3 This directory contains tools intended to help committers use git when
4 interacting with standard FreeBSD project resources like Differential.
8 arcgit is a wrapper script around the arc command line tool that simplifies the
9 automatic creation of a series of Differential reviews from a series of git
10 commits. The intended workflow is:
12 1. Create a series of commits in git. Each commit will be a separate review, so
13 try to make each commit as self-contained as possible. The series of commits
14 should demonstrate a logical progression towards your end goal. For example,
15 one commit might refactor existing code to expose a new API without changing
16 any current functionality. A subsequent commit could then introduce your new
17 code that uses the new API.
19 It usually will not be helpful to present your code in the order in which it
20 was actually written and can actually be harmful. For example, if you
21 introduced a bug early in your development process that you fixed in a
22 subsequent commit, it is a waste of your reviewer's time to have them review
23 old code with known bugs. Instead, it would probably be best to squash the
24 bug fix into the commit that introduced it, so that the bug is never
25 presented to your reviewers in any review.
27 The commit headline and commit message will be imported verbatim into
28 Differential, so try to give each commit a meaningful commit message that
29 gives your reviewers the necessary context to understand your change.
31 2. Create your reviews by running this command in your git repo:
32 $ arcgit -r C1~..C2 -R reviewer -T testplan
34 C1 should be the first commit that you want reviewed, and C2 should be the
35 last commit that you want reviewed. You may add multiple reviewers by
36 specifying the -R option multiple times. You can CC (AKA subscribe) people
37 to a review with the -C option. Note that if you subscribe a mailing list
38 to a review, the mailing list will be emailed for every comment or change
39 made to each review. Please be judicious when subscribing mailing lists to
40 reviews. It may be better to instead send a single email to the appropriate
41 list announcing all of the reviews and giving a short summary of the change
42 as a whole, along with a link to the individual reviews.
44 3. When you need to make a change and upload it to a review, use the following
45 process. First, check out the branch corresponding to the review (arcgit
46 automatically creates this branch for every review that it creates):
48 $ git checkout review_D1234
50 Next, make your change and perform whatever testing is necessary. Commit it
51 to your repository with this command:
53 $ git commit --fixup HEAD
55 You can upload the change to the code review by running this command in your
56 repository while (ensure that you are still on the review_D1234 branch):
58 $ arc diff --update D1234 review_D1234_base
60 When you run arc, it will pull up your editor and give you a chance to
61 change the message that will be shown in Differential for this upload. It's
62 recommended that you change it from the default "fixup! ...." as that does
63 not give your reviewers an indication of what changes were made. It's not
64 recommended that you give the code review fixes meaningful commit messages
65 directly because we will be using git's autosquash feature in the next step,
66 which depends on the fixup! tag being present.
68 Do not merge in other branches, or rebase your review branches at this point.
69 Any changes that are made will show up in your reviews, and that will create
70 extra noise that your reviewers will have to ignore. If a reviewer requests
71 a change that requires your commit to be based off of a later version of
72 head, I would suggest deferring the change from the review and creating a
73 new review with the change once you hit step 5.
75 4. Once the reviews have been approved, you need to prepare your patch series
76 to be committed. This involves squashing the fixes made in code review
77 back into the original commit that they applied to. This gives you a clean
78 series of commits that are ready to be pushed to git.
80 First, merge each of your review branches back into your main development
83 $ git checkout myfeature_dev
84 $ for branch in review_D1234 review_D1235 review_D1236; do \
85 git merge $branch || git mergetool -y || break; done
87 Next, do an interactive rebase to squash your code review fixes back into the
90 $ git rebase -i -k review_D1234_base
92 review_D1234 should be the name of the *first* review that was created for
93 you in step 2. For every commit, your editor will be pulled up and you will
94 be given one last chance to edit your commit message. Make sure that you fill
95 in the "Reviewed by:" tag indicating who accepted the review. This would
96 be a good point to add other tags like MFC after:, Sponsored by:, etc.
98 The rebase will not introduce any actual changes to your code if done
99 properly. You can use this command to double-check that no changes were
100 inadvertently made here:
102 $ git diff myfeature_dev@{1}
104 5. Finally, you should get up to date with the latest changes from head:
106 $ git pull --rebase origin master
108 It is not recommended that you combine this step with the rebase done in the
109 previous step. The reason for this is that if you perform an interactive
110 rebase that changes the commit that you branch from, it becomes much more
111 difficult to use the reflog to confirm that the interactive rebase did not
112 introduce unwanted changes.
114 At this point, you are ready to commit your changes to head. The importgit
115 script can be used to import your commits directly into git.