xref: /openbmc/u-boot/tools/patman/README (revision 643ad899)
1# Copyright (c) 2011 The Chromium OS Authors.
2#
3# SPDX-License-Identifier:	GPL-2.0+
4#
5
6What is this?
7=============
8
9This tool is a Python script which:
10- Creates patch directly from your branch
11- Cleans them up by removing unwanted tags
12- Inserts a cover letter with change lists
13- Runs the patches through checkpatch.pl and its own checks
14- Optionally emails them out to selected people
15
16It is intended to automate patch creation and make it a less
17error-prone process. It is useful for U-Boot and Linux work so far,
18since it uses the checkpatch.pl script.
19
20It is configured almost entirely by tags it finds in your commits.
21This means that you can work on a number of different branches at
22once, and keep the settings with each branch rather than having to
23git format-patch, git send-email, etc. with the correct parameters
24each time. So for example if you put:
25
26Series-to: fred.blogs@napier.co.nz
27
28in one of your commits, the series will be sent there.
29
30In Linux and U-Boot this will also call get_maintainer.pl on each of your
31patches automatically (unless you use -m to disable this).
32
33
34How to use this tool
35====================
36
37This tool requires a certain way of working:
38
39- Maintain a number of branches, one for each patch series you are
40working on
41- Add tags into the commits within each branch to indicate where the
42series should be sent, cover letter, version, etc. Most of these are
43normally in the top commit so it is easy to change them with 'git
44commit --amend'
45- Each branch tracks the upstream branch, so that this script can
46automatically determine the number of commits in it (optional)
47- Check out a branch, and run this script to create and send out your
48patches. Weeks later, change the patches and repeat, knowing that you
49will get a consistent result each time.
50
51
52How to configure it
53===================
54
55For most cases of using patman for U-Boot development, patman will
56locate and use the file 'doc/git-mailrc' in your U-Boot directory.
57This contains most of the aliases you will need.
58
59For Linux the 'scripts/get_maintainer.pl' handles figuring out where
60to send patches pretty well.
61
62During the first run patman creates a config file for you by taking the default
63user name and email address from the global .gitconfig file.
64
65To add your own, create a file ~/.patman like this:
66
67>>>>
68# patman alias file
69
70[alias]
71me: Simon Glass <sjg@chromium.org>
72
73u-boot: U-Boot Mailing List <u-boot@lists.denx.de>
74wolfgang: Wolfgang Denk <wd@denx.de>
75others: Mike Frysinger <vapier@gentoo.org>, Fred Bloggs <f.bloggs@napier.net>
76
77<<<<
78
79Aliases are recursive.
80
81The checkpatch.pl in the U-Boot tools/ subdirectory will be located and
82used. Failing that you can put it into your path or ~/bin/checkpatch.pl
83
84
85If you want to change the defaults for patman's command-line arguments,
86you can add a [settings] section to your .patman file.  This can be used
87for any command line option by referring to the "dest" for the option in
88patman.py.  For reference, the useful ones (at the moment) shown below
89(all with the non-default setting):
90
91>>>
92
93[settings]
94ignore_errors: True
95process_tags: False
96verbose: True
97
98<<<
99
100
101If you want to adjust settings (or aliases) that affect just a single
102project you can add a section that looks like [project_settings] or
103[project_alias].  If you want to use tags for your linux work, you could
104do:
105
106>>>
107
108[linux_settings]
109process_tags: True
110
111<<<
112
113
114How to run it
115=============
116
117First do a dry run:
118
119$ ./tools/patman/patman -n
120
121If it can't detect the upstream branch, try telling it how many patches
122there are in your series:
123
124$ ./tools/patman/patman -n -c5
125
126This will create patch files in your current directory and tell you who
127it is thinking of sending them to. Take a look at the patch files.
128
129$ ./tools/patman/patman -n -c5 -s1
130
131Similar to the above, but skip the first commit and take the next 5. This
132is useful if your top commit is for setting up testing.
133
134
135How to add tags
136===============
137
138To make this script useful you must add tags like the following into any
139commit. Most can only appear once in the whole series.
140
141Series-to: email / alias
142	Email address / alias to send patch series to (you can add this
143	multiple times)
144
145Series-cc: email / alias, ...
146	Email address / alias to Cc patch series to (you can add this
147	multiple times)
148
149Series-version: n
150	Sets the version number of this patch series
151
152Series-prefix: prefix
153	Sets the subject prefix. Normally empty but it can be RFC for
154	RFC patches, or RESEND if you are being ignored.
155
156Series-name: name
157	Sets the name of the series. You don't need to have a name, and
158	patman does not yet use it, but it is convenient to put the branch
159	name here to help you keep track of multiple upstreaming efforts.
160
161Cover-letter:
162This is the patch set title
163blah blah
164more blah blah
165END
166	Sets the cover letter contents for the series. The first line
167	will become the subject of the cover letter
168
169Cover-letter-cc: email / alias
170	Additional email addresses / aliases to send cover letter to (you
171	can add this multiple times)
172
173Series-notes:
174blah blah
175blah blah
176more blah blah
177END
178	Sets some notes for the patch series, which you don't want in
179	the commit messages, but do want to send, The notes are joined
180	together and put after the cover letter. Can appear multiple
181	times.
182
183Commit-notes:
184blah blah
185blah blah
186more blah blah
187END
188	Similar, but for a single commit (patch). These notes will appear
189	immediately below the --- cut in the patch file.
190
191 Signed-off-by: Their Name <email>
192	A sign-off is added automatically to your patches (this is
193	probably a bug). If you put this tag in your patches, it will
194	override the default signoff that patman automatically adds.
195	Multiple duplicate signoffs will be removed.
196
197 Tested-by: Their Name <email>
198 Reviewed-by: Their Name <email>
199 Acked-by: Their Name <email>
200	These indicate that someone has tested/reviewed/acked your patch.
201	When you get this reply on the mailing list, you can add this
202	tag to the relevant commit and the script will include it when
203	you send out the next version. If 'Tested-by:' is set to
204	yourself, it will be removed. No one will believe you.
205
206Series-changes: n
207- Guinea pig moved into its cage
208- Other changes ending with a blank line
209<blank line>
210	This can appear in any commit. It lists the changes for a
211	particular version n of that commit. The change list is
212	created based on this information. Each commit gets its own
213	change list and also the whole thing is repeated in the cover
214	letter (where duplicate change lines are merged).
215
216	By adding your change lists into your commits it is easier to
217	keep track of what happened. When you amend a commit, remember
218	to update the log there and then, knowing that the script will
219	do the rest.
220
221Patch-cc: Their Name <email>
222	This copies a single patch to another email address. Note that the
223	Cc: used by git send-email is ignored by patman, but will be
224	interpreted by git send-email if you use it.
225
226Series-process-log: sort, uniq
227	This tells patman to sort and/or uniq the change logs. It is
228	assumed that each change log entry is only a single line long.
229	Use 'sort' to sort the entries, and 'uniq' to include only
230	unique entries. If omitted, no change log processing is done.
231	Separate each tag with a comma.
232
233Various other tags are silently removed, like these Chrome OS and
234Gerrit tags:
235
236BUG=...
237TEST=...
238Change-Id:
239Review URL:
240Reviewed-on:
241Commit-xxxx: (except Commit-notes)
242
243Exercise for the reader: Try adding some tags to one of your current
244patch series and see how the patches turn out.
245
246
247Where Patches Are Sent
248======================
249
250Once the patches are created, patman sends them using git send-email. The
251whole series is sent to the recipients in Series-to: and Series-cc.
252You can Cc individual patches to other people with the Patch-cc: tag. Tags
253in the subject are also picked up to Cc patches. For example, a commit like
254this:
255
256>>>>
257commit 10212537b85ff9b6e09c82045127522c0f0db981
258Author: Mike Frysinger <vapier@gentoo.org>
259Date:	Mon Nov 7 23:18:44 2011 -0500
260
261    x86: arm: add a git mailrc file for maintainers
262
263    This should make sending out e-mails to the right people easier.
264
265    Patch-cc: sandbox, mikef, ag
266    Patch-cc: afleming
267<<<<
268
269will create a patch which is copied to x86, arm, sandbox, mikef, ag and
270afleming.
271
272If you have a cover letter it will get sent to the union of the Patch-cc
273lists of all of the other patches. If you want to sent it to additional
274people you can add a tag:
275
276Cover-letter-cc: <list of addresses>
277
278These people will get the cover letter even if they are not on the To/Cc
279list for any of the patches.
280
281
282Example Work Flow
283=================
284
285The basic workflow is to create your commits, add some tags to the top
286commit, and type 'patman' to check and send them.
287
288Here is an example workflow for a series of 4 patches. Let's say you have
289these rather contrived patches in the following order in branch us-cmd in
290your tree where 'us' means your upstreaming activity (newest to oldest as
291output by git log --oneline):
292
293    7c7909c wip
294    89234f5 Don't include standard parser if hush is used
295    8d640a7 mmc: sparc: Stop using builtin_run_command()
296    0c859a9 Rename run_command2() to run_command()
297    a74443f sandbox: Rename run_command() to builtin_run_command()
298
299The first patch is some test things that enable your code to be compiled,
300but that you don't want to submit because there is an existing patch for it
301on the list. So you can tell patman to create and check some patches
302(skipping the first patch) with:
303
304    patman -s1 -n
305
306If you want to do all of them including the work-in-progress one, then
307(if you are tracking an upstream branch):
308
309    patman -n
310
311Let's say that patman reports an error in the second patch. Then:
312
313    git rebase -i HEAD~6
314    <change 'pick' to 'edit' in 89234f5>
315    <use editor to make code changes>
316    git add -u
317    git rebase --continue
318
319Now you have an updated patch series. To check it:
320
321    patman -s1 -n
322
323Let's say it is now clean and you want to send it. Now you need to set up
324the destination. So amend the top commit with:
325
326    git commit --amend
327
328Use your editor to add some tags, so that the whole commit message is:
329
330    The current run_command() is really only one of the options, with
331    hush providing the other. It really shouldn't be called directly
332    in case the hush parser is bring used, so rename this function to
333    better explain its purpose.
334
335    Series-to: u-boot
336    Series-cc: bfin, marex
337    Series-prefix: RFC
338    Cover-letter:
339    Unified command execution in one place
340
341    At present two parsers have similar code to execute commands. Also
342    cmd_usage() is called all over the place. This series adds a single
343    function which processes commands called cmd_process().
344    END
345
346    Change-Id: Ica71a14c1f0ecb5650f771a32fecb8d2eb9d8a17
347
348
349You want this to be an RFC and Cc the whole series to the bfin alias and
350to Marek. Two of the patches have tags (those are the bits at the front of
351the subject that say mmc: sparc: and sandbox:), so 8d640a7 will be Cc'd to
352mmc and sparc, and the last one to sandbox.
353
354Now to send the patches, take off the -n flag:
355
356   patman -s1
357
358The patches will be created, shown in your editor, and then sent along with
359the cover letter. Note that patman's tags are automatically removed so that
360people on the list don't see your secret info.
361
362Of course patches often attract comments and you need to make some updates.
363Let's say one person sent comments and you get an Acked-by: on one patch.
364Also, the patch on the list that you were waiting for has been merged,
365so you can drop your wip commit. So you resync with upstream:
366
367    git fetch origin		(or whatever upstream is called)
368    git rebase origin/master
369
370and use git rebase -i to edit the commits, dropping the wip one. You add
371the ack tag to one commit:
372
373    Acked-by: Heiko Schocher <hs@denx.de>
374
375update the Series-cc: in the top commit:
376
377    Series-cc: bfin, marex, Heiko Schocher <hs@denx.de>
378
379and remove the Series-prefix: tag since it it isn't an RFC any more. The
380series is now version two, so the series info in the top commit looks like
381this:
382
383    Series-to: u-boot
384    Series-cc: bfin, marex, Heiko Schocher <hs@denx.de>
385    Series-version: 2
386    Cover-letter:
387    ...
388
389Finally, you need to add a change log to the two commits you changed. You
390add change logs to each individual commit where the changes happened, like
391this:
392
393    Series-changes: 2
394    - Updated the command decoder to reduce code size
395    - Wound the torque propounder up a little more
396
397(note the blank line at the end of the list)
398
399When you run patman it will collect all the change logs from the different
400commits and combine them into the cover letter, if you have one. So finally
401you have a new series of commits:
402
403    faeb973 Don't include standard parser if hush is used
404    1b2f2fe mmc: sparc: Stop using builtin_run_command()
405    cfbe330 Rename run_command2() to run_command()
406    0682677 sandbox: Rename run_command() to builtin_run_command()
407
408so to send them:
409
410    patman
411
412and it will create and send the version 2 series.
413
414General points:
415
4161. When you change back to the us-cmd branch days or weeks later all your
417information is still there, safely stored in the commits. You don't need
418to remember what version you are up to, who you sent the last lot of patches
419to, or anything about the change logs.
420
4212. If you put tags in the subject, patman will Cc the maintainers
422automatically in many cases.
423
4243. If you want to keep the commits from each series you sent so that you can
425compare change and see what you did, you can either create a new branch for
426each version, or just tag the branch before you start changing it:
427
428    git tag sent/us-cmd-rfc
429    ...later...
430    git tag sent/us-cmd-v2
431
4324. If you want to modify the patches a little before sending, you can do
433this in your editor, but be careful!
434
4355. If you want to run git send-email yourself, use the -n flag which will
436print out the command line patman would have used.
437
4386. It is a good idea to add the change log info as you change the commit,
439not later when you can't remember which patch you changed. You can always
440go back and change or remove logs from commits.
441
442
443Other thoughts
444==============
445
446This script has been split into sensible files but still needs work.
447Most of these are indicated by a TODO in the code.
448
449It would be nice if this could handle the In-reply-to side of things.
450
451The tests are incomplete, as is customary. Use the --test flag to run them,
452and make sure you are in the tools/patman directory first:
453
454    $ cd /path/to/u-boot
455    $ cd tools/patman
456    $ ./patman --test
457
458Error handling doesn't always produce friendly error messages - e.g.
459putting an incorrect tag in a commit may provide a confusing message.
460
461There might be a few other features not mentioned in this README. They
462might be bugs. In particular, tags are case sensitive which is probably
463a bad thing.
464
465
466Simon Glass <sjg@chromium.org>
467v1, v2, 19-Oct-11
468revised v3 24-Nov-11
469