arch (revision control system)

arch (revision control system)

[Tom Lord]

I've made the first public release of `arch', a new revision control
system. You can find it at:

	http://www.regexps.com

The user's guide is on-line, as is a simple repository browser for the
change history.  There's a read-only copy of arch's self-hosted
repository there too.  (Please let me know if the web pages give you
troubles on your particular browser -- this is the first time I've
tried using tables and colors so heavily.)

arch has some features that I think could help the GCC project.
Especially:

	+ distributed repositories

	  Contributors who lack write access to the main repository
	  can form branches in repositories on their own FTP sites.
	  That simplifies the job of those contributors (since
	  they can perform merges directly from the main line of
	  development) and simplifies the job of patch reviewers
	  (since they can check out contributors' revisions directly,
	  and use arch's change-set->HTML tool to review the proposed
	  changes).

	  
	+ star topology branches

	  arch has high-level support for a main-line of development,
	  with surrounding branches (the graph of these has a star
	  topology).  The high-level support is the command
	  "star-merge" which intelligently merges back and forth 
	  between the main line and surrounding branches (see the 
	  user's guide for a more complete description).

	  This feature makes it convenient for each patch reviewer or
	  major contributor to buffer and test changes to the
	  main-line in their own, long-lived branch.  (Yes, this is
	  possible in CVS, but far less convenient.)

	  
	+ automatic ChangeLog maintenance

	  Each (whole-tree) commit in arch has a log message.  arch
	  can convert those log messages into ChangeLogs, including
	  accurate records of all files changed.  I've found it 
	  convenient to keep a separate ChangeLog for the main trunk
	  and each major branch;  arch has a ChangeLog->HTML tool
	  that links brief summary logs, in the trunk ChangeLog, 
	  to detailed logs in the branch logs.


See the =TODO file (linked from www.regexps.com) to get a sense of
what I think the delta is from arch's current state, to its being
ready to deploy for a project as large, active, and mission critical
as GCC.  If you like the idea of using arch for GCC, look for a way to
pitch in.

-t