches and posted the results [1] in
the fedora-mingw list. Could we continue the discussion in there? Mr. Leung
might also want to subscribe to the fedora-mingw list.

I think we should switch the exception model to dwarf2 early in F-13 cycle, and
this is the time when some of the mingw patches might come handy. If you take a
look at [1], you'll see that right now most of the patches aren't very useful
because they are either related to languages we don't build (ada, gcj) or
contain fixes to dwarf exceptions.

[1]
http://lists.fedoraproject.org/pipermail/fedora-mingw/2009-August/002007.htm...

[Bug 510949] upgrade to gcc 4.4.0 proper and mingw upstream

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--- Comment #13 from Kevin Kofler  2010-05-24 00:17:43 EDT ---
I thought it was decided to ship F13 with a MinGW toolchain binary-compatible
with upstream MinGW? So why are we still shipping a GCC with SJLJ expections
and without MinGW patches in F13 and even F14 Rawhide? :-(