cvsimport

[fvwm.git] / docs / DEVELOPER-CVS

CVS INFORMATION
---------------

FVWM development uses a CVS server.

Note: the state of code in the CVS repository fluctuates wildly. It will
contain bugs, maybe ones that crash the program. It may not even compile for
you. Consider it alpha-quality code. You have been warned.

CONTENTS

Before You Begin Initial Setup Checking Out Source Code Building The Tree
Code Updates Starting a Project Hacking the Code Conflicts Getting Commit
Access Committing Changes Adding Directories and Files Deleting Directories
and Files Renaming/Moving Files Creating New Branches Creating New Source
Trees Working on the fvwm-web Source Tree Before You Begin [top]

To know what is going in with the source tree you should be reading mail on
the Fvwm Workers List. See the Mailing List Info page for more information.

To build FVWM from the CVS sources, you must have several GNU tools:

the CVS client version 1.9 or better, GCC, GNU make, autoconf, version 2.13
or better, and automake, version 1.4 or better.  Without these tools, you
won't be able to build out of the CVS source tree. But don't despair:
download one of the daily snapshots instead!

INITIAL SETUP
-------------

To make life easier on yourself, create the file `~/.cvsrc', and insert the
following lines. These set useful default options for the three most used
CVS commands. Do this now before going any further.

    diff -u 
    checkout -P 
    update -d -P 
    cvs -q 

The last line makes cvs operations quieter, but you still get full error
messages.

Also, if you are on a slow net link (like a dialup), you'll also want a line
containing `cvs -z3' in this file. This turns on a useful compression level
for all cvs commands. Setting it higher will only waste your CPU time.

Before you can download development source code for the first time, you must
login to the server:

    cvs -d :pserver:anonymous@cvs.fvwm.org:/home/cvs/fvwm login

The password is `guest'. The command outputs nothing if it works, and an
error message if it failed. You only need to log in once; all subsequent CVS
commands read the password stored in the file `~/.cvspass'.

CHECKING OUT SOURCE CODE
------------------------

Next, you checkout the source code. First you must decide what version
you're interested in. The structure of the CVS tree is as follows:

The latest code is always available at the tip of the main branch.  All
branches are labeled as branch-ver. So, for example, as development of the
2.3.x (latest) code continues on the main branch, a branch branch-2_2 has
been created for changes that would go into a 2.2.1 or future release.  At
various points we decide to checkpoint the code with a version number
change; there is always a label associated with every version number as
well. The label will have the format version-ver; for example,
version-2_1_13 or version-2_2_1.  Given these rules, you should be able to
translate the version of you want to retrieve to a label for use with the
checkout command below (or other CVS commands which might need them).

You use the CVS checkout (or co) command to retrieve an initial copy of the
code. The simplest form of this command, for retrieving the latest code,
doesn't require any label:

    cvs -d :pserver:anonymous@cvs.fvwm.org:/home/cvs/fvwm checkout fvwm

This will create a new directory fvwm in your current directory, containing
the latest, up-to-the-minute code.

If you want to work on the latest code in the 2.2.x branch of the code, you
can use the branch label on the checkout command line:

    cvs -d :pserver:anonymous@cvs.fvwm.org:/home/cvs/fvwm co -r branch-2_2 fvwm

This will put a copy of the very latest code on the 2.2.x branch into a
subdirectory fvwm. If you're going to be working on multiple branches at the
same time, or just feel like it, you can tell CVS to use a different name
for the directory with the checkout -d option:

    cvs -d :pserver:anonymous@cvs.fvwm.org:/home/cvs/fvwm co -r branch-2_2 \
        -d fvwm-2.2.x fvwm

Now the code will be checked out into a directory fvwm-2.2.x rather than
fvwm. In this way you can keep multiple copies of the source around and
"active" simultaneously. (It is also permissible to just checkout into fvwm
and rename the directory yourself.)

Finally, if you want to see a particular version of the sources you can use
a version label instead of a branch label on the checkout command:

    cvs -d :pserver:anonymous@cvs.fvwm.org:/home/cvs/fvwm co -r \
        version-2_1_10 -d fvwm-2.1.10 fvwm

Please note that if you check out a specific version, the update command
will be useless in that copy: after all, the code for that version hasn't
changed so there's nothing to update...

The version and branch labels "stick" to your copy of the tree, so that if
you check out a branch, all update commands will be handled with respect to
that branch. These are called "sticky tags"; please see the CVS
documentation for more details on these and how they work, or how to
"un-stick" a checked out version if you need to.

Note that when you are inside the working directory, you no longer need the
"-d :pserver:..." argument when issuing CVS commands.

CVS commands work from anywhere inside the source tree, and recurse
downwards. So if you happen to issue an update from inside the `docs'
subdirectory it will work fine, but only update the docs. In all of the
following command examples, we assume that you have cd'd to the top of the
source tree.

BUILDING THE TREE
-----------------

So, you now have a copy of the code. Get in there and get to work!

The first thing you need to do is create a configure script. The configure
script will also need the Makefile.in files in order to generate the
Makefiles. The autoconf and automake tools do this for you (you did remember
to install autoconf and automake, right?)

So, when you have a newly checked-out source tree the first thing to do is:

    utils/configure_dev.sh

in the cvs tree, it may be run with usual ./configure arguments instead of
all auto commands above.

Once that's done, you can proceed to build the code as discussed in the
INSTALL.fvwm and INSTALL files:

    ./configure && make && make install

with appropriate options and arguments, as you like.

CODE UPDATES
------------ 

From time to time, the dedicated FVWM Workers will make changes to the CVS
repository. Announcements of this are automatically sent to the fvwm-workers
list. You will want to be subscribed to this list!

You can update your copy of the sources to match the master repository with
the update command. Note it's not necessary to check out a new copy! Using
update is significantly faster and simpler, as it will download only patches
instead of entire files, only update files that have changed since your last
update, and it will automatically merge any changes in the CVS repository
with any local changes you may have made.

    cvs update

If you didn't use a tag when you checked out, this will update your sources
to the latest version on the main branch. If you used a branch tag, it will
update to the latest version on that branch. If you used a version tag, it
won't do anything (see above).

After updating the local source directory, it is usually enough to issue
make to rebuild everything. It is safe to manually run aclocal, automake and
autoconf if you think something should be rebuilt, but this sould be run
automatically on make.

STARTING A PROJECT
------------------

Discuss your ideas on the workers list before you start. Someone may be
working on the same thing you have in mind. Or they may have good ideas
about how to go about it.

If you just have a small patch you want to make, you may just commit it to
the main branch. If the change is large, and lots of other work is going on,
you may want to do your changes on a "side branch" which will get merged
into the main branch later on. Before creating a branch, you discuss the
matter with the other workers. If you are new to CVS, you should read the
CVS documentation several times, and ask for help. The documentation is
sufficiently large and confusing that it is rather difficult to get right
the first few times.

HACKING THE CODE 
----------------

So you've found a bug you want to fix?  Got a new feature to implement?
Hacking the code couldn't be easier. Just edit your copy of the sources.
No need to copy files to `.orig' or anything; CVS has copies of the originals.

When you have the code in a working state, generate a patch against the
current sources in the CVS repository.

    cvs update 
    cvs diff -u > patchfile

Mail the patch to the fvwm-workers list with a description of what you did.
But read the FAQ file about ChangeLog entries before doing so.

CONFLICTS
--------- 

If someone else has been working on the same files as you have, you may find
that you have made conflicting modifications. You'll discover this when you
try to update your sources.

    $ cvs update
    RCS file: /home/cvs/fvwm/fvwm/fvwm/icons.c,v
    retrieving revision 1.5
    retrieving revision 1.6
    Merging differences between 1.5 and 1.6 into icons.c
    rcsmerge: warning: conflicts during merge
    cvs server: conflicts found in fvwm/icons.c
    C fvwm/icons.c

Don't Panic! Your working file, as it existed before the update, is saved
under the filename `.#icons.c.1.5'; hence you can always recover it, should
things go horribly wrong. The file named `icons.c' now contains both the old
(i.e. your) version and new version of lines that conflicted. You simply
edit the file and resolve each conflict by deleting the unwanted version of
the lines involved.

    <<<<<<< icons.c
    XpmImage    my_image = {0};  /* testing */
    =======
    >>>>>>> 1.6

Don't forget to delete the lines with all the "<", "=", and ">" symbols.

GETTING COMMIT ACCESS 
---------------------

Using the procedures described above, and being on the workers list are a
prerequisite to gaining update access. We expect to have heard from you more
than once on the fvwm-workers list so that we have some idea who you are.

Doing some testing, submitting some patches, and getting involved in the
discussions will help us know about you.

After you have been involved for a while, if we don't suggest it, then ask.
The FVWM development team is not a closed environment, we welcome new
members. There are no required duties, all work is strictly voluntary.

If there is agreement on the list that you should be given update access,
you will need to choose a CVS user ID and provide an encrypted password. The
latter can be obtained with the following Perl snippet:

    perl -e 'print crypt("yourpass", join("", \
        ((a..z, A..Z, 0..9)[rand(62), rand(62)]))), "\n"'

Change yourpass to whatever you want your password to be. Send the encrypted
password to Jason Tibbitts, (tibbs@math.uh.edu). Jason is the list
maintainer, and provides our CVS repository.

Once you have update access, re-do the login command above using your CVS
user ID in place of anonymous and your password in place of guest, and you
are on your way.

COMMITTING CHANGES
------------------

Now that you have write permissions and have logged in with your CVS
username, you can commit changes. This is done (surprise!) with the CVS
commit command.

Note it's usually a good idea to run a cvs update just before you commit, to
make sure you've got the latest code. If you try to commit changes to a file
that someone else has changed since you last updated, CVS will complain and
not allow the commit. But, changes to other files could indirectly affect
your new code, as well. In general if you're doing development it really
pays to follow the old(?) adage, "Update early and often".

To commit all the modified files in your workspace, use:

    cvs commit

CVS will pop up your favorite editor to allow you to enter comments about
what changes you've made. These comments will appear in the email sent to
fvwm-workers, so please write something useful.

Also, you will see a complete list of files that CVS thinks you have
changed. Please sanity-check this list! Make sure there's nothing you don't
expect there, and everything you do expect.

If you don't like the all-or-nothing approach, you can specify only certain
files to be committed:

    cvs commit fvwm/fvwm.1 modules/FvwmAuto/FvwmAuto.1

Again, please sanity-check the list to be sure you have everything.

Adding Directories and Files [top]

First create the new directories and files locally. Then, assuming the new
directory is named `newdir' and the new file is `newmod.c':

    cvs add -m "New directory for ..." newdir
    cd newdir
    cvs add -m "File newmod.c is a module that ..." newmod.c
  
When adding new directories and files, please be sure to take a look at the
relevant Makefile.am files and modify them as appropriate! See the
DEVELOPERS file for more details on this.

DELETING DIRECTORIES AND FILES
------------------------------

You don't directly delete directories, you delete all the files in a
directory and the directory goes away during an `update -dP'. To delete one
or more files:

    cvs remove filename...  
    cvs commit -m 'deleted files because' filename...

Again, when removing directories or files please be sure to update the
appropriate Makefile.am files. See DEVELOPERS.

RENAMING/MOVING FILES 
---------------------

There is no perfect way to rename or move files in CVS. There are a few
different methods, each with good and bad points. For FVWM, we've chosen the
most straightforward method: remove the old file and add a new file. In
order to preserve some kind of link, please include a pointer to the old
file in the comments of the new file (and vice versa).

Again, when renaming or moving files please be sure to update the
appropriate Makefile.am files. See DEVELOPERS.

CREATING NEW BRANCHES
---------------------

Please contact the fvwm-workers list and discuss any new branch you'd like
to create, just so we have an idea about what and why.

When creating a branch it's best to base it off of a previously-existing,
labeled checkpoint. Here we'll use the example of creating a new branch for
2.2.x development after the 2.2 release was made. Because of our rules, we
know that the new branch name should be branch-2_2, but if you're creating a
branch for a new feature you can use any valid label.

Once you know where you want to branch from and what you want to call the
new branch, use the cvs rtag command to create the branch (be sure you're in
the root of your checkout):

    cvs rtag -b -r version-2_2_0 branch-2_2 .

The first thing you'll probably want to do on the new branch is edit the
configure.in file to change the version number, so people know it's
different. See the DEVELOPERS file for information on this.

CREATING NEW SOURCE TREES 
-------------------------

Please contact the fvwm-workers list and discuss any new source trees you'd
like to create, just so we have an idea about what and why.

The source code for Fvwm is in the "fvwm" source tree. At the time this
sentence was written, (September, 1999), there were 1 more source tree,
"fvwm-web".

If you have update access to "fvwm", you can also update the other source
trees and create new source trees.

WORKING ON THE FVWM-WEB SOURCE TREE
-----------------------------------

It's important to remember anything checked into the fvwm-web branch will
automatically appear on the fvwm web pages. Be careful to check your work
before you commit a change.

You can check to see what your changes will look like before a commit, by
using a "file:" URL to look at your changes with your browser. If you have
the fvwm-web source in /home/my/fvwm-web, your browser should be able to
view the source with the URL file:/home/my/fvwm-web. (This is one of the
reasons you want to use relative URLs to link one page to another.)

Some of the sub-directories in the fvwm-web branch can take a long time to
checkout or commit due to their large size. This is especially true over
dial-up connections. All of the CVS commands can be convinced to only work
on one directory or sub-directory by using the -l argument.

Some parts of the fvwm-web tree are generated from fvwm tree source files.
The generated files are in the directories:

    fvwm-web/authors/ 
    fvwm-web/news/ 
    fvwm-web/documentation/faq/
    fvwm-web/documentation/manpages/ 
    fvwm-web/documentation/perllib/ 

Each directory has a script generating one or more php files. You would normally
run these scripts (at least in the first 3 directories) whenever you made a
change to fvwm/NEWS, fvwm/docs/FAQ or fvwm/AUTHORS that you want to appear
on the fvwm web site. Instructions are in the scripts.