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Re: Beyond GCC 3.0

Joern Rennecke wrote:

>   It has a concept
> > called an MR which is an ECMS object that keeps track of a group of
> > changes that are logically related.  (For example, all the changes for a new
> > register allocator would be on one MR.)  One file can be changed more
> > than once on the same MR.  The second great featue was given MRs A,
> > B, C, and D have been created (in that order), ECMS would let users extract
> > a copy of the code that included any combination of these changes (MRs).
> > For example, someone could get all changes for MR C, without getting
> > changes for MRs A, B, or D.  This is very useful because you can run the
> > regression tests on each MR independently, and not "approve" an MR until
> > the tests pass.
> I don't see how this differs from CVS branches.

Think of it as the difference between a tape drive (sequential access) and a
disk drive (random access).  As an example, consider code that Joe made
a change, then Jill, then Jack. In CVS your choices are to get (1) none of the
changes, (2) Joe's change, (3) Joe + Jill's changes, or (4) Joe + Jill + Jack's
changes.  In ECMS you can get the changes in any of these combinations::
1. none
2. joe
3. jill
4. jack
5. joe+jill
6. joe+jack
7. jill+jack
8 joe+jill+jack

The beauty is if Joe's changes turn out to have a bug, people can still get
Jill and Jack's changes without getting Joe's bad changes.

Brian Beuning

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