bug#1191: How to contribute back changes for Emacs on Solaris

[Dan Nicolaescu <dann@ics.uci.edu>]

Ali Bahrami <ali_gnu@emvision.com> writes:

  > Dan Nicolaescu wrote:
  > > Ali Bahrami <ali_gnu@emvision.com> writes:
  > >
  > >   > This message is a follow up to one I sent to emacs-devel
  > >   > last July:
  > >   >   >
  > > http://lists.gnu.org/archive/html/emacs-devel/2008-07/msg00070.html
  > >   >   > The question had to do with why emacs wasn't using dldump()
  > >   > to produce the dumped executable under Solaris. It had been using it
  > >   > up until 2002, at which point it was commented out, and it wasn't
  > >   > clear why. No one knew the reason, and the consensus was "try it and see".
  > >   >   > Since then, I've done some work to integrate emacs with
  > >   > OpenSolaris as a standard package. I turned on dldump(),
  > >   > and have been using the emacs binaries built with it daily
  > >   > since July without issue.
  > >   >   > So now, I have some things I'd like to send back up stream
  > >   > and get integrated into the emacs distribution:
  > >   >   > 	- Man pages for things installed to /usr/bin that
  > > didn't
  > >   > 	  already have a manpage:
  > >   > 		b2m.1
  > >   > 		ebrowse.1
  > >   > 		grep-changelog.1
  > >   > 		rcs-checkin.1
  > >   > 	- Small changes to config.guess and configure to properly
  > >   > 	  detect amd64 hardware running Solaris.
  > >   > 	- Use dldump() instead of the generic ELF dump code
  > >   > 	  under Solaris.
  > >   > 	- Use the system malloc under Solaris (at least with
  > >   > 	  amd64, emacs crashes without this).
  > >   >   > The manpages can be viewed at:
  > >   >   >
  > > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/emacs/augment/man/man1/b2m.1
  > >   > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/emacs/augment/man/man1/ebrowse.1
  > >   > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/emacs/augment/man/man1/grep-changelog.1
  > >   > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/emacs/augment/man/man1/rcs-checkin.1
  > >
  > > Hopefully someone else can address these changes, I'll address the rest.
  > >
  > >   > and the patches at:
  > >   >   >
  > > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/emacs/augment/patch/config.guess.patch
  > >
  > > Please send this one to config-patches@gnu.org.
  > > We don't modify this file directly in emacs, it gets updated from time
  > > to time from:
  > > http://savannah.gnu.org/cgi-bin/viewcvs/*checkout*/config/config/config.guess
  > >
  > >   > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/emacs/augment/patch/configure.patch
  > >
  > > This one is fine, but it depends on the previous one being installed by
  > > the config.guess maintainers.
  > > BTW, do you know anything about emacs running on  powerpc*-*-solaris2*
  > > or  rs6000-*-solaris2* ? configure.in mentions them.
  > >
  > >   > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/emacs/augment/patch/dldump.patch
  > >
  > > Last time when you posted this you said you were going to test it on
  > > multiple Solaris versions.  Have you managed to do that?  This is also
  > > valid for the next patch.
  > >
  > >   > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/emacs/augment/patch/sysmalloc.patch
  > >   >   > The patches are for emacs 22.1. I've examined 22.3, and the
  > >   > changes are applicable there as well. If 22.1 diffs are OK,
  > >   > that's easiest for me, but if not, then please let me know what
  > >   > I need to supply. These diffs are all very short, affecting a
  > >   > small number of lines in each file.
  > >
  > > AFAIK the 22.x branch is closed, there will not be any more releases
  > > from that branch.  But we could install your changes on HEAD.
  > >
  > > Thanks
  > >
  > >         --dan
  > 
  > Hi Dan,
  > 
  >    I will send the config.guess patch to config-patches@gnu.org today.
  > In the meantime, the change to configure should be safe to make immediately.

I'd rather wait and check in both of them together.

  > I'm only concerned about getting these changes into HEAD. My patches are
  > for 22.1, but only because that's the version I used for this work. So
  > that would be great. If you can use these old patches as a basis for making
  > the necessary changes (which are small) to HEAD, then that would be a big
  > time saver for me, and much appreciated. If you need specific patches against
  > HEAD, then point me at it and I'll put some together.

The changes are tiny, so the base version does not make any difference
in this particular case.

  > I only know a little about emacs on the power architecture: Sun funded
  > a port during the 90's. As a point of irrelevant trivia, it was a little endian
  > system, and not big endian as one might expect. For reasons that are lost
  > in time, the port was completed, and a few pre-releases were made, but it never
  > shipped as a standard product, wasn't updated with the main branch, and quickly
  > faded away. My only quess is that powerpc*-*-solaris2* and rs6000-*-solaris2*
  > (the rs6000 also being a Power architecture system) date from this port, and
  > have probably never had more than a small handful of users --- probably none for
  > a decade or so.

Thank you for the detailed info, then we can deprecate these ports for
the next release.

  > About testing different Solaris versions, I remember the question being asked.
  > I thought I replied at the time, but can't be sure. In any event, the answer is
  > no. My interest is with the modern Solaris, which is OpenSolaris, and Solaris 10.
  > That's all I've tested, and I apologize for not having said that
  > directly. There are several reasons:
  > 
  > 	- Maximizing the value of the time I spend on this project
  > 	- No evidence of an actual problem with dldump for older Solaris,
  > 	  including the fact that xemacs has apparently been using it
  > 	  all along
  > 	- The fact that the generic ELF dump code does work, and can be
  > 	  used for those old releases. It isn't as nice as the dldump'd
  > 	  version, but the resulting executables would run as well as they
  > 	  ever did. Hence, there's an easy fallback if something did come up.
  > 
  > None of which, I admit, is actual testing. I feel that the risk of switching
  > the old versions to dldump() is minimal. However, if you feel more comfortable
  > applying this change such that it only applies to Solaris 10 and newer, that
  > would also be fine.

I don't feel comfortable doing these changes without any testing at
all.  In that case, the best would be to add a new file
emacs/src/s/sol2-10.h that includes sol2-6.h and also contains your
changes.  
Then change configure.in to use that new file for Solaris 10+.