guile/HACKING

Here are some guidelines for working on the Guile source tree at GNU.

- We use CVS to manage the Guile sources.  The repository lives on
totoro.red-bean.com, in /u/src/master; you will need an account on
that machine to access the repository.  I recommend using the cvs
pserver protocol; thus, you should use the following as your CVS root:

	:pserver:USER@guile-cvs.red-bean.com:/u/src/master

Either set your CVSROOT environment variable to that, or give it as
the value of the global -d option to CVS when you check out a working
directory.

If you want to use SSH for security, set your CVS_RSH environment
variable to ssh, and then use the following as your CVS root:

	:ext:guile-cvs.red-bean.com:/u/src/master

The Guile sources live in several modules:

  - guile-core --- the interpreter, QuickThreads, and ice-9
  - guile-doc --- documentation in progress.  When complete, this will
	be incorporated into guile-core.
  - guile-tcltk --- the Guile/Tk interface
  - guile-rgx-ctax --- the Guile/Rx interface, and the ctax implementation
  - guile-scsh --- the port of SCSH to guile, talk to Gary Houston

- As for any part of Project GNU, changes to Guile should follow the
GNU coding standards.  The standards are available via anonymous FTP
from prep.ai.mit.edu, as /pub/gnu/standards/standards.texi and
make-stds.texi.

- Check Makefile.in and configure files into CVS, as well as any files
used to create them (Makefile.am, configure.in); don't check in
Makefiles or header files generated by configuration scripts.  The
general rule is that you should be able to check out a working
directory of Guile from CVS, and then type "configure" and "make".

- Make sure your changes compile and work, at least on your own
machine, before checking them into the main branch of the Guile
repository.  If you really need to check in untested changes, make a
branch.

- When you make a user-visible change (i.e. one that should be
documented, and appear in NEWS, put an asterisk in column zero of the
start of the ChangeLog entry, like so:

Sat Aug  3 01:27:14 1996  Gary Houston  <ghouston@actrix.gen.nz>

*	* fports.c (scm_open_file): don't return #f, throw error.

When you've written a NEWS entry and updated the documentation, go
ahead and remove the asterisk.  I will use the asterisks to find and
document changes that haven't been dealt with before a release.

- Include each log entry in both the ChangeLog and in the CVS logs.
If you're using Emacs, the pcl-cvs interface to CVS has features to
make this easier; it checks the ChangeLog, and generates good default
CVS log entries from that.

- There's no need to keep a change log for documentation files.  This
is because documentation is not susceptible to bugs that are hard to
fix.  Documentation does not consist of parts that must interact in a
precisely engineered fashion; to correct an error, you need not know
the history of the erroneous passage.  (This is copied from the GNU
coding standards.)

- If you add or remove files, don't forget to update the appropriate
part of the relevant Makefile.am files, and regenerate the
Makefile.in.  If you forget this, the snapshot and distribution
processes will not work.

- Make sure you have papers from people before integrating their
changes or contributions.  This is very frustrating, but very
important to do right.  From maintain.texi, "Information for
Maintainers of GNU Software":

    When incorporating changes from other people, make sure to follow the
    correct procedures.  Doing this ensures that the FSF has the legal
    right to distribute and defend GNU software.

    For the sake of registering the copyright on later versions ofthe
    software you need to keep track of each person who makes significant
    changes.  A change of ten lines or so, or a few such changes, in a
    large program is not significant.

    *Before* incorporating significant changes, make sure that the person
    has signed copyright papers, and that the Free Software Foundation has
    received them.

If you receive contributions you want to use from someone, let me know
and I'll take care of the administrivia.  Put the contributions aside
until we have the necessary papers.

- When you make substantial changes to a file, add the current year to
the list of years in the copyright notice at the top of the file.

- [From Mikael Djurfeldt] When working on the Guile internals, it is
quite often practical to implement a scheme-level procedure which
helps you examine the feature you're working on.

Examples of such procedures are: pt-size, debug-hand and
current-pstate.

I've now put #ifdef GUILE_DEBUG around all such procedures, so that
they are not compiled into the "normal" Guile library.  Please do the
same when you add new procedures/C functions for debugging purpose.

You can define the GUILE_DEBUG flag by passing --enable-guile-debug to
the configure script.


Jim Blandy