crosstool-ng/docs/7 - Contributing to crosstool-NG.txt

File.........: 7 - Contributing to crosstool-NG.txt
Copyrigth....: (C) 2010 Yann E. MORIN <yann.morin.1998@anciens.enib.fr>
License......: Creative Commons Attribution Share Alike (CC-by-sa), v2.5


Contributing to crosstool-NG  /
_____________________________/


Sending a bug report |
---------------------+

If you need to send a bug report, please send a mail with subject
prefixed with "[CT_NG]" with to following destinations:
    TO: yann.morin.1998 (at) anciens.enib.fr
    CC: crossgcc (at) sourceware.org


Sending patches |
----------------+

If you want to enhance crosstool-NG, there's a to-do list in the TODO file.

Patches should come with the appropriate SoB line. A SoB line is typically
something like:
   Signed-off-by: John DOE <john.doe@somewhere.net>

The SoB line is clearly described in Documentation/SubmittingPatches , section
12, of your favourite Linux kernel source tree.


How to Use Mercurial |
---------------------+

For larger or more frequent contributions, mercurial should be used.

PREREQUISITES:

Configuring Mercurial:
  You need mercurial with the following extensions:
   - mq        : http://mercurial.selenic.com/wiki/MqExtension
   - patchbomb : http://mercurial.selenic.com/wiki/PatchbombExtension
  Usually, these two extensions are already part of the installation package.
  The mq extension maintains a separate queue of your local changes
  that you can change at any later time.
  With the patchbomb extension you can email those patches directly
  from your local repo.

  Your configuration file for mercurial, e.g. ~/.hgrc should contain
  at least the following sections (but have a look at `man hgrc`):
  # ---
  [email]
  # configure sending patches directly via Mercurial
  from = "Your Name" <your@email.address>
  # How to send email:
  method = smtp

  [smtp]
  # SMTP configuration (only for method=smtp)
  host = localhost
  tls = true
  username =
  password =

  [extensions]
  # The following lines enable the two extensions:
  hgext.mq =
  hgext.patchbomb =
  # ----

Create your local repository as a clone:
  hg clone http://ymorin.is-a-geek.org/hg/crosstool-ng crosstool-ng

Setting up the mq extension in your local copy:
  cd crosstool-ng
  hg qinit


CREATING PATCHES:

Recording your changes in the patch queue maintained by mq:
  # First, create a new patch entry in the patch queue:
  hg qnew -D -U -e short_patch_name1
  <edit patch description as commit message (see below for an example)>

  <now edit the ct-ng sources and check them>

  # if you execute `hg status` here, your modifications of the working
  # copy should show up.

  # Now the following command takes your modifications from the working copy
  # into the patch entry
  hg qrefresh -D [-e]
  <reedit patch description [-e] if desired>

  # Now your changes are recorded, and `hg status` should show a clean
  # working copy

Repeat the above steps for all your modifications.
The command `hg qseries` informs you about the content of your patch queue.


CONTRIBUTING YOUR PATCHES:

Once you are satisfied with your patch series, you can (you should!)
contribute them back to upstream.
This is easily done using the `hg email` command.

`hg email` sends your new changesets to a specified list of recipients,
each patch in its own email, all ordered in the way you entered them (oldest
first). The command line flag --outgoing selects all changesets that are in
your local but not yet in the upstream repository. Here, these are exactly
the ones you entered into your local patch queue in the section above, so
--outgoing is what you want.

Each email gets the subject set to:  "[PATCH x of n] <series summary>"
where 'x' is the serial number in the email series, and 'n' is the total number
of patches in the series. The body of the email is the complete patch, plus
a handful of metadata, that helps properly apply the patch, keeping the log
message, attribution and date, tracking file changes (move, delete, modes...)

`hg email` also threads all outgoing patch emails below an introductory
message. You should use the introductory message (command line flag --intro)
to describe the scope and motivation for the whole patch series. The subject
for the introductory message gets set to:  "[PATCH 0 of n] <series summary>"
and you get the chance to set the <series summary>.

Here is a sample `hg email` complete command line:
Note: replace " (at) " with "@"

  hg email --outgoing --intro   \
           --to '"Yann E. MORIN" <yann.morin.1998 (at) anciens.enib.fr>'    \
           --cc 'crossgcc (at) sourceware.org'

  # It then opens an editor and lets you enter the subject
  # and the body for the introductory message.

Use `hg email` with the additional command line switch -n to
first have a look at the email(s) without actually sending them.


MAINTAINING YOUR PATCHES:

When the patches are refined by discussing them on the mailing list,
you may want to finalize and resend them.

The mq extension has the idiosyncrasy of imposing a stack onto the queue:
You can always reedit/refresh only the patch on top of stack.
The queue consists of applied and unapplied patches
(if you reached here via the above steps, all of your patches are applied),
where the 'stack' consists of the applied patches, and 'top of stack'
is the latest applied patch.

The following output of `hg qseries` is now used as an example:
  0 A short_patch_name1
  1 A short_patch_name2
  2 A short_patch_name3
  3 A short_patch_name4

You are now able to edit patch 'short_patch_name4' (which is top of stack):
  <Edit the sources>
  # and execute again
  hg qrefresh -D [-e]
  <and optionally [-e] reedit the commit message>

If you want to edit e.g. patch short_patch_name2, you have to modify
mq's stack so this patch gets top of stack.
For this purpose see `hg help qgoto`, `hg help qpop`, and `hg help qpush`.

  hg qgoto short_patch_name2
  # The patch queue should now look like
  hg qseries
    0 A short_patch_name1
    1 A short_patch_name2
    2 U short_patch_name3
    3 U short_patch_name4
  # so patch # 1 (short_patch_name2) is top of stack.
  <now reedit the sources for short_patch_name2>
  # and execute again
  hg qrefresh -D [-e]
  <and optionally [-e] reedit the commit message>
  # the following command reapplies the now unapplied two patches:
  hg qpush -a
  # you can also use `hg qgoto short_patch_name4` to get there again.


RESENDING YOUR REEDITED PATCHES:

By mailing list policy, please resend your complete patch series.
--> Go back to section "CONTRIBUTING YOUR PATCHES" and resubmit the full set.


SYNCING WITH UPSTREAM AGAIN:

You can sync your repo with upstream at any time by executing
  # first unapply all your patches:
  hg qpop -a
  # next fetch new changesets from upstream
  hg pull
  # then update your working copy
  hg up
  # optionally remove already upstream integrated patches (see below)
  hg qdelete <short_name_of_already_applied_patch>
  # and reapply your patches if any non upstream-integrated left (but see below)
  hg qpush -a

Eventually, your patches get included into the upstream repository
which you initially cloned.
In this case, before executing the hg qpush -a from above
you should manually "hg qdelete" the patches that are already integrated upstream.


HOW TO FORMAT COMMIT MESSAGES (aka patch desciptions):

Commit messages should look like (without leading pipes):
 |component: short, one-line description
 |
 |optional longer description
 |on multiple lines if needed

Here is an example commit message (see revision a53a5e1d61db):
 |comp-libs/cloog: fix building
 |
 |For CLooG/PPL 0.15.3, the directory name was simply cloog-ppl.
 |For any later versions, the directory name does have the version, such as
 |cloog-ppl-0.15.4.