Moving GDB sources to subversion?

Moving GDB sources to subversion?

[Joel Brobecker]

Hello,

I think GCC is getting ready to move to subversion as the revision
control system. Is there any similar plan for GDB?

Thanks,
-- 
Joel

Re: Moving GDB sources to subversion?

[Simon Richter]

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Hi,

Joel Brobecker schrieb:

> I think GCC is getting ready to move to subversion as the revision
> control system. Is there any similar plan for GDB?

At present, there appears to be a SCM war going on, with everyone trying
to pull as many projects towards their side as possible. As a cogito
fan, I'm no exception to that :-). I personally don't like svn for the
simple reason that it provides no substantial improvement over CVS. It
is still centrally organized and works best if only a core group who
knows the system by heart commits patches, in case they need to be
merged; at the same time, it has a very informal notion of branches and
tags, which is a great disadvantage in my opinion.

I've learned to live with CVS by using a cronjob that incrementally
imports new commits into my working tree, which happens to be git-based;
a similar thing could be done to create a SVN repository that tracked
CVS and allowed people to use svn if happens to be their preferred tool.
Using svn for the master tree would make this difficult because of the
aforementioned informality on branches and tags; an import script would
be forced to use heuristics to properly determine them.

   Simon

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Re: Moving GDB sources to subversion?

[Mark Kettenis]

> Date: Fri, 28 Oct 2005 15:22:53 -0700
> From: Joel Brobecker <brobecker@adacore.com>
> 
> Hello,
> 
> I think GCC is getting ready to move to subversion as the revision
> control system. Is there any similar plan for GDB?

Why should we?

Mark

Re: Moving GDB sources to subversion?

[Joel Brobecker]

> > I think GCC is getting ready to move to subversion as the revision
> > control system. Is there any similar plan for GDB?
> 
> Why should we?

I wasn't implying that we should. I haven't seen any discussion about
this (but maybe I missed them). However, I have heard rumors that GCC
*is* going to move to svn. I think GCC and GDB have been in the same
physical repository so far (src?), so I was afraid that a change for
GCC would necessarily impact GDB.

-- 
Joel

Re: Moving GDB sources to subversion?

[Andreas Tobler]

Joel Brobecker wrote:
>>>I think GCC is getting ready to move to subversion as the revision
>>>control system. Is there any similar plan for GDB?
>>
>>Why should we?
> 
> 
> I wasn't implying that we should. I haven't seen any discussion about
> this (but maybe I missed them). However, I have heard rumors that GCC
> *is* going to move to svn. I think GCC and GDB have been in the same
> physical repository so far (src?), so I was afraid that a change for
> GCC would necessarily impact GDB.
> 
gcc _has_ moved to svn today. Means it is active from today. svn.

Andreas

Re: Moving GDB sources to subversion?

[Ian Lance Taylor]

Joel Brobecker <brobecker@adacore.com> writes:

> > > I think GCC is getting ready to move to subversion as the revision
> > > control system. Is there any similar plan for GDB?
> > 
> > Why should we?
> 
> I wasn't implying that we should. I haven't seen any discussion about
> this (but maybe I missed them). However, I have heard rumors that GCC
> *is* going to move to svn. I think GCC and GDB have been in the same
> physical repository so far (src?), so I was afraid that a change for
> GCC would necessarily impact GDB.

gcc has moved to subversion.  The conversion finished today.

This does not affect gdb.  At present gdb, binutils, newlib, and
cygwin share a single CVS repository.  gcc is in a subversion
repository.

This does affect anybody using the uberbaum pseudo-repository; if you
don't know what that is, don't ask.

It would be simpler for the sourceware.org overseers (including
myself) if every project converted to subversion.  And subversion does
have some advantages over CVS.

But really each project is going to have to decide for itself whether
to switch or not.

(If you want to switch to something other than CVS or subversion, you
will have to be prepared to convince the overseers to do whatever
management is required by whatever new system is chosen.  Daniel
Berlin went through that process for subversion for gcc.)

Hope this helps.

Ian

Re: Moving GDB sources to subversion?

[Daniel Jacobowitz]

On Sat, Oct 29, 2005 at 12:56:02AM +0200, Mark Kettenis wrote:
> > Date: Fri, 28 Oct 2005 15:22:53 -0700
> > From: Joel Brobecker <brobecker@adacore.com>
> > 
> > Hello,
> > 
> > I think GCC is getting ready to move to subversion as the revision
> > control system. Is there any similar plan for GDB?
> 
> Why should we?

I'd rather not rehash the months of discussion from the GCC list about
this :-)

From my point of view:

  - It's similar enough to CVS to not be terribly disruptive.
  - It's generally more robust than CVS.
  - Atomic changesets are a nice thing to have nowadays.
  - Branches are cheaper, and merges are easier.
  - Tags don't lock the repository for half an hour.
  - Oh, and staying consistent for those of us who work on both
    GCC and GDB.

I've used it, I like it, I think it's a mild improvement rather than a
revolution.  I'm not violent about it.

Someone needs to think about how the src repository would work, though. 
Checking out just part of a subversion repository is harder than it was
in CVS.

-- 
Daniel Jacobowitz
CodeSourcery, LLC

Re: Moving GDB sources to subversion?

[Joel Brobecker]

> I'd rather not rehash the months of discussion from the GCC list about
> this :-)
> 
> >From my point of view:

It is not my intention to push in any direction. I'll be happy to move
to svn if most of us think it's better, but I'm also happy to stick to
CVS.

-- 
Joel

Re: Moving GDB sources to subversion?

[Mark Kettenis]

> Date: Fri, 28 Oct 2005 19:14:30 -0400
> From: Daniel Jacobowitz <drow@false.org>
> 
> On Sat, Oct 29, 2005 at 12:56:02AM +0200, Mark Kettenis wrote:
> > 
> > Why should we?
> 
> I'd rather not rehash the months of discussion from the GCC list about
> this :-)

The we're on the same wavelength.  Let's put our effort into improving
GDB; not in changing our infrastructure, let alone discussions about
our infrastructure.

Mark

Re: Moving GDB sources to subversion?

[Nick Roberts]

 > The we're on the same wavelength.  Let's put our effort into improving
 > GDB; not in changing our infrastructure, let alone discussions about
 > our infrastructure.

Following that argument, GDB would still be distributed by tape.  We can
assume that GCC developers have made a sound technical decision.  We should
focus on how GDB development differs from that of GCC and whether that
difference impacts on the choice of version control used.

Nick

Re: Moving GDB sources to subversion?

[Christopher Faylor]

On Fri, Oct 28, 2005 at 04:25:53PM -0700, Joel Brobecker wrote:
>>I'd rather not rehash the months of discussion from the GCC list about
>>this :-)
>>
>>From my point of view:
>
>It is not my intention to push in any direction.  I'll be happy to move
>to svn if most of us think it's better, but I'm also happy to stick to
>CVS.

As Ian said, from the point of view of the people who maintain sourceware,
it would be easier if everything (or at least every substantial project)
moved to using subversion.  The benefits have been outlined already.

FWIW, we'll probably move cygwin to subversion as soon as the gcc dust
has settled.

cgf

Re: Moving GDB sources to subversion?

[H. J. Lu]

I'd like to see gdb move to bugzilla before subversion.


H.J.
On Fri, Oct 28, 2005 at 04:08:34PM -0700, Ian Lance Taylor wrote:
> Joel Brobecker <brobecker@adacore.com> writes:
> 
> > > > I think GCC is getting ready to move to subversion as the revision
> > > > control system. Is there any similar plan for GDB?
> > > 
> > > Why should we?
> > 
> > I wasn't implying that we should. I haven't seen any discussion about
> > this (but maybe I missed them). However, I have heard rumors that GCC
> > *is* going to move to svn. I think GCC and GDB have been in the same
> > physical repository so far (src?), so I was afraid that a change for
> > GCC would necessarily impact GDB.
> 
> gcc has moved to subversion.  The conversion finished today.
> 
> This does not affect gdb.  At present gdb, binutils, newlib, and
> cygwin share a single CVS repository.  gcc is in a subversion
> repository.
> 
> This does affect anybody using the uberbaum pseudo-repository; if you
> don't know what that is, don't ask.
> 
> It would be simpler for the sourceware.org overseers (including
> myself) if every project converted to subversion.  And subversion does
> have some advantages over CVS.
> 
> But really each project is going to have to decide for itself whether
> to switch or not.
> 
> (If you want to switch to something other than CVS or subversion, you
> will have to be prepared to convince the overseers to do whatever
> management is required by whatever new system is chosen.  Daniel
> Berlin went through that process for subversion for gcc.)
> 
> Hope this helps.
> 
> Ian

Re: Moving GDB sources to subversion?

[Stan Shebs]

Joel Brobecker wrote:

>Hello,
>
>I think GCC is getting ready to move to subversion as the revision
>control system. Is there any similar plan for GDB?
>
We've been waiting for your writeup. :-)

But seriously, in my limited use of subversion so far, I've been
pleased with it, and it seems worth converting src at some point.
Meanwhile, we can pass the popcorn while watching GCC change over...

Stan

Re: Moving GDB sources to subversion?

[Eli Zaretskii]

> From: Nick Roberts <nickrob@snap.net.nz>
> Date: Sat, 29 Oct 2005 12:56:30 +1300
> Cc: drow@false.org, brobecker@adacore.com, gdb@sources.redhat.com
> 
> We can assume that GCC developers have made a sound technical decision.

Yes, we can assume that.  But no one said that there's only one sound
technical decision.  I'm sure there were downsides to that decision
even in the context of the GCC project (as opposed to a general
decision that _all_ GNU projects should adopt svn).  I'm sure that the
decision they made was influenced, at least to some degree, by the
persons who were involved in making the decision, and by their social
dynamics.

These aspects are different in the GDB case, and, of course, GDB is a
different type of project with different (albeit similar) development
and maintenance patterns and different goals.  It is quite possible
that the same set of considerations as those that were discussed by
the GCC team will, in our case, lead to different conclusions and to
different decisions, that are no less sound and technical.

> We should focus on how GDB development differs from that of GCC and
> whether that difference impacts on the choice of version control
> used.

Yes, 100% agreement here.  But we could also decide not to do this
right now, and instead concentrate on development.  That would be a
sound technical decision as well.

Btw, where's the thread (or threads) in which GCC people discussed
this issue?

Re: Moving GDB sources to subversion?

[Ian Lance Taylor]

Eli Zaretskii <eliz@gnu.org> writes:

> Btw, where's the thread (or threads) in which GCC people discussed
> this issue?

Switching to something other than CVS has been discussed for a long
time.

Here are a couple of relevant threads.

http://gcc.gnu.org/ml/gcc/2004-06/msg00264.html

http://gcc.gnu.org/ml/gcc/2005-02/msg00204.html
    (the start of the thread is missing from gcc.gnu.org for some
     reason--it can be seen here:
         http://thread.gmane.org/gmane.comp.gcc.patches/84811)

Ian

Re: Moving GDB sources to subversion?

[Bob Rossi]

On Sat, Oct 29, 2005 at 12:57:02PM +0200, Eli Zaretskii wrote:
> > From: Nick Roberts <nickrob@snap.net.nz>
> > Date: Sat, 29 Oct 2005 12:56:30 +1300
> > Cc: drow@false.org, brobecker@adacore.com, gdb@sources.redhat.com
> > 
> > We can assume that GCC developers have made a sound technical decision.
> 
> Yes, we can assume that.  But no one said that there's only one sound
> technical decision.  I'm sure there were downsides to that decision
> even in the context of the GCC project (as opposed to a general
> decision that _all_ GNU projects should adopt svn).  I'm sure that the
> decision they made was influenced, at least to some degree, by the
> persons who were involved in making the decision, and by their social
> dynamics.

Definatly. For instance, look at the Linux kernel. Linus has already
said 
 "PS. Don't bother telling me about subversion." at
  http://lwn.net/Articles/130681/

Also, The Subversion Development Team wrote a letter to tell people to
stop bothering Linus about subversion.
   http://subversion.tigris.org/subversion-linus.html

I personally don't see a large difference between the Linux kernel
development and the GCC developement stratagies. With that in mind, it's
hard for me to understand why GCC *is* a good choice for subversion and
Linux *is not*.

If it was up to me, I'd rather see GDB switch to a distributed RCS. I
usually have several tree's and it takes a long time to update them all
by hitting the internet each time. Until we get a distributed RCS,
subversion definatly seems like an improvement to CVS. I'd be happy to
see the change.

Bob Rossi

Re: Moving GDB sources to subversion?

[Eli Zaretskii]

> Cc: gdb@sourceware.org
> From: Ian Lance Taylor <ian@airs.com>
> Date: 29 Oct 2005 17:11:32 -0700
> 
> Here are a couple of relevant threads.
> 
> http://gcc.gnu.org/ml/gcc/2004-06/msg00264.html
> 
> http://gcc.gnu.org/ml/gcc/2005-02/msg00204.html
>     (the start of the thread is missing from gcc.gnu.org for some
>      reason--it can be seen here:
>          http://thread.gmane.org/gmane.comp.gcc.patches/84811)

Thanks.

Re: Moving GDB sources to subversion?

[Ian Lance Taylor]

Bob Rossi <bob@brasko.net> writes:

> Definatly. For instance, look at the Linux kernel. Linus has already
> said 
>  "PS. Don't bother telling me about subversion." at
>   http://lwn.net/Articles/130681/
> 
> Also, The Subversion Development Team wrote a letter to tell people to
> stop bothering Linus about subversion.
>    http://subversion.tigris.org/subversion-linus.html
> 
> I personally don't see a large difference between the Linux kernel
> development and the GCC developement stratagies. With that in mind, it's
> hard for me to understand why GCC *is* a good choice for subversion and
> Linux *is not*.

I don't know how much people want to get into this on the gdb list,
but....

There is a big difference between Linux kernel development practices
and gcc development practices.  In Linux kernel development a number
of different people maintain large separate branches on an ongoing
basis, and there are frequent cross-merges between different branches.
Large projects are developed and maintained by independent groups of
developers, and then merged into other main trees over time.  There is
no single master repository--obviously the one that Linus controls has
some priority, but I believe that none of the major commercial Linux
distros actually make releases out of it.  As far as I know there is
no formal management of copyright issues.

For gcc, on the other hand, there is a single master repository.
Significant gcc support companies such as CodeSourcery and Red Hat
make releases directly from branches in the master repository.  In
order to get write access to the master repository, you must sign
formal copyright assignment papers with the FSF.  There are no
long-lived independent branches; the goal of all branches is to merge
into the trunk.

The upshot is that Linux requires a distributed source code control
system.  In fact, Bitkeeper was developed with an eye on what Linus
required.  gcc does not require a distributed source code control
system.  gcc might benefit from one; who knows?  We seriously
considered monotone, but at present it simply is not fast enough to
manage the gcc repository.  The same is true of arch.  We looked at
git; it presumably has the features that Linus needs, but it does not
have the features that gcc needs.

Hope this helps.

Ian

Re: Moving GDB sources to subversion?

[Daniel Jacobowitz]

On Sat, Oct 29, 2005 at 10:47:10PM -0400, Bob Rossi wrote:
> If it was up to me, I'd rather see GDB switch to a distributed RCS. I
> usually have several tree's and it takes a long time to update them all
> by hitting the internet each time. Until we get a distributed RCS,
> subversion definatly seems like an improvement to CVS. I'd be happy to
> see the change.

In addition to what Ian said, with which I completely agree, this is
not a justification for a distributed version control system.  You can
do this with cvs (rsync the repository or use cvsup) and with svn
(rsync the repository or use svk).

-- 
Daniel Jacobowitz
CodeSourcery, LLC

Re: Moving GDB sources to subversion?

[Jim Blandy]

Joel Brobecker <brobecker@adacore.com> writes:
> I think GCC is getting ready to move to subversion as the revision
> control system. Is there any similar plan for GDB?

SUBVERSION IS THE LIGHT AND THE WAY!!!  ALL WHO DENY ITS SUPREMACY
SHALL BE CAST INTO THE PIT OF ETERNAL PERDITION AND DISORDERLY
COMMAND-LINE ARGUMENTS!!!

*ahem*  "Yes, much better, thanks."

Re: Moving GDB sources to subversion?

[Daniel Jacobowitz]

On Sat, Oct 29, 2005 at 01:24:17AM +0200, Mark Kettenis wrote:
> > Date: Fri, 28 Oct 2005 19:14:30 -0400
> > From: Daniel Jacobowitz <drow@false.org>
> > 
> > On Sat, Oct 29, 2005 at 12:56:02AM +0200, Mark Kettenis wrote:
> > > 
> > > Why should we?
> > 
> > I'd rather not rehash the months of discussion from the GCC list about
> > this :-)
> 
> The we're on the same wavelength.  Let's put our effort into improving
> GDB; not in changing our infrastructure, let alone discussions about
> our infrastructure.

On the contrary, I think I could do GDB development more effectively if
it were not managed by CVS.  Subversion is a lot more useful for things
like branching, and finding bug fixes to merge them back to an old
release branch your customers are still using.  Which I waste a lot of
time on.

The only reason I'm not being more vocal about my preference to switch
is that the src repository poses certain unique challenges that GCC
didn't.  Specifically, while cvs modules are insufficient for our
needs, we've gotten used to their quirks and can cope with them. 
Subversion would have a whole different set of problems if you didn't
want to check out the whole src tree.

I don't think it's feasible for us to switch until someone has invested
some time thinking about that problem, and coming up with a better
solution than anything I've come up with so far.

-- 
Daniel Jacobowitz
CodeSourcery, LLC