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1 =========================================
2 TopGit -- A different patch queue manager
3 =========================================
6 DESCRIPTION
7 -----------
9 TopGit aims to make handling of large amounts of interdependent topic
10 branches easier. In fact, it is designed especially for the case where
11 you maintain a queue of third-party patches on top of another (perhaps
12 Git-controlled) project and want to easily organize, maintain and submit
13 them -- TopGit achieves that by keeping a separate topic branch for each
14 patch and providing some tools to maintain the branches.
16 See also:
18 :REQUIREMENTS_: Installation requirements
19 :SYNOPSIS_: Command line example session
20 :USAGE_: Command line details
21 :`NO UNDO`_: Where's the undo!!!
22 :CONVENTIONS_: Suggestions for organizing your TopGit branches
23 :`EXTRA SETTINGS`_: Various possible "topgit.*" config settings
24 :ALIASES_: Git-like TopGit command aliases
25 :NAVIGATION_: Getting around with "next" and "prev"
26 :GLOSSARY_: All the TopGit vocabulary in one place
27 :TECHNICAL_: How it works behind the scenes
28 :`TESTING TOPGIT`_: How to run the TopGit test suite
31 REQUIREMENTS
32 ------------
34 TopGit is a collection of POSIX shell scripts so a POSIX-compliant shell is
35 required along with some standard POSIX-compliant utilities (e.g. sed, awk,
36 cat, etc.). Git version 1.8.5 or later is also required.
38 To use TopGit with linked working trees (the ``git worktree add`` command),
39 at least Git version 2.5.0 (obviously, since that's when the ``git worktree``
40 command first appeared) is needed in which case linked working trees are then
41 fully supported for use with TopGit.
43 The scripts need to be preprocessed and installed. The Makefile that does
44 this only requires a POSIX make utility (using "``make``" and "``make install``").
45 Running the tests (see `TESTING TOPGIT`_) also requires only a POSIX make
46 utility ("``make test``") but does require a ``perl`` binary to be available.
48 It is possible to use the DESTDIR functionality to install TopGit to a
49 staging area on one machine, archive that and then unarchive it on another
50 machine to perform an install (provided the build prefix and other options are
51 compatible with the final installed location).
54 INSTALLATION
55 ------------
57 See the file ``INSTALL``.
60 GIT REPOSITORY
61 --------------
63 The TopGit git repository can be found at <http://repo.or.cz/topgit/pro>.
66 RATIONALE
67 ---------
69 Why not use something like StGIT or Guilt or ``rebase -i`` for maintaining
70 your patch queue? The advantage of these tools is their simplicity;
71 they work with patch *series* and defer to the reflog facility for
72 version control of patches (reordering of patches is not
73 version-controlled at all). But there are several disadvantages -- for
74 one, these tools (especially StGIT) do not actually fit well with plain
75 Git at all: it is basically impossible to take advantage of the index
76 effectively when using StGIT. But more importantly, these tools
77 horribly fail in the face of a distributed environment.
79 TopGit has been designed around three main tenets:
81 (i) TopGit is as thin a layer on top of Git as possible. You
82 still maintain your index and commit using Git; TopGit will only
83 automate a few indispensable tasks.
85 (ii) TopGit is anxious about *keeping* your history. It will
86 never rewrite your history, and all metadata is also tracked
87 by Git, smoothly and non-obnoxiously. It is good to have a
88 *single* point when the history is cleaned up, and that is at
89 the point of inclusion in the upstream project; locally, you
90 can see how your patch has evolved and easily return to older
91 versions.
93 (iii) TopGit is specifically designed to work in a
94 distributed environment. You can have several instances of
95 TopGit-aware repositories and smoothly keep them all
96 up-to-date and transfer your changes between them.
98 As mentioned above, the main intended use-case for TopGit is tracking
99 third-party patches, where each patch is effectively a single topic
100 branch. In order to flexibly accommodate even complex scenarios when
101 you track many patches where many are independent but some depend on
102 others, TopGit ignores the ancient Quilt heritage of patch series and
103 instead allows the patches to freely form graphs (DAGs just like Git
104 history itself, only "one level higher"). For now, you have to manually
105 specify which patches the current one depends on, but TopGit might help
106 you with that in the future in a darcs-like fashion.
108 A glossary_ plug: The union (i.e. merge) of patch dependencies is called
109 a *base* of the patch (topic branch).
111 Of course, TopGit is perhaps not the right tool for you:
113 (i) TopGit is not complicated, but StGIT et al. are somewhat
114 simpler, conceptually. If you just want to make a linear
115 purely-local patch queue, deferring to StGIT instead might
116 make more sense.
118 (ii) When using TopGit, your history can get a little hairy
119 over time, especially with all the merges rippling through.
120 ;-)
123 SYNOPSIS
124 --------
126 ::
128 ## Create and evolve a topic branch
129 $ tg create t/gitweb/pathinfo-action
130 tg: Automatically marking dependency on master
131 tg: Creating t/gitweb/pathinfo-action base from master...
132 $ ..hack..
133 $ git commit
134 $ ..fix a mistake..
135 $ git commit
137 ## Create another topic branch on top of the former one
138 $ tg create t/gitweb/nifty-links
139 tg: Automatically marking dependency on t/gitweb/pathinfo-action
140 tg: Creating t/gitweb/nifty-links base from t/gitweb/pathinfo-action...
141 $ ..hack..
142 $ git commit
144 ## Create another topic branch on top of master and submit
145 ## the resulting patch upstream
146 $ tg create t/revlist/author-fixed master
147 tg: Creating t/revlist/author-fixed base from master...
148 $ ..hack..
149 $ git commit
150 $ tg patch -m
151 tg: Sent t/revlist/author-fixed
152 From: pasky@suse.cz
153 To: git@vger.kernel.org
154 Cc: gitster@pobox.com
155 Subject: [PATCH] Fix broken revlist --author when --fixed-string
157 ## Create another topic branch depending on two others non-trivially
158 $ tg create t/whatever t/revlist/author-fixed t/gitweb/nifty-links
159 tg: Creating t/whatever base from t/revlist/author-fixed...
160 tg: Merging t/whatever base with t/gitweb/nifty-links...
161 Merge failed!
162 tg: Please commit merge resolution and call: tg update --continue
163 tg: It is also safe to abort this operation using `git reset --hard`
164 tg: but please remember you are on the base branch now;
165 tg: you will want to switch to a different branch.
166 $ ..resolve..
167 $ git commit
168 $ tg update --continue
169 $ ..hack..
170 $ git commit
172 ## Update a single topic branch and propagate the changes to
173 ## a different one
174 $ git checkout t/gitweb/nifty-links
175 $ ..hack..
176 $ git commit
177 $ git checkout t/whatever
178 $ tg info
179 Topic Branch: t/whatever (1 commit)
180 Subject: [PATCH] Whatever patch
181 Base: 3f47ebc1
182 Depends: t/revlist/author-fixed t/gitweb/nifty-links
183 Needs update from:
184 t/gitweb/nifty-links (1 commit)
185 $ tg update
186 tg: Updating base with t/gitweb/nifty-links changes...
187 Merge failed!
188 tg: Please commit merge resolution and call `tg update --continue`
189 tg: (use `tg status` to see more options)
190 $ ..resolve..
191 $ git commit
192 $ tg update --continue
193 tg: Updating t/whatever against new base...
194 Merge failed!
195 tg: Please commit merge resolution and call `tg update --continue`
196 tg: (use `tg status` to see more options)
197 $ ..resolve..
198 $ git commit
199 $ tg update --continue
201 ## Update a single topic branch and propagate the changes
202 ## further through the dependency chain
203 $ git checkout t/gitweb/pathinfo-action
204 $ ..hack..
205 $ git commit
206 $ git checkout t/whatever
207 $ tg info
208 Topic Branch: t/whatever (1/2 commits)
209 Subject: [PATCH] Whatever patch
210 Base: 0ab2c9b3
211 Depends: t/revlist/author-fixed t/gitweb/nifty-links
212 Needs update from:
213 t/gitweb/pathinfo-action (<= t/gitweb/nifty-links) (1 commit)
214 $ tg update
215 tg: Recursing to t/gitweb/nifty-links...
216 [t/gitweb/nifty-links] tg: Updating base with t/gitweb/pathinfo-action changes...
217 Merge failed!
218 [t/gitweb/nifty-links] tg: Please commit merge resolution and call `tg update --continue`
219 [t/gitweb/nifty-links] tg: (use `tg status` to see more options)
220 $ ..resolve..
221 $ git commit
222 $ tg update --continue
223 [t/gitweb/nifty-links] tg: Updating t/gitweb/nifty-links against new base...
224 Merge failed!
225 [t/gitweb/nifty-links] tg: Please commit merge resolution and call `tg update --continue`
226 [t/gitweb/nifty-links] tg: (use `tg status` to see more options)
227 $ ..resolve..
228 $ git commit
229 $ tg update --continue
230 tg: Updating base with t/gitweb/nifty-links changes...
231 tg: Updating t/whatever against new base...
233 ## Clone a TopGit-controlled repository
234 $ git clone URL repo
235 $ cd repo
236 $ tg remote --populate origin
237 ...
238 $ git fetch
239 $ tg update
241 ## Add a TopGit remote to a repository and push to it
242 $ git remote add foo URL
243 $ tg remote foo
244 $ tg push -r foo
246 ## Update from a non-default TopGit remote
247 $ git fetch foo
248 $ tg -r foo summary
249 $ tg -r foo update
252 CONVENTIONS
253 -----------
255 When using TopGit there are several common conventions used when working with
256 TopGit branches. None of them are enforced, they are only suggestions.
258 There are three typical uses for a TopGit branch:
260 1. [PATCH]
261 Normal TopGit branches that represent a single patch. These are known
262 as "patch" TopGit branches.
263 2. [BASE]
264 Empty TopGit branches with no dependencies (an empty ``.topdeps`` file)
265 that represent a base upon which other "normal" TopGit branches depend.
266 These are known as "base" TopGit branches (not to be confused with
267 the refs/top-bases/... refs).
268 3. [STAGE]
269 Empty TopGit branches that serve as a staging area to bring together
270 several other TopGit branches into one place so they can be used/tested
271 all together. These are known as "stage" TopGit branches.
273 An "empty" TopGit branch is one that does not have any changes of its own --
274 it may still have dependencies though ("stage" branches do, "base" branches do
275 not). The ``tg summary`` output shows empty branches with a ``0`` in the
276 listing. Normal "patch" branches that have not been annihilated, "base" and
277 "stage" branches fall into this category. (Annihilated branches are normally
278 omitted from the ``tg summary`` output but can be shown if given explicitly as
279 an argument to the ``tg summary`` command. However, the message line will be
280 incorrect since an annihilated branch has no ``.topmsg`` file of its own.)
282 A "patch" branch name typically starts with ``t/`` whereas "base" and "stage"
283 branch names often do not.
285 A "base" branch is created by using the ``--base`` option of ``tg create``
286 (aka ``--no-deps``) which will automatically suggest a "[BASE]" message prefix
287 rather than "[PATCH]". A "stage" branch is created like a normal patch branch
288 except that the only changes that will ever be made to it are typically to
289 add/remove dependencies. Its subject prefix must be manually changed to
290 "[STAGE]" to reflect its purpose.
292 Since both "base" and "stage" branches typically only have a use for the
293 "Subject:" line from their ``.topmsg`` file, they are quite easily created
294 using the ``--topmsg`` option of ``tg create``.
296 Use of "stage" and "base" branches is completely optional. However, without
297 use of a "stage" branch it will be difficult to test multiple independent
298 patches together all at once. A "base" branch is merely a convenience that
299 provides more explicit control over when a common base for a set of patches
300 gets updated as well as providing a branch that shows in ``tg summary`` output
301 and participates in ``tg remote --populate`` setup.
303 Occasionally the functionality of a "base" branch is needed but it may not
304 be possible to add any `.topdeps` or `.topmsg` files to the desired branch
305 (perhaps it's externally controlled). `BARE BRANCHES`_ can be used in this
306 case, but while TopGit allows them it deliberately does not provide assistance
307 in setting them up.
309 Another advantage to using a "stage" branch is that if a new "patch" branch
310 is created remotely and that new branch is added to a pre-existing "stage"
311 branch on the remote then when the local version of the "stage" branch is
312 updated (after fetching remote updates of course), that new dependency will
313 be merged into the local "stage" branch and the local version of the new remote
314 "patch" branch will be automatically set up at "tg update" time.
316 When using the ``tg tag`` command to create tags that record the current state
317 of one or more TopGit branches, the tags are often created with a name that
318 starts with ``t/``.
320 One last thing, you have enabled ``git rerere`` haven't you?
323 NO UNDO
324 -------
326 Beware, there is no "undo" after running a ``tg update``!
328 Well, that's not entirely correct. Since ``tg update`` never discards commits
329 an "undo" operation is technically feasible provided the old values of all the
330 refs that were affected by the ``tg update`` operation can be determined and
331 then they are simply changed back to their previous values.
333 In practice though, it can be extremely tedious and error prone looking through
334 log information to try and determine what the correct previous values were.
335 Although, since TopGit tries to make sure reflogs are enabled for top-bases
336 refs, using Git's ``@{date}`` notation on all the refs dumped out by a
337 ``tg tag --refs foo``, where "foo" is the branch that was updated whose update
338 needs to be undone, may work.
340 Alternatively, ``tg tag --stash`` can be used prior to the update and then
341 ``tg revert`` used after the update to restore the previous state. This
342 assumes, of course, that you remember to run ``tg tag --stash`` first.
344 The ``tg update`` command understands a ``--stash`` option that tells it to
345 automatically run ``tg tag --stash`` before it starts making changes (if
346 everything is up-to-date it won't run the stash command at all).
348 The ``--stash`` option is the default nowadays when running ``tg update``,
349 add the ``--no-stash`` option to turn it off.
351 There is a preference for this. Setting the config value ``topgit.autostash``
352 to ``false`` will implicitly add the ``--no-stash`` option to any ``tg update``
353 command unless an explicit ``--stash`` option is given.
355 If you are likely to ever want to undo a ``tg update``, setting
356 ``topgit.autostash`` to ``false`` is highly discouraged!
358 Note that the tags saved by ``tg tag --stash`` are stored in the
359 ``refs/tgstash`` ref and its reflog. Unfortunately, while Git is happy to
360 maintain the reflog (once it's been enabled which ``tg tag`` guarantees for
361 ``refs/tgstash``), Git is unable to view an annotated/signed tag's reflog!
362 Instead Git dereferences the tag and shows the wrong thing. Use the
363 ``tg tag -g`` command to view the ``refs/tgstash`` reflog instead.
366 EXTRA SETTINGS
367 --------------
369 TopGit supports various config settings:
371 :`tg create`_: ``format.signoff`` template Signed-off-by line
372 :ALIASES_: ``topgit.alias.*`` for Git-like command aliases
373 :`tg update`_: ``topgit.autostash`` automatic stash control
374 :`tg create`_: ``topgit.bcc`` default "Bcc:" value for create
375 :`tg create`_: ``topgit.cc`` default "Cc:" value for create
376 :`tg patch`_: ``topgit.from`` "From:" fixups by ``tg patch``
377 :`REMOTE HANDLING`_: ``topgit.remote`` TopGit's default remote
378 :SEQUESTRATION_: ``topgit.sequester`` for sequestration control
379 :`tg update`_: ``topgit.setAutoUpdate`` => ``rerere.autoUpdate``
380 :`tg create`_: ``topgit.subjectPrefix`` "[$prefix PATCH] foo"
381 :`tg create`_: ``topgit.to`` default "To:" value for create
382 :`tg migrate-bases`_: ``topgit.top-bases`` for refs bases location
385 ALIASES
386 -------
388 These work exactly like Git's aliases except they are stored under
389 ``topgit.alias.*`` instead. See the ``git help config`` output under
390 the ``alias.*`` section for details. Do note that while alias nesting is
391 explicitly permitted, a maximum nesting depth of 10 is enforced to help
392 detect accidental aliasing loops and keep them from wedging the machine.
394 For example, to create an ``lc`` alias for the ``tg log --compact`` command
395 this command may be used:
397 ::
399 git config --global topgit.alias.lc "log --compact"
401 To make it specific to a particular repository just omit the ``--global``
402 option from the command.
405 NAVIGATION
406 ----------
407 From Previous to Next
408 ~~~~~~~~~~~~~~~~~~~~~
410 For this section, consider the following patch series, to be applied
411 in numerical order as shown:
413 ::
415 0001-F_first-patch.diff
416 0002-G_second-builds-on-F.diff
417 0003-H_third-builds-on-G.diff
418 0004-I_fourth-builds-on-H.diff
419 0005-J_fifth-builds-on-I.diff
420 0006-K_sixth-builds-on-J.diff
421 0007-L_last-patch-needs-K.diff
423 If these were applied to some commit in a Git repository, say commit "A"
424 then a history that looks like this would be created:
426 ::
428 A---F---G---H---I---J---K---L
430 Where the parent of commit "F" is "A" and so on to where the parent of
431 commit "L" is commit "K".
433 If that commit history, from A through L, was then imported into TopGit, one
434 TopGit branch would be created corresponding to each of the commits F
435 through L. This way, for example, if the fourth patch in the series
436 (``0004-I_...diff``) needs work, the TopGit branch corresponding to its patch
437 can be checked out and changes made and then a new version of its patch
438 created (using ``tg patch``) without disturbing the other patches in the series
439 and when ``tg update`` is run, the patches that "follow" the fourth patch
440 (i.e. 5, 6 and 7) will have their corresponding TopGit branches automatically
441 updated to take into account the changes made to the fourth patch.
443 Okay, enough with the review of TopGit systemology
444 ``````````````````````````````````````````````````
446 Imagine then that you are working on the fourth patch (i.e. you have its
447 branch checked out into the working tree) and you want to move to the following
448 patch in the series because you have a nit to pick with it too.
450 If you can't remember the exact name you might have to fumble around or, you
451 can display the name of the following or "next" patch's branch with the, you
452 guessed it, ``tg next`` command. Think of "next" as the "next" logical patch
453 in the series or the next following patch. If the patches are numbered as in
454 the list above, "next" corresponds to the "+1" (plus one) patch.
456 You might have already guessed there's a corresponding ``tg prev`` command
457 which displays the "-1" (minus one) patch. If these commands (``tg next``
458 and ``tg prev``) are not given a branch name to start at they start at the
459 patch corresponding to the current ``HEAD``.
461 Displaying, however, is not so helpful as actually going there. That's where
462 the ``tg checkout`` command comes in. ``tg checkout next`` does a
463 ``git checkout`` of the ``tg next`` branch and, not surprisingly,
464 ``tg checkout prev`` does a ``git checkout`` of the ``tg prev`` branch. For
465 the lazy a single ``n`` or ``p`` can be used with ``tg checkout`` instead of
466 typing out the entire ``next`` or ``prev``. Or, for the anal, ``previous``
467 will also be accepted for ``prev``.
469 Referring to the A...L commit graph shown above, I is the parent of J and,
470 conversely, J is the child of I. (Git only explicitly records the child to
471 parent links, in other words a "child" points to zero or more "parents", but
472 parents are completely clueless about their own children.)
474 For historical reasons, the ``tg checkout`` command accepts ``child`` as a
475 synonym for ``next`` and ``parent`` as a synonym for ``prev``. However, this
476 terminology can be confusing since Git has "parent" links but ``tg checkout``
477 is referring to the TopGit DAG, not Git's. Best to just avoid using ``child``
478 or ``parent`` to talk about navigating the TopGit DAG and reserve them
479 strictly for discussing the Git DAG.
481 There may be more than one
482 ``````````````````````````
484 In a simple linear history as shown above there's always only one "next" or
485 "prev" patch. However, TopGit does not restrict one to only a linear
486 history (although that can make patch exports just a bushel of fun).
488 Suffice it to say that there is always a single linearized ordering for any
489 TopGit patch series since it's always a DAG (Directed Acyclic Graph), but it
490 may not be immediately obvious to the casual observer what that is.
492 The ``tg checkout`` command will display a list to choose from if ``next``
493 or ``prev`` would be ambiguous.
495 Use the ``tg info/checkout --series`` command
496 `````````````````````````````````````````````
498 To see the full, linearized, list of patches with their summary displayed in
499 order from first to last patch in the series, just run the ``tg info --series``
500 command. It takes the name of any patch in the series automatically using
501 ``HEAD`` if none is given. It even provides a nice "YOU ARE HERE" mark in
502 the output list helpful to those who have been absent for a time engaging in
503 otherwise distracting activities and need to be reminded where they are.
505 Using ``tg checkout --series`` can take you there (picking from a list) if
506 you've forgotten the way back to wherever you're supposed to be.
508 Don't get pushy, there's just one more thing
509 ````````````````````````````````````````````
511 For historical reasons, ``tg checkout`` with no arguments whatsoever behaves
512 like ``tg checkout next``. For the same historical reasons, ``tg checkout ..``
513 behaves like ``tg checkout prev`` (think of ``..`` as the "parent" directory
514 and since "parent" means "prev" in this context it will then make sense).
516 Now, for that one more thing. Consider that you have a pristine "upstream"
517 tarball, repository, source dump or otherwise obtained set of unmodified
518 source files that need to be patched. View them like so:
520 ::
522 +-------------------------------+
523 | Unmodified "upstream" source |
524 | files represented with "A" |
525 +-------------------------------+
527 Now, add the first patch, 0001, to them and view the result like so:
529 ::
531 +--------------------------+----+
532 | Patch 0001 represented by "F" |
533 +-------------------------------+
534 | Unmodified "upstream" source |
535 | files represented with "A" |
536 +-------------------------------+
538 Not stopping there, "push" patches 2, 3 and 4 onto the stack as well like so:
540 ::
542 +--------------------------+----+
543 | Patch 0004 represented by "I" |
544 +--------------------------+----+
545 | Patch 0003 represented by "H" |
546 +--------------------------+----+
547 | Patch 0002 represented by "G" |
548 +--------------------------+----+
549 | Patch 0001 represented by "F" |
550 +-------------------------------+
551 | Unmodified "upstream" source |
552 | files represented with "A" |
553 +-------------------------------+
555 In other words, to go to the "next" patch in the series it needs to be "push"ed
556 onto the stack. ``tg checkout`` accepts ``push`` as an alias for ``next``.
558 Similarly to go to the "previous" patch in the series the current one needs
559 to be "pop"ped off the stack. ``tg checkout`` accepts ``pop`` as an alias
560 for ``prev``.
562 Unfortunately for these aliases, in Git terminology a "push" has quite a
563 different meaning and the ``tg push`` command does something quite different
564 from ``tg checkout push``. Then there's the matter of using a single letter
565 abbreviation for the lazy -- ``p`` would mean what exactly?
567 ``tg checkout`` continues to accept the ``push`` and ``pop`` aliases for
568 ``next`` and ``prev`` respectively, but it's best to avoid them since
569 ``push`` has an alternate meaning everywhere else in TopGit and Git and that
570 leaves ``pop`` all alone in the dark.
573 SEQUESTRATION
574 -------------
576 No, this is not a section about budget nonsense. ;)
578 TopGit keeps its metadata in ``.topdeps`` and ``.topmsg`` files. In an effort
579 to facilitate cherry-picking and other Git activities on the patch changes
580 themselves while ignoring the TopGit metadata, TopGit attempts to keep all
581 changes to ``.topdeps`` and ``.topmsg`` files limited to commits that do NOT
582 contain changes to any other files.
584 This is a departure from previous TopGit versions that made no such effort.
586 Primarily this affects ``tg create`` and ``tg import`` (which makes use of
587 ``tg create``) as ``tg create`` will commit the initial versions of
588 ``.topdeps`` and ``.topmsg`` for a new TopGit-controlled branch in their own
589 commit instead of mixing them in with changes to other files.
591 The ``pre-commit`` hook will also attempt to separate out any ``.topdeps`` and
592 ``.topmsg`` changes from commits that include changes to other files.
594 It is possible to defeat these checks without much effort (``pre-commit`` hooks
595 can easily be bypassed, ``tg create`` has a ``--no-commit`` option, many Git
596 commands simply do not run the ``pre-commit`` hook, etc.).
598 If you really, really, really, really want to change the default back to the
599 old behavior of previous TopGit versions where no such sequestration took
600 place, then set the ``topgit.sequester`` config variable explicitly to the
601 value ``false``. But this is not recommended.
604 AMENDING AND REBASING AND UPDATE-REF'ING
605 ----------------------------------------
607 In a word, "don't".
609 It is okay to manually update a top-bases/... ref when a) it has no depedencies
610 (i.e. it was created with the ``tg create`` ``--base`` option) and b) the
611 old top-bases/... ref value can be fast-forwarded to the new top-bases/...
612 value OR the new value contains ALL of the changes in the old value through
613 some other mechanism (perhaps they were cherry-picked or otherwise applied to
614 the new top-bases/... ref). The same rules apply to non-TopGit-controlled
615 dependencies. Use the ``tg update --base <branch> <new-ref>`` command to
616 safely make such an update while making it easy to set the merge commit
617 message at the same time.
619 Ignoring this rule and proceeding anyway with a non-fast-forward update to a
620 top-bases/... ref will result in changes present in the new value being merged
621 into the branch (at ``tg update`` time) as expected (possibly with conflicts),
622 but any changes that were contained in the old version of the top-bases/... ref
623 which have been dropped (i.e. are NOT contained in the new version of the
624 top-bases/... ref) will continue to be present in the branch! To get rid of
625 the dropped commits, one or more "revert" commits will have to be manually
626 applied to the tip of the new top-bases/... value (which will then be merged
627 into the branch at next ``tg update`` time).
629 The only time it's safe to amend, rebase, filter or otherwise rewrite commits
630 contained in a TopGit controlled branch or non-TopGit branch is when those
631 commits are NOT reachable via any other ref!
633 Furthermore, while it is safe to rewrite merge commits (provided they meet the
634 same conditions) the merge commits themselves and the branches they are merging
635 in must be preserved during the rewrite and that can be rather tricky to get
636 right so it's not recommended.
638 For example, if, while working on a TopGit-controlled branch ``foo``, a bad
639 typo is noticed, it's okay to ammend/rebase to fix that provided neither
640 ``tg update`` nor ``tg create`` has already been used to cause some other ref
641 to be able to reach the commit with the typo.
643 If an amend or rerwite is done anyway even though the commit with the typo is
644 reachable from some other ref, the typo won't really be removed. What will
645 happen instead is that the new version without the typo will ultimately be
646 merged into the other ref(s) (at ``tg update`` time) likely causing a conflict
647 that will have to be manually resolved and the commit with the typo will
648 continue to be reachable from those other refs!
650 Instead just make a new commit to fix the typo. The end result will end up
651 being the same but without the merge conflicts.
653 See also the discussion in the `NO UNDO`_ section.
656 BARE BRANCHES
657 -------------
659 A "TopGit bare branch" (or just "bare branch" for short), refers to a TopGit
660 branch that has neither a ``.topdeps`` nor a ``.topmsg`` file stored in it.
661 And it's neither a new, still-empty empty branch nor an annihilated branch.
663 Such branches are not recommended but are reluctantly accomodated.
665 There are three situtations in which TopGit may encounter a TopGit branch
666 that has neither a ``.topdeps`` nor a ``.topmsg`` file.
668 1. Branch creation with ``--no-commit``
669 Before the initial commit is made, the branch will still be
670 pointing to the same commit as its "top-bases" ref. Branches
671 in this condition (where the branch and top-bases ref point to
672 the same commit) show up as having "No commits" in listings.
674 2. Annihilated branches
675 A branch is annihilated by making a new commit on the branch
676 that makes its tree identical to the tree of its corresponding
677 top-bases ref. Although the trees will be the same, the
678 commits will be different and annihilated branches are
679 distinguished from "No commits" branches in this way.
680 Annihilated branches are generally invisible and do not show up
681 in listings or other status displays. Intentionally so.
683 3. Bare branches
684 Any TopGit branch with neither a ``.topdeps`` file nor a
685 ``.topmsg`` file whose branch and top-bases trees differ falls
686 into this category. TopGit will not create such a branch
687 itself nor does it provide any commands to do so.
689 Whenever possible, a TopGit "[BASE]" branch should be preferred to using a
690 "bare branch" because a) it can never be mistaken for an annihilated branch,
691 b) it has a nice subject attached (via its ``.topmsg`` file) that shows
692 up in listings and c) exactly when and which updates are taken can be planned.
694 Nevertheless, situations may arise where it's useful to have TopGit treat a
695 branch as a "TopGit branch" so that it fully participates in all update
696 activities (such as updating local branches based on their remote branches),
697 but it's not feasible to turn it into a real "TopGit branch" as it comes from
698 an external source and rather than controlling exactly when and what updates
699 are picked up from it by TopGit (the precise use case of a "[BASE]" branch),
700 all updates that appear on it are to be assimilated as soon as they occur.
702 For this reason, TopGit will accomodate such "bare branches" but it will not
703 create (nor provide the means to create) them itself.
705 In order to create a "bare branch" all that's required is to create the
706 necessary top-bases ref. The choice of commit for the top-bases ref will
707 affect the output of the "files", "log" and "patch" commands most directly
708 (but all commands will be affected).
710 To work properly as a "bare branch", the commit the "bare branch"'s base points
711 to should be contained within the branch, be a different commit than the branch
712 tip itself and have a different tree than the branch tip. Simply setting the
713 base to the parent commit of the "bare branch" will usually work, but should
714 that commit at the tip of the "bare branch" end up getting reverted as the next
715 commit, the trees would match and it would appear to be an annihilated branch
716 rather than a "bare branch". That is one of the reasons these branches are not
717 recommended in the first place.
719 Setting the base to the root commit of the branch is more reliable and may
720 be accomplished like so for a local branch named "mybranch":
722 ::
724 git update-ref $(tg --top-bases)/mybranch \
725 $(git rev-list --first-parent --max-parents=0 mybranch) ""
727 Typically though it's more likely a remote bare branch will be needed. For
728 a remote named "origin" and a remote branch name of "vendor" this will do it:
730 ::
732 git update-ref $(tg --top-bases -r origin)/vendor \
733 $(git rev-list --first-parent --max-parents=0 origin/vendor) ""
735 Such "bare branches" are not likely ever to receive any more direct support in
736 TopGit than acknowleging they can be useful in some situations and tolerating
737 their existence by functioning properly with them even to the point of the
738 ``pre-commit`` hook tacitly allowing continued commits on such branches without
739 complaints about missing ``.topdeps`` and ``.topmsg`` files.
741 Note, however, that creating a regular TopGit branch that has no changes of its
742 own with the "bare branch" as its single dependency provides a means to supply
743 some kind of documentation if all other uses of the "bare branch" depend on
744 this "wrapper" branch instead of directly on the "bare branch".
747 SPEED AND CACHING
748 -----------------
750 TopGit needs to check many things to determine whether a TopGit branch is
751 up-to-date or not. This can involve a LOT of git commands for a complex
752 dependency tree. In order to speed things up, TopGit keeps a cache of results
753 in a ``tg-cache`` subdirectory in the ``.git`` directory.
755 Results are tagged with the original hash values used to get that result so
756 that items which have not been changed return their results quickly and items
757 which have been changed compute their new result and cache it for future use.
759 The ``.git/tg-cache`` directory may be removed at any time and the cache will
760 simply be recreated in an on-demand fashion as needed, at some speed penalty,
761 until it's fully rebuilt.
763 To force the cache to be fully pre-loaded, run the ``tg summary`` command
764 without any arguments. Otherwise, normal day-to-day TopGit operations should
765 keep it more-or-less up-to-date.
767 While each TopGit command is running, it uses a temporary subdirectory also
768 located in the ``.git`` directory. These directories are named
769 ``tg-tmp.XXXXXX`` where the ``XXXXXX`` part will be random letters and digits.
771 These temporary directories should always be removed automatically after each
772 TopGit command finishes running. As long as you are not in a subshell as a
773 result of a TopGit command stopping and waiting for a manual merge resolution,
774 it's safe to remove any of these directories that may have somehow accidentally
775 been left behind as a result of some failure that occurred while running a
776 TopGit command (provided, of course, it's not actually being used by a TopGit
777 command currently running in another terminal window or by another user on the
778 same repository).
781 USAGE
782 -----
783 ``tg [global options] <subcommand> [<subcommand option/argument>...]``
785 Global options:
787 ``[-C <dir>]... [-r <remote> | -u] [-c <name>=<val>]... [--no-pager]``
789 -C <dir> Change directory to <dir> before doing anything more
790 -r <remote> Pretend ``topgit.remote`` is set to <remote>
791 -u Pretend ``topgit.remote`` is not set
792 -c <name=val> Pass config option to git, may be repeated
793 --no-pager Disable use of any pager (by both TopGit and Git)
794 --top-bases Show full ``top-bases`` ref prefix and exit
795 --exec-path Show path to subcommand scripts location and exit
796 --help Show brief usage help and exit (aka ``-h``)
798 The ``tg`` tool has several subcommands:
800 :`tg annihilate`_: Mark a TopGit-controlled branch as defunct
801 :`tg base`_: Show base commit for one or more TopGit branches
802 :`tg checkout`_: Shortcut for git checkout with name matching
803 :`tg contains`_: Which TopGit-controlled branch contains the commit
804 :`tg create`_: Create a new TopGit-controlled branch
805 :`tg delete`_: Delete a TopGit-controlled branch cleanly
806 :`tg depend`_: Add a new dependency to a TopGit-controlled branch
807 :`tg export`_: Export TopGit branch patches to files or a branch
808 :`tg files`_: Show files changed by a TopGit branch
809 :`tg help`_: Show TopGit help optionally using a browser
810 :`tg import`_: Import commit(s) to separate TopGit branches
811 :`tg info`_: Show status information about a TopGit branch
812 :`tg log`_: Run git log limiting revisions to a TopGit branch
813 :`tg mail`_: Shortcut for git send-email with ``tg patch`` output
814 :`tg migrate-bases`_: Transition top-bases to new location
815 :`tg next`_: Show branches directly depending on a TopGit branch
816 :`tg patch`_: Generate a patch file for a TopGit branch
817 :`tg prev`_: Show non-annihilated TopGit dependencies for a branch
818 :`tg push`_: Run git push on TopGit branch(es) and depedencies
819 :`tg rebase`_: Auto continue git rebase if rerere resolves conflicts
820 :`tg remote`_: Set up remote for fetching/pushing TopGit branches
821 :`tg revert`_: Revert ref(s) to a state stored in a ``tg tag``
822 :`tg status`_: Show current TopGit status (e.g. in-progress update)
823 :`tg summary`_: Show various information about TopGit branches
824 :`tg tag`_: Create tag that records current TopGit branch state
825 :`tg update`_: Update TopGit branch(es) with respect to dependencies
827 tg help
828 ~~~~~~~
829 Our sophisticated integrated help facility. Mostly duplicates
830 what is below::
832 # to list commands:
833 $ tg help
834 # to get help for a particular command:
835 $ tg help <command>
836 # to get help for a particular command in a browser window:
837 $ tg help -w <command>
838 # to get help on TopGit itself
839 $ tg help tg
840 # to get help on TopGit itself in a browser
841 $ tg help -w tg
843 tg status
844 ~~~~~~~~~
845 Our sophisticated status facility. Similar to Git's status command
846 but shows any in-progress update that's awaiting a merge resolution
847 or any other on-going TopGit activity (such as a branch creation).
849 With a single ``--verbose`` (or ``-v``) option include a short status
850 display for any dirty (but not untracked) files. This also causes all
851 non file status lines to be prefixed with "## ".
853 With two (or more) ``--verbose`` (or ``-v``) options, additionally
854 show full symbolic ref names and unabbreviated hash values.
856 With the ``--exit-code`` option the exit code will be non-zero if any
857 TopGit or Git operation is currently in progress or the working
858 tree is unclean.
860 tg create
861 ~~~~~~~~~
862 Create a new TopGit-controlled topic branch of the given name
863 (required argument) and switch to it. If no dependencies are
864 specified (by extra arguments passed after the first one), the
865 current branch is assumed to be the only dependency.
867 By default ``tg create`` opens an editor on the new ``.topmsg`` file
868 and then commits the new ``.topmsg`` and ``.topdeps`` files
869 automatically with a suitable default commit message.
871 The commit message can be changed with the ``-m`` (or ``--message``) or
872 ``-F`` (or ``--file``) option. The automatic commit can be suppressed
873 by using the ``--no-ccmmit`` (or ``-n``) option. Running the editor on
874 the new ``.topmsg`` file can be suppressed by using ```--no-edit``
875 (which does *NOT* suppress the automatic commit unless ``--no-commit``
876 is also given) or by providing an explicit value for the new
877 ``.topmsg`` file using the ``--topmsg`` or ``--topmsg-file`` option.
878 In any case the ``.topmsg`` content will be automatically reformated to
879 have a ``Subject:`` header line if needed.
881 If the ``format.signoff`` config variable (see ``git help config``)
882 has been set to true then the ``Signed-off-by:`` header line added to
883 the end of the initial version of the ``.topmsg`` file will be
884 uncommented by default. Otherwise it will still be there but will be
885 commented out and will be automatically stripped if no action is taken
886 to remove the comment character.
888 If more than one dependency is listed an automatic ``tg update`` runs
889 after the branch has been created to merge in the additional
890 dependencies and bring the branch up-to-date. This can be suppressed
891 with the ``--no-commit`` option (which also suppresses the initial
892 commit) or the ``--no-update`` option (which allows the initial commit
893 while suppressing only the update operation portion).
895 Previous versions of TopGit behaved as though both the ``--no-edit``
896 and ``--no-commit`` options were always given on the command line.
898 The default behavior has been changed to promote a separation between
899 commits that modify ``.topmsg`` and/or ``.topdeps`` and commits that
900 modify other files. This facilitates cleaner cherry picking and other
901 patch maintenance activities.
903 You should edit the patch description (contained in the ``.topmsg``
904 file) as appropriate. It will already contain some prefilled bits.
905 You can set the ``topgit.to``, ``topgit.cc`` and ``topgit.bcc``
906 git configuration variables (see ``man git-config``) in order to
907 have ``tg create`` add these headers with the given default values
908 to ``.topmsg`` before invoking the editor. If the configuration
909 variable ``topgit.subjectPrefix`` is set its value will be inserted
910 *between* the initial ``[`` and the word ``PATCH`` in the subject
911 line (with a space added before the word ``PATCH`` of course).
913 The main task of ``tg create`` is to set up the topic branch base
914 from the dependencies. This may fail due to merge conflicts if more
915 than one dependency is given. In that case, after you commit the
916 conflict resolution, you should call ``tg update --continue`` to
917 finish merging the dependencies into the new topic branch base.
919 With the ``--base`` (aka ``--no-deps``) option at most one dependency
920 may be listed which may be any valid committish (instead of just
921 refs/heads/...) and the newly created TopGit-controlled branch will
922 have an empty ``.topdeps`` file. This may be desirable in order to
923 create a TopGit-controlled branch that has no changes of its own and
924 serves merely to mark the common dependency that all other
925 TopGit-controlled branches in some set of TopGit-controlled branches
926 depend on. A plain, non-TopGit-controlled branch can be used for the
927 same purpose, but the advantage of a TopGit-controlled branch with no
928 dependencies is that it will be pushed with ``tg push``, it will show
929 up in the ``tg summary`` and ``tg info`` output with the subject from
930 its ``.topmsg`` file thereby documenting what it's for and finally it
931 can be set up with ``tg create -r`` and/or ``tg remote --populate`` to
932 facilitate sharing.
934 For example, ``tg create --base release v2.1`` will create a TopGit-
935 controlled ``release`` branch based off the ``v2.1`` tag that can then
936 be used as a base for creation of other TopGit-controlled branches.
937 Then when the time comes to move the base for an entire set of changes
938 up to ``v2.2`` the command ``tg update --base release v2.2`` can be
939 used followed by ``tg update --all``.
941 Using ``--base`` it's also possible to use ``tg create`` on an
942 unborn branch (omit the dependency name or specify ``HEAD``). The
943 unborn branch itself can be made into the new TopGit branch (rather
944 than being born empty and then having the new TopGit branch based off
945 that) by specifying ``HEAD`` as the new branch's name (which is
946 probably what you normally want to do in this case anyway so you can
947 just run ``tg create --base HEAD`` to accomplish that).
949 In an alternative use case, if ``-r <branch>`` is given instead of a
950 dependency list, the topic branch is created based on the given
951 remote branch. With just ``-r`` the remote branch name is assumed
952 to be the same as the local topic branch being created. Since no
953 new commits are created in this mode (only two refs will be updated)
954 the editor will never be run for this use case. Note that no other
955 options may be combined with ``-r``.
957 The ``--quiet`` (or ``-q``) option suppresses most informational
958 messages.
960 tg delete
961 ~~~~~~~~~
962 Remove a TopGit-controlled topic branch of the given name
963 (required argument). Normally, this command will remove only an
964 empty branch (base == head) without dependents; use ``-f`` to
965 remove a non-empty branch or a branch that is depended upon by
966 another branch.
968 The ``-f`` option is also useful to force removal of a branch's
969 base, if you used ``git branch -D B`` to remove branch B, and then
970 certain TopGit commands complain, because the base of branch B
971 is still there.
973 Normally ``tg delete`` will refuse to delete the current branch.
974 However, giving ``-f`` twice (or more) will force it to do so but it
975 will first detach your HEAD.
977 IMPORTANT: Currently, this command will *NOT* remove the branch
978 from the dependency list in other branches. You need to take
979 care of this *manually*. This is even more complicated in
980 combination with ``-f`` -- in that case, you need to manually
981 unmerge the removed branch's changes from the branches depending
982 on it.
984 The same ``--stash`` and ``--no-stash`` options are accepted with
985 the same exact semantics as for `tg update`_.
987 See also ``tg annihilate``.
989 | TODO: ``-a`` to delete all empty branches, depfix, revert
991 tg annihilate
992 ~~~~~~~~~~~~~
993 Make a commit on the current or given TopGit-controlled topic
994 branch that makes it equal to its base, including the presence or
995 absence of .topmsg and .topdeps. Annihilated branches are not
996 displayed by ``tg summary``, so they effectively get out of your
997 way. However, the branch still exists, and ``tg push`` will
998 push it (except if given the ``-a`` option). This way, you can
999 communicate that the branch is no longer wanted.
1001 When annihilating a branch that has dependents (i.e. branches
1002 that depend on it), those dependents have the dependencies of
1003 the branch being annihilated added to them if they do not already
1004 have them as dependencies. Essentially the DAG is repaired to
1005 skip over the annihilated branch.
1007 Normally, this command will remove only an empty branch
1008 (base == head, except for changes to the .top* files); use
1009 ``-f`` to annihilate a non-empty branch.
1011 After completing the annihilation itself, normally ``tg update``
1012 is run on any modified dependents. Use the ``--no-update`` option
1013 to suppress running ``tg update``.
1015 The same ``--stash`` and ``--no-stash`` options are accepted with
1016 the same exact semantics as for `tg update`_.
1018 tg depend
1019 ~~~~~~~~~
1020 Change the dependencies of a TopGit-controlled topic branch.
1021 This should have several subcommands, but only ``add`` is
1022 supported right now.
1024 The ``add`` subcommand takes an argument naming a topic branch to
1025 be added, adds it to ``.topdeps``, performs a commit and then
1026 updates your topic branch accordingly. If you want to do other
1027 things related to the dependency addition, like adjusting
1028 ``.topmsg``, use the option ``--no-commit``. Adding the
1029 ``--no-update`` (or ``--no-commit``) option will suppress the
1030 ``tg update`` normally performed after committing the change.
1032 It is safe to run ``tg depend add`` in a dirty worktree, but the
1033 normally performed ``tg update`` will be suppressed in that case
1034 (even if neither ``--no-update`` nor ``--no-commit`` is given).
1036 You have enabled ``git rerere`` haven't you?
1038 | TODO: Subcommand for removing dependencies, obviously
1040 tg files
1041 ~~~~~~~~
1042 List files changed by the current or specified topic branch.
1044 Options:
1045 -i list files based on index instead of branch
1046 -w list files based on working tree instead of branch
1048 tg info
1049 ~~~~~~~
1050 Show summary information about the current or specified topic
1051 branch.
1053 Numbers in parenthesis after a branch name such as "(11/3 commits)"
1054 indicate how many commits on the branch (11) and how many of those
1055 are non-merge commits (3).
1057 With ``--verbose`` (or ``-v``) include a list of dependents (i.e. other
1058 branches that depend on this one). Another ``--verbose`` annotates
1059 them with "[needs merge]" if the current tip of branch for which info
1060 is being shown has not yet been merged into the base of the dependent.
1062 Alternatively, if ``--heads`` is used then which of the independent
1063 TopGit branch heads (as output by ``tg summary --topgit-heads``)
1064 logically contains the specified commit (which may be any committish --
1065 defaults to ``HEAD`` if not given). Zero or more results will be
1066 output. Note that "logically" means with regard to the TopGit
1067 dependency relationships as established by the ``.topdeps`` file(s).
1068 It's the answer that would be given when all the TopGit branches are
1069 up-to-date (even though they need not be to use this option) and the
1070 ``git branch --contains`` command is run and the output then filtered
1071 to only those branches that appear in ``tg summary --topgit-heads``.
1072 This computation may require several seconds on complex repositories.
1074 If ``--leaves`` is used then the unique list of leaves of the current
1075 or specified topic branch is shown as one fully-qualified ref per line.
1076 Duplicates are suppressed and a tag name will be used when appropriate.
1077 A "leaf" is any dependency that is either not a TopGit branch or is
1078 the base of a non-annihilated TopGit branch with no non-annihilated
1079 dependencies.
1081 The ``--deps`` option shows non-annihilated TopGit dependencies of the
1082 specified branch (default is ``HEAD``). (It can also be spelled out
1083 as ``--dependencies`` for the pedantically inclined.)
1085 The ``--dependents`` option shows non-annihilated TopGit dependents
1086 (i.e. branches that depend on the specified branch). The default
1087 branch to operate on is again ``HEAD``.
1089 A linearized patch series can only be automatically created for a
1090 TopGit topic branch (including its recursive dependencies) when exactly
1091 one line is output by ``tg info --leaves <topic-branch>``.
1093 With ``--series`` the list of TopGit branches in the order they would
1094 be linearized into a patch series is shown along with the description
1095 of each branch. If branch name passed to ``tg info`` is not the last
1096 branch in the series a marker column will be provided to quickly
1097 locate it in the list. This same option can be used with `tg checkout`_.
1099 Some patches shown in the list may not actually end up introducing any
1100 changes if exported and be therefore end up being omitted. The ``0``
1101 indicator in ``tg summary`` output can help to identify some of these.
1103 The patches shown in the series in the order they are shown form the
1104 basis for the ``tg next`` and ``tg prev`` operations with the first
1105 patch shown being considered the first and so on up to the last.
1107 tg patch
1108 ~~~~~~~~
1109 Generate a patch from the current or specified topic branch.
1110 This means that the diff between the topic branch base and head
1111 (latest commit) is shown, appended to the description found in
1112 the ``.topmsg`` file.
1114 The patch is simply dumped to stdout. In the future, ``tg patch``
1115 will be able to automatically send the patches by mail or save
1116 them to files. (TODO)
1118 Options:
1119 -i base patch generation on index instead of branch
1120 -w base patch generation on working tree instead of branch
1121 --binary pass --binary to ``git diff-tree`` to enable generation
1122 of binary patches
1123 --quiet be quiet (aka ``-q``) about missing and unfixed From:
1124 --from make sure patch has a From: line, if not add one
1125 --from=<a> <a> or Signed-off-by value or ident value; ``git am``
1126 really gets unhappy with patches missing From: lines;
1127 will NOT replace an existing non-empty From: header
1128 --no-from leave all From: lines alone, missing or not (default)
1129 --diff-opt options after the branch name (and an optional ``--``)
1130 are passed directly to ``git diff-tree``
1132 In order to pass a sole explicit ``-w`` through to ``git diff-tree`` it
1133 must be separated from the ``tg`` options by an explicit ``--``.
1134 Or it can be spelled as ``--ignore-all-space`` to distinguuish it from
1135 ``tg``'s ``-w`` option.
1137 If the config variable ``topgit.from`` is set to a boolean it can be
1138 used to enable or disable the ``--from`` option by default. If it's
1139 set to the special value ``quiet`` the ``--quiet`` option is enabled
1140 and From: lines are left alone by default. Any other non-empty value
1141 is taken as a default ``--from=<value>`` option. The ``--no-from``
1142 option will temporarily disable use of the config value.
1144 If additional non-``tg`` options are passed through to
1145 ``git diff-tree`` (other than ``--binary`` which is fully supported)
1146 the resulting ``tg patch`` output may not be appliable.
1148 tg mail
1149 ~~~~~~~
1150 Send a patch from the current or specified topic branch as
1151 email(s).
1153 Takes the patch given on the command line and emails it out.
1154 Destination addresses such as To, Cc and Bcc are taken from the
1155 patch header.
1157 Since it actually boils down to ``git send-email``, please refer
1158 to the documentation for that for details on how to setup email
1159 for git. You can pass arbitrary options to this command through
1160 the ``-s`` parameter, but you must double-quote everything. The
1161 ``-r`` parameter with a msgid can be used to generate in-reply-to
1162 and reference headers to an earlier mail.
1164 WARNING: be careful when using this command. It easily sends
1165 out several mails. You might want to run::
1167 git config sendemail.confirm always
1169 to let ``git send-email`` ask for confirmation before sending any
1170 mail.
1172 Options:
1173 -i base patch generation on index instead of branch
1174 -w base patch generation on working tree instead of branch
1176 | TODO: ``tg mail patchfile`` to mail an already exported patch
1177 | TODO: mailing patch series
1178 | TODO: specifying additional options and addresses on command line
1180 tg remote
1181 ~~~~~~~~~
1182 Register the given remote as TopGit-controlled. This will create
1183 the namespace for the remote branch bases and teach ``git fetch``
1184 to operate on them. However, from TopGit 0.8 onwards you need to
1185 use ``tg push``, or ``git push --mirror``, for pushing
1186 TopGit-controlled branches.
1188 ``tg remote`` takes an optional remote name argument, and an
1189 optional ``--populate`` switch. Use ``--populate`` for your
1190 origin-style remotes: it will seed the local topic branch system
1191 based on the remote topic branches. ``--populate`` will also make
1192 ``tg remote`` automatically fetch the remote, and ``tg update`` look
1193 at branches of this remote for updates by default.
1195 Using ``--populate`` with a remote name causes the ``topgit.remote``
1196 git configuration variable to be set to the given remote name.
1198 tg summary
1199 ~~~~~~~~~~
1200 Show overview of all TopGit-tracked topic branches and their
1201 up-to-date status. With a branch name limit output to that branch.
1202 Using ``--deps-only`` or ``--rdeps`` changes the default from all
1203 related branches to just the current ``HEAD`` branch but using
1204 ``--all`` as the branch name will show results for all branches
1205 instead of ``HEAD``.
1207 ``>``
1208 marks the current topic branch
1210 ``0``
1211 indicates that it introduces no changes of its own
1213 ``l``/``r``
1214 indicates respectively whether it is local-only
1215 or has a remote mate
1217 ``L``/``R``
1218 indicates respectively if it is ahead or out-of-date
1219 with respect to its remote mate
1221 ``D``
1222 indicates that it is out-of-date with respect to its
1223 dependencies
1225 ``!``
1226 indicates that it has missing dependencies [even if
1227 they are recursive ones]
1229 ``B``
1230 indicates that it is out-of-date with respect to
1231 its base
1233 ``*``
1234 indicates it is ahead of (and needs to be merged into)
1235 at least one of its dependents -- only computed when
1236 showing all branches or using the (possibly implied)
1237 ``--with-deps`` option.
1239 This can take a longish time to accurately determine all the
1240 relevant information about each branch; you can pass ``-t`` (or ``-l``
1241 or ``--list``) to get just a terse list of topic branch names quickly.
1242 Also adding ``--verbose`` (or ``-v``) includes the subjects too.
1244 If no options or arguments are passed, the default is not actually to
1245 show ``--all`` branches (that was the default once upon a time).
1246 Instead, the default is essentially ``--with-deps $(tg info --heads)``
1247 with a fallback to ``--all`` if ``tg info`` doesn't give up any heads.
1248 This usually provides a more intuitive result. Explicitly using
1249 ``--all`` will always show all branches (related or not to ``HEAD``).
1251 Passing ``--heads`` shows independent topic branch names and when
1252 combined with ``--rdeps`` behaves as though ``--rdeps`` were run with
1253 the output of ``--heads``.
1255 The ``--heads-independent`` option works just like ``--heads`` except
1256 that it computes the heads using ``git merge-base --independent``
1257 rather than examining the TopGit ``.topdeps`` relationships. If the
1258 TopGit branches are all up-to-date (as shown in ``tg summary``) then
1259 both ``--heads`` and ``--heads-independent`` should compute the same
1260 list of heads (unless some overlapping TopGit branches have been
1261 manually created). If not all the TopGit branches are up-to-date then
1262 the ``--heads-independent`` results may have extra items in it, but
1263 occasionally that's what's needed; usually it's the wrong answer.
1264 (Note that ``--topgit-heads`` is accepted as an alias for ``--heads``
1265 as well.)
1267 Using ``--heads-only`` behaves as though the output of ``--heads`` was
1268 passed as the list of branches along with ``--without-deps``.
1270 Alternatively, you can pass ``--graphviz`` to get a dot-suitable output
1271 for drawing a dependency graph between the topic branches.
1273 You can also use the ``--sort`` option to sort the branches using
1274 a topological sort. This is especially useful if each
1275 TopGit-tracked topic branch depends on a single parent branch,
1276 since it will then print the branches in the dependency order.
1277 In more complex scenarios, a text graph view would be much more
1278 useful, but that has not yet been implemented.
1280 The ``--deps`` option outputs dependency information between
1281 branches in a machine-readable format. Feed this to ``tsort`` to
1282 get the output from --sort.
1284 The ``--deps-only`` option outputs a sorted list of the unique branch
1285 names given on the command line plus all of their recursive
1286 dependencies (subject to ``--exclude`` of course). When
1287 ``--deps-only`` is given the default is to just display information for
1288 ``HEAD``, but that can be changed by using ``--all`` as the branch
1289 name. Each branch name will appear only once in the output no matter
1290 how many times it's visited while tracing the dependency graph or how
1291 many branch names are given on the command line to process.
1293 The ``--rdeps`` option outputs dependency information in an indented
1294 text format that clearly shows all the dependencies and their
1295 relationships to one another. When ``--rdeps`` is given the default is
1296 to just display information for ``HEAD``, but that can be changed by
1297 using ``--all`` as the branch name or by adding the ``--heads`` option.
1298 Note that ``tg summary --rdeps --heads`` can be particularly helpful in
1299 seeing all the TopGit-controlled branches in the repository and their
1300 relationships to one another.
1302 Note that ``--rdeps`` has two flavors. The first (and default) is
1303 ``--rdeps-once`` which only shows the dependencies of a branch when
1304 it's first visited. For example, if D depends on several other
1305 branches perhaps recursively and both branch A and B depend on D, then
1306 whichever of A or B is shown first will show the entire dependency
1307 chain for D underneath it and the other one will just show a line for
1308 D itself. This can make the output a bit more compact without actually
1309 losing any information which is why it's the default. However, using
1310 the ``--rdeps-full`` variant will repeat the full dependency chain
1311 every time it's encountered.
1313 Adding ``--with-deps`` replaces the given list of branches (which will
1314 default to ``HEAD`` if none are given) with the result of running
1315 ``tg summary --deps-only --tgish`` on the list of branches. This can
1316 be helpful in limiting ``tg summary`` output to only the list of given
1317 branches and their dependencies when many TopGit-controlled branches
1318 are present in the repository. When it would be allowed,
1319 ``--with-deps`` is now the default. Use ``--without-deps`` to switch
1320 back to the old behavior.
1322 With ``--exclude branch``, branch can be excluded from the output
1323 meaning it will be skipped and its name will be omitted from any
1324 dependency output. The ``--exclude`` option may be repeated to omit
1325 more than one branch from the output. Limiting the output to a single
1326 branch that has been excluded will result in no output at all.
1328 The ``--tgish-only`` option behaves as though any non-TopGit-controlled
1329 dependencies encountered during processing had been listed after an
1330 ``--exclude`` option.
1332 Note that the branch name can be specified as ``HEAD`` or ``@`` as a
1333 shortcut for the TopGit-controlled branch that ``HEAD`` is a
1334 symbolic ref to. The ``tg summary @`` command can be quite useful.
1336 Options:
1337 -i Use TopGit metadata from the index instead of the branch
1338 -w Use TopGit metadata from the working tree instead of the branch
1340 tg contains
1341 ~~~~~~~~~~~
1342 Search all TopGit-controlled branches (and optionally their remotes)
1343 to find which TopGit-controlled branch contains the specified commit.
1345 This is more than just basic branch containment as provided for by the
1346 ``git branch --contains`` command. While the shown branch name(s)
1347 will, indeed, be one (or more) of those output by the
1348 ``git branch --contains`` command, the result(s) will exclude any
1349 TopGit-controlled branches from the result(s) that have one (or more)
1350 of their TopGit dependencies (either direct or indirect) appearing in
1351 the ``git branch --contains`` output.
1353 Normally the result will be only the one, single TopGit-controlled
1354 branch for which the specified committish appears in the ``tg log``
1355 output for that branch (unless the committish lies outside the
1356 TopGit-controlled portion of the DAG and ``--no-strict`` was used).
1358 Unless ``--annihilated-okay`` (or ``--ann`` or ``--annihilated``) is
1359 used then annihilated branches will be immediately removed from the
1360 ``git branch --contains`` output before doing anything else. This
1361 means a committish that was originally located in a now-annihilated
1362 branch will show up in whatever branch picked up the annihilated
1363 branch's changes (if there is one). This is usually the correct
1364 answer, but occasionally it's not; hence this option. If this option
1365 is used together with ``--verbose`` then annihilated branches will
1366 be shown as "[:annihilated:]".
1368 In other words, if a ``tg patch`` is generated for the found branch
1369 (assuming one was found and a subsequent commit in the same branch
1370 didn't then revert or otherwise back out the change), then that patch
1371 will include the changes introduced by the specified committish
1372 (unless, of course, that committish is outside the TopGit-controlled
1373 portion of the DAG and ``--no-strict`` was given).
1375 This can be very helpful when, for example, a bug is discovered and
1376 then after using ``git bisect`` (or some other tool) to find the
1377 offending commit it's time to commit the fix. But because the
1378 TopGit merging history can be quite complicated and maybe the one
1379 doing the fix wasn't the bug's author (or the author's memory is just
1380 going), it can sometimes be rather tedious to figure out which
1381 TopGit branch the fix belongs in. The ``tg contains`` command can
1382 quickly tell you the answer to that question.
1384 With the ``--remotes`` (or ``-r``) option a TopGit-controlled remote
1385 branch name may be reported as the result but only if there is no
1386 non-remote branch containing the committish (this can only happen
1387 if at least one of the TopGit-controlled local branches are not yet
1388 up-to-date with their remotes).
1390 With the ``--verbose`` option show which TopGit DAG head(s) (one or
1391 more of the TopGit-controlled branch names output by
1392 ``tg summary --heads``) have the result as a dependency (either direct
1393 or indirect). Using this option will noticeably increase running time.
1395 With the default ``--strict`` option, results for which the base of the
1396 TopGit-controlled branch contains the committish will be suppressed.
1397 For example, if the committish was deep-down in the master branch
1398 history somewhere far outside of the TopGit-controlled portion of
1399 the DAG, with ``--no-strict``, whatever TopGit-controlled branch(es)
1400 first picked up history containing that committish will be shown.
1401 While this is a useful result it's usually not the desired result
1402 which is why it's not the default.
1404 To summarize, even with ``--remotes``, remote results are only shown
1405 if there are no non-remote results. Without ``--no-strict`` (because
1406 ``--strict`` is the default) results outside the TopGit-controlled
1407 portion of the DAG are never shown and even with ``--no-strict`` they
1408 will only be shown if there are no ``--strict`` results. Finally,
1409 the TopGit head info shown with ``--verbose`` only ever appears for
1410 local (i.e. not a remote branch) results. Annihilated branches are
1411 never considered possible matches without ``--annihilated-okay``.
1413 tg checkout
1414 ~~~~~~~~~~~
1415 Switch to a topic branch. You can use ``git checkout <branch>``
1416 to get the same effect, but this command helps you navigate
1417 the dependency graph, or allows you to match the topic branch
1418 name using a regular expression, so it can be more convenient.
1420 The ``--branch`` (or ``-b`` or ``--branch=<name>``) option changes
1421 the default starting point from ``HEAD`` to the specified branch.
1423 For the "next" and "previous" commands, the ``<steps>`` value may
1424 be ``--all`` (or ``-a``) to take "As many steps As possible" or
1425 "step ALL the way" or "ALL steps at once" (or make something better
1426 up yourself).
1428 The following subcommands are available:
1430 ``tg checkout next [<steps>]``
1431 Check out a branch that directly
1432 depends on your current branch.
1433 Move ``<steps>`` (default 1) step(s) in
1434 the "next" direction (AKA ``n``).
1436 ``tg checkout prev [<steps>]``
1437 Check out a branch that this branch
1438 directly depends on. Move ``<steps>``
1439 (default 1) step(s) in the "previous"
1440 direction (AKA ``p`` or ``previous``).
1442 ``tg checkout [goto] [--] <pattern>``
1443 Check out a topic branch that
1444 matches ``<pattern>``. ``<pattern>``
1445 is used as a grep ERE pattern to filter
1446 all the topic branches. Both ``goto`` and
1447 ``--`` may be omitted provided ``<pattern>``
1448 is not ``-a``, ``--all``, ``-h``, ``--help``,
1449 ``goto``, ``--``, ``n``, ``next``, ``push``,
1450 ``child``, ``p``, ``prev``, ``previous``,
1451 ``pop``, ``parent`` or ``..``.
1453 ``tg checkout [goto] [--] --series[=<head>]``
1454 Check out a topic branch that belongs to
1455 the current (or ``<head>``) patch series.
1456 A list with descriptions (``tg info --series``)
1457 will be shown to choose from if more than one.
1459 ``tg checkout push [<steps>]``
1460 An alias for ``next``.
1462 ``tg checkout child [<steps>]``
1463 Deprecated alias for ``next``.
1465 ``tg checkout``
1466 Semi-deprecated alias for ``next``.
1468 ``tg checkout pop [<steps>]``
1469 An alias for ``prev``.
1471 ``tg checkout parent [<steps>]``
1472 Deprecated alias for ``prev``.
1474 ``tg checkout .. [<steps>]``
1475 Semi-deprecated alias for ``prev``.
1477 If any of the above commands can find more than one possible
1478 branch to switch to, you will be presented with the matches
1479 and asked to select one of them.
1481 If the ``--ignore-other-worktrees`` (or ``--iow``) option is given and
1482 the current Git version is at least 2.5.0 then the full
1483 ``--ignore-other-worktrees`` option will be passed along to the
1484 ``git checkout`` command when it's run (otherwise the option will be
1485 silently ignored and not passed to Git as it would cause an error).
1487 The ``--force`` (or ``-f``) option, when given, gets passed through to
1488 the ``git checkout`` command.
1490 The ``--merge`` (or ``-m``) option, when given, gets passed through to
1491 the ``git checkout`` command.
1493 The ``--quiet`` (or ``-q``) option, when given, gets passed through to
1494 the ``git checkout`` command.
1496 The ``<pattern>`` of ``tg checkout goto`` is optional. If you don't
1497 supply it, all the available topic branches are listed and you
1498 can select one of them.
1500 Normally, the ``next`` and ``prev`` commands moves one step in
1501 the dependency graph of the topic branches. The ``-a`` option
1502 causes them (and their aliases) to move as far as possible.
1503 That is, ``tg checkout next -a`` moves to a topic branch that
1504 depends (directly or indirectly) on the current branch and
1505 that no other branch depends on. ``tg checkout prev -a``
1506 moves to a topic branch that the current topic branch
1507 depends on (directly or indirectly). If there is more than
1508 one possibility, you will be prompted for your selection.
1510 See also NAVIGATION_.
1512 tg export
1513 ~~~~~~~~~
1514 Export a tidied-up history of the current topic branch and its
1515 dependencies, suitable for feeding upstream. Each topic branch
1516 corresponds to a single commit or patch in the cleaned up
1517 history (corresponding basically exactly to ``tg patch`` output
1518 for the topic branch).
1520 The command has three possible outputs now -- either a Git branch
1521 with the collapsed history, a Git branch with a linearized
1522 history, or a quilt series in new directory.
1524 In the case where you are producing collapsed history in a new
1525 branch, you can use this collapsed structure either for
1526 providing a pull source for upstream, or for further
1527 linearization e.g. for creation of a quilt series using git log::
1529 git log --pretty=email -p --topo-order origin..exported
1531 To better understand the function of ``tg export``, consider this
1532 dependency structure::
1534 origin/master - t/foo/blue - t/foo/red - master
1535 `- t/bar/good <,----------'
1536 `- t/baz ------------'
1538 (where each of the branches may have a hefty history). Then::
1540 master$ tg export for-linus
1542 will create this commit structure on the branch ``for-linus``::
1544 origin/master - t/foo/blue -. merge - t/foo/red -.. merge - master
1545 `- t/bar/good <,-------------------'/
1546 `- t/baz ---------------------'
1548 In this mode, ``tg export`` works on the current topic branch, and
1549 can be called either without an option (in that case,
1550 ``--collapse`` is assumed), or with the ``--collapse`` option, and
1551 with one mandatory argument: the name of the branch where the
1552 exported result will be stored.
1554 When using the linearize mode::
1556 master$ tg export --linearize for-linus
1558 you get a linear history respecting the dependencies of your
1559 patches in a new branch ``for-linus``. The result should be more
1560 or less the same as using quilt mode and then reimporting it
1561 into a Git branch. (More or less because the topological order
1562 can usually be extended in more than one way into a total order,
1563 and the two methods may choose different ones.) The result
1564 might be more appropriate for merging upstream, as it contains
1565 fewer merges.
1567 Note that you might get conflicts during linearization because
1568 the patches are reordered to get a linear history. If linearization
1569 would produce conflicts then using ``--quilt`` will also likely result
1570 in conflicts when the exported quilt series is applied. Since the
1571 ``--quilt`` mode simply runs a series of ``tg patch`` commands to
1572 generate the patches in the exported quilt series and those patches
1573 will end up being applied linearly, the same conflicts that would be
1574 produced by the ``--linearize`` option will then occur at that time.
1576 To avoid conflicts produced by ``--linearize`` (or by applying the
1577 ``--quilt`` output), use the default ``--collapse`` mode and then use
1578 ``tg rebase`` (or ``git rebase -m`` directly) on the collapsed branch
1579 (with a suitable <upstream>) followed by ``git format-patch`` on the
1580 rebased result to produce a conflict-free patch set. A suitable
1581 upstream may be determined with the ``tg info --leaves`` command (if
1582 it outputs more than one line, linearization will be problematic).
1584 You have enabled ``git rerere`` haven't you?
1586 When using the quilt mode::
1588 master$ tg export --quilt for-linus
1590 would create the following directory ``for-linus``::
1592 for-linus/t/foo/blue.diff
1593 for-linus/t/foo/red.diff
1594 for-linus/t/bar/good.diff
1595 for-linus/t/baz.diff
1596 for-linus/series:
1597 t/foo/blue.diff -p1
1598 t/bar/good.diff -p1
1599 t/foo/red.diff -p1
1600 t/baz.diff -p1
1602 With ``--quilt``, you can also pass the ``-b`` parameter followed
1603 by a comma-separated explicit list of branches to export, or
1604 the ``--all`` parameter (which can be shortened to ``-a``) to
1605 export them all. The ``--binary`` option enables producing Git
1606 binary patches. These options are currently only supported
1607 with ``--quilt``.
1609 In ``--quilt`` mode the patches are named like the originating
1610 topgit branch. So usually they end up in subdirectories of the
1611 output directory. With the ``--flatten`` option the names are
1612 mangled so that they end up directly in the output dir (slashes
1613 are replaced with underscores). With the ``--strip[=N]`` option
1614 the first ``N`` subdirectories (all if no ``N`` is given) get
1615 stripped off. Names are always ``--strip``'d before being
1616 ``--flatten``'d. With the option ``--numbered`` (which implies
1617 ``--flatten``) the patch names get a number as prefix to allow
1618 getting the order without consulting the series file, which
1619 eases sending out the patches.
1621 | TODO: Make stripping of non-essential headers configurable
1622 | TODO: Make stripping of [PATCH] and other prefixes configurable
1623 | TODO: ``--mbox`` option to export instead as an mbox file
1624 | TODO: support ``--all`` option in other modes of operation
1625 | TODO: For quilt exporting, export the linearized history created in
1626 a temporary branch--this would allow producing conflict-less
1627 series
1629 tg import
1630 ~~~~~~~~~
1631 Import commits within the given revision range(s) into TopGit,
1632 creating one topic branch per commit. The dependencies are set
1633 up to form a linear sequence starting on your current branch --
1634 or a branch specified by the ``-d`` parameter, if present.
1636 The branch names are auto-guessed from the commit messages and
1637 prefixed by ``t/`` by default; use ``-p <prefix>`` to specify an
1638 alternative prefix (even an empty one).
1640 Each "<range>" must be of the form <rev1>..<rev2> where either
1641 <rev1> or <rev2> can be omitted to mean HEAD. Additionally the
1642 shortcut <rev>^! (see ``git help revisions``) is permitted as a
1643 "<range>" to select the single commit <rev> but only if the
1644 commit <rev> has *exactly* one parent. This is really just a
1645 shortcut for <rev>^..<rev> but somewhat safer since it will fail
1646 if <rev> has other than one parent.
1648 Alternatively, you can use the ``-s NAME`` parameter to specify
1649 the name of the target branch; the command will then take one
1650 more argument describing a *single* commit to import (which may
1651 have any number of parents).
1653 tg update
1654 ~~~~~~~~~
1655 Update the current, specified or all topic branches with respect
1656 to changes in the branches they depend on and remote branches.
1657 This is performed in two phases -- first, changes within the
1658 dependencies are merged to the base, then the base is merged
1659 into the topic branch. The output will guide you on what to do
1660 next in case of conflicts.
1662 You have enabled ``git rerere`` haven't you?
1664 The ``--[no-]auto[-update]`` options together with the
1665 ``topgit.setAutoUpdate`` config item control whether or not TopGit
1666 will automatically temporarily set ``rerere.autoUpdate`` to true while
1667 running ``tg update``. The default is true. Note that this does not
1668 enable Git's ``rerere`` feature, it merely makes it automatically stage
1669 any previously resolved conflicts. The ``rerere.enabled`` setting must
1670 still be separately enabled (i.e. set to ``true``) for the ``rerere``
1671 feature to do anything at all.
1673 Using ``--auto[-update]`` makes ``tg update`` always temporarily set
1674 ``rerere.autoUpdate`` to ``true`` while running ``tg update``. The
1675 ``--no-auto[-update]`` option prevents ``tg update`` from changing the
1676 ``rerere.autoUpdate`` setting, but if ``rerere.autoUpdate`` has already
1677 been enabled in a config file, ``tg update`` never disables it even
1678 with ``--no-auto``. If ``topgit.setAutoUpdate`` is unset or set to
1679 ``true`` then ``tg update`` implicitly does ``--auto``, otherwise it
1680 does ``--no-auto``. An explicit command line ``--[no-]auto[-update]``
1681 option causes the ``topgit.setAutoUpdate`` setting to be ignored.
1683 When both ``rerere.enabled`` and ``rerere.autoUpdate`` are set to true
1684 then ``tg update`` will be able to automatically continue an update
1685 whenever ``git rerere`` resolves all the conflicts during a merge.
1686 This can be such a huge time saver. That's why the default is to have
1687 TopGit automatically set ``rerere.autoUpdate`` to true while
1688 ``tg update`` is running (but remember, unless ``rerere.enabled`` has
1689 been set to ``true`` it won't make any difference).
1691 When ``-a`` (or ``--all``) is specified, updates all topic branches
1692 matched by ``<pattern>``'s (see ``git-for-each-ref(1)`` for details),
1693 or all if no ``<pattern>`` is given. Any topic branches with missing
1694 dependencies will be skipped entirely unless ``--skip-missing`` is
1695 specified.
1697 When ``--skip-missing`` is specified, an attempt is made to update topic
1698 branches with missing dependencies by skipping only the dependencies
1699 that are missing. Caveat utilitor.
1701 When ``--stash`` is specified (or the ``topgit.autostash`` config
1702 value is set to ``true``), a ref stash will be automatically created
1703 just before beginning updates if any are needed. The ``--no-stash``
1704 option may be used to disable a ``topgit.autostash=true`` setting.
1705 See the ``tg tag`` ``--stash`` option for details.
1707 After the update, if a single topic branch was specified, it is
1708 left as the current one; if ``-a`` was specified, it returns to
1709 the branch which was current at the beginning.
1711 If your dependencies are not up-to-date, ``tg update`` will first
1712 recurse into them and update them.
1714 If a remote branch update brings in dependencies on branches
1715 that are not yet instantiated locally, you can either bring in
1716 all the new branches from the remote using ``tg remote
1717 --populate``, or only pick out the missing ones using ``tg create
1718 -r`` (``tg summary`` will point out branches with incomplete
1719 dependencies by showing an ``!`` next to them). TopGit will attempt to
1720 instantiate just the missing ones automatically for you, if possible,
1721 when ``tg update`` merges in the new dependencies from the remote.
1723 Using the alternative ``--base`` mode, ``tg update`` will update
1724 the base of a specified ``[BASE]`` branch (which is a branch created
1725 by ``tg create`` using the ``--base`` option) to the specified
1726 committish (the second argument) and then immediately merge that into
1727 the branch itself using the specified message for the merge commit.
1728 If no message is specified on the command line, an editor will open.
1729 Unless ``--force`` is used the new value for the base must contain
1730 the old value (i.e. be a fast-forward update). This is for safety.
1732 This mode makes updates to ``[BASE]`` branches quick and easy.
1734 | TODO: ``tg update -a -c`` to autoremove (clean) up-to-date branches
1736 tg push
1737 ~~~~~~~
1738 If ``-a`` or ``--all`` was specified, pushes all non-annihilated
1739 TopGit-controlled topic branches, to a remote repository.
1740 Otherwise, pushes the specified topic branches -- or the
1741 current branch, if you don't specify which. By default, the
1742 remote gets all the dependencies (both TopGit-controlled and
1743 non-TopGit-controlled) and bases pushed to it too. If
1744 ``--tgish-only`` was specified, only TopGit-controlled
1745 dependencies will be pushed, and if ``--no-deps`` was specified,
1746 no dependencies at all will be pushed.
1748 The ``--dry-run`` and ``--force`` options are passed directly to
1749 ``git push`` if given.
1751 The remote may be specified with the ``-r`` option. If no remote
1752 was specified, the configured default TopGit remote will be
1753 used.
1755 tg base
1756 ~~~~~~~
1757 Prints the base commit of each of the named topic branches, or
1758 the current branch if no branches are named. Prints an error
1759 message and exits with exit code 1 if the named branch is not
1760 a TopGit branch.
1762 tg log
1763 ~~~~~~
1764 Prints the git log of the named topgit branch -- or the current
1765 branch, if you don't specify a name.
1767 This is really just a convenient shortcut for:
1769 ``git log --first-parent --no-merges $(tg base <name>)..<name>``
1771 where ``<name>`` is the name of the TopGit topic branch (or omitted
1772 for the current branch).
1774 However, if ``<name>`` is a ``[BASE]`` branch the ``--no-merges``
1775 option is omitted.
1777 If ``--compact`` is used then ``git log-compact`` will be used instead
1778 of ``git log``. The ``--command=<git-alias>`` option can be used to
1779 replace "log" with any non-whitespace-containing command alias name,
1780 ``--compact`` is just a shortcut for ``--command=log-compact``. The
1781 ``git-log-compact`` tool may be found on its project page located at:
1783 https://mackyle.github.io/git-log-compact
1785 Note that the ``--compact`` or ``--command=`` option must be used
1786 before any ``--`` or ``git log`` options to be recognized.
1788 NOTE: if you have merged changes from a different repository, this
1789 command might not list all interesting commits.
1791 tg tag
1792 ~~~~~~
1793 Creates a TopGit annotated/signed tag or lists the reflog of one.
1795 A TopGit annotated tag records the current state of one or more TopGit
1796 branches and their dependencies and may be used to revert to the tagged
1797 state at any point in the future.
1799 When reflogs are enabled (the default in a non-bare repository) and
1800 combined with the ``--force`` option a single tag name may be used as a
1801 sort of TopGit branch state stash. The special branch name ``--all``
1802 may be used to tag the state of all current TopGit branches to
1803 facilitate this function and has the side-effect of suppressing the
1804 out-of-date check allowing out-of-date branches to be included.
1806 As a special feature, ``--stash`` may be used as the tag name in which
1807 case ``--all`` is implied if no branch name is listed (instead of the
1808 normal default of ``HEAD``), ``--force`` and ``--no-edit`` (use
1809 ``--edit`` to change that) are automatically activated and the tag will
1810 be saved to ``refs/tgstash`` instead of ``refs/tags/<tagname>``.
1811 The ``--stash`` tag name may also be used with the ``-g``/``--reflog``
1812 option.
1814 The mostly undocumented option ``--allow-outdated`` will bypass the
1815 out-of-date check and is implied when ``--stash`` or ``--all`` is used.
1817 A TopGit annotated/signed tag is simply a Git annotated/signed tag with
1818 a "TOPGIT REFS" section appended to the end of the tag message (and
1819 preceding the signature for signed tags). PEM-style begin and end
1820 lines surround one line per ref where the format of each line is
1821 full-hash SP ref-name. A line will be included for each branch given
1822 on the command line and each ref they depend on either directly or
1823 indirectly.
1825 If more than one TopGit branch is given on the command line, a new
1826 commit will be created that has an empty tree and all of the given
1827 TopGit branches as parents and that commit will be tagged. If a single
1828 TopGit branch is given, then it will be tagged. If the ``--tree``
1829 option is used then it will be used instead of an empty tree (a new
1830 commit will be created if necessary to guarantee the specified tree is
1831 what's in the commit the newly created tag refers to). The argument to
1832 the ``--tree`` option may be any valid treeish.
1834 If exactly one of the branches to be tagged is prefixed with a tilde
1835 (``~``) it will be made the first parent of a consolidation commit if
1836 it is not already the sole commit needing to be tagged. If ``--tree``
1837 is NOT used, its tree will also be used instead of the empty tree for
1838 any new consolidation commit if one is created. Note that if
1839 ``--tree`` is given explicitly it's tree is always used but that does
1840 not in any way affect the choice of first parent. Beware that the
1841 ``~`` may need to be quoted to prevent the shell from misinterpreting
1842 it into something else.
1844 All the options for creating a tag serve the same purpose as their Git
1845 equivalents except for two. The ``--refs`` option suppresses tag
1846 creation entirely and emits the "TOPGIT REFS" section that would have
1847 been included with the tag. If the ``--no-edit`` option is given and
1848 no message is supplied (via the ``-m`` or ``-F`` option) then the
1849 default message created by TopGit will be used without running the
1850 editor.
1852 With ``-g`` or ``--reflog`` show the reflog for a tag. With the
1853 ``--reflog-message`` option the message from the reflog is shown.
1854 With the ``--commit-message`` option the first line of the tag's
1855 message (if the object is a tag) or the commit message (if the object
1856 is a commit) falling back to the reflog message for tree and blob
1857 objects is shown. The default is ``--reflog-message`` unless the
1858 ``--stash`` (``refs/tgstash``) is being shown in which case the default
1859 is then ``--commit-message``. Just add either option explicitly to
1860 override the default.
1862 When showing reflogs, non-tag entries are annotated with their type
1863 unless ``--no-type`` is given.
1865 TopGit tags are created with a reflog if core.logallrefupdates is
1866 enabled (the default for non-bare repositories). Unfortunately Git
1867 is incapable of showing an annotated/signed tag's reflog
1868 (using git log -g) as it will first resolve the tag before checking to
1869 see if it has a reflog. Git can, however, show reflogs for lightweight
1870 tags (using git log -g) just fine but that's not helpful here. Use
1871 ``tg tag`` with the ``-g`` or ``--reflog`` option to see the reflog for
1872 an actual tag object. This also works on non-TopGit annotated/signed
1873 tags as well provided they have a reflog.
1875 The number of entries shown may be limited with the ``-n`` option. If
1876 the tagname is omitted then ``--stash`` is assumed.
1878 The ``--delete`` option is a convenience option that runs the
1879 ``git update-ref -d`` command on the specified tag removing it and its
1880 reflog (if it has one).
1882 The ``--clear`` option clears all but the most recent (the ``@{0}``)
1883 reflog entries from the reflog for the specified tag. It's equivalent
1884 to dropping all the higher numbered reflog entries.
1886 The ``--drop`` option drops the specified reflog entry and requires the
1887 given tagname to have an ``@{n}`` suffix where ``n`` is the reflog
1888 entry number to be dropped. This is really just a convenience option
1889 that runs the appropriate ``git reflog delete`` command.
1891 Note that when combined with ``tg revert``, a tag created by ``tg tag``
1892 can be used to transfer TopGit branches. Simply create the tag, push
1893 it somewhere and then have the recipient run ``tg revert`` to recreate
1894 the TopGit branches. This may be helpful in situations where it's not
1895 feasible to push all the refs corresponding to the TopGit-controlled
1896 branches and their top-bases.
1898 tg rebase
1899 ~~~~~~~~~
1900 Provides a ``git rebase`` rerere auto continue function. It may be
1901 used as a drop-in replacement front-end for ``git rebase -m`` that
1902 automatically continues the rebase when ``git rerere`` information is
1903 sufficient to resolve all conflicts.
1905 You have enabled ``git rerere`` haven't you?
1907 If the ``-m`` or ``--merge`` option is not present then ``tg rebase``
1908 will complain and not do anything.
1910 When ``git rerere`` is enabled, previously resolved conflicts are
1911 remembered and can be automatically staged (see ``rerere.autoUpdate``).
1913 However, even with auto staging, ``git rebase`` still stops and
1914 requires an explicit ``git rebase --continue`` to keep going.
1916 In the case where ``git rebase -m`` is being used to flatten history
1917 (such as after a ``tg export --collapse`` prior to a
1918 ``git format-patch``), there's a good chance all conflicts have already
1919 been resolved during normal merge maintenance operations so there's no
1920 reason ``git rebase`` could not automatically continue, but there's no
1921 option to make it do so.
1923 The ``tg rebase`` command provides a ``git rebase --auto-continue``
1924 function.
1926 All the same rebase options can be used (they are simply passed through
1927 to Git unchanged). However, the ``rerere.autoUpdate`` option is
1928 automatically temporarily enabled while running ``git rebase`` and
1929 should ``git rebase`` stop asking one to resolve and continue, but all
1930 conflicts have already been resolved and staged using rerere
1931 information, then ``git rebase --continue`` will be automatically run.
1933 tg revert
1934 ~~~~~~~~~
1935 Provides the ability to revert one or more TopGit branches and their
1936 dependencies to a previous state contained within a tag created using
1937 the ``tg tag`` command. In addition to the actual revert mode
1938 operation a list mode operation is also provided to examine a tag's ref
1939 contents.
1941 The default mode (``-l`` or ``--list``) shows the state of one or more
1942 of the refs/branches stored in the tag data. When no refs are given on
1943 the command line, all refs in the tag data are shown. With the special
1944 ref name ``--heads`` then the indepedent heads contained in the tag
1945 data are shown. The ``--deps`` option shows the specified refs and all
1946 of their dependencies in a single list with no duplicates. The
1947 ``--rdeps`` option shows a display similar to ``tg summary --rdeps``
1948 for each ref or all TopGit heads if no ref is given on the command
1949 line. The standard ``--no-short``, ``--short=n`` etc. options may be
1950 used to override the default ``--short`` output. With ``--hash`` (or
1951 ``--hash-only``) show only the hash in ``--list`` mode in which case
1952 the default is ``--no-short``. The ``--hash`` option can be used much
1953 like the ``git rev-parse --verify`` command to extract a specific hash
1954 value out of a TopGit tag.
1956 Note that unlike `tg summary`_, here ``--heads`` actually does mean the
1957 ``git merge-base --independent`` heads of the stored refs from the tag
1958 data. To see only the independent TopGit topic branch heads stored in
1959 the tag data use the ``--topgit-heads`` option instead. The default
1960 for the ``--rdeps`` option is ``--topgit-heads`` but ``--heads`` can
1961 be given explicitly to change that. (Note that ``--heads-independent``
1962 is accepted as an alias for ``--heads`` as well.)
1964 The revert mode has three submodes, dry-run mode (``-n`` or
1965 ``--dry-run``), force mode (``-f`` or ``--force``) and interactive mode
1966 (``-i`` or ``--interactive``). If ``--dry-run`` (or ``-n``) is given
1967 no ref updates will actually be performed but what would have been
1968 updated is shown instead. If ``--interactive`` (or ``-i``) is given
1969 then the editor is invoked on an instruction sheet allowing manual
1970 selection of the refs to be updated before proceeding. Since revert is
1971 potentially a destructive operation, at least one of the submodes must
1972 be specified explicitly. If no refs are listed on the command line
1973 then all refs in the tag data are reverted. Otherwise the listed refs
1974 and all of their dependencies (unless ``--no-deps`` is given) are
1975 reverted. Unless ``--no-stash`` is given a new stash will be created
1976 using ``tg tag --stash`` (except, of course, in dry-run mode) just
1977 before actually performing the updates to facilitate recovery from
1978 accidents.
1980 Both modes accept fully-qualified (i.e. starts with ``refs/``) ref
1981 names as well as unqualified names (which will be assumed to be located
1982 under ``refs/heads/``). In revert mode a tgish ref will always have
1983 both its ``refs/heads/`` and ``refs/top-bases/`` values included no
1984 matter how it's listed unless ``--no-deps`` is given and the ref is
1985 fully qualified (i.e. starts with ``refs/``) or one or the other of its
1986 values was removed from the instruction sheet in interactive mode. In
1987 list mode a tgish ref will always have both its ``refs/heads/`` and
1988 ``refs/top-bases/`` values included only when using the ``--deps`` or
1989 ``--rdeps`` options.
1991 The ``--tgish-only`` option excludes non-tgish refs (i.e. refs that do
1992 not have a ``refs/heads/<name>``, ``refs/top-bases/<name>`` pair).
1994 The ``--exclude`` option (which can be repeated) excludes specific
1995 refs. If the name given to ``--exclude`` is not fully-qualified (i.e.
1996 starts with ``refs/``) then it will exclude both members of a tgish ref
1997 pair.
1999 The ``--quiet`` (or ``-q``) option may be used in revert mode to
2000 suppress non-dry-run ref change status messages.
2002 The special tag name ``--stash`` (as well as with ``@{n}`` suffixes)
2003 can be used to refer to ``refs/tgstash``.
2005 The ``tg revert`` command supports tags of tags that contains TopGit
2006 refs. So, for example, if you do this::
2008 tg tag newtag --all
2009 git tag -f -a -m "tag the tag" newtag newtag
2011 Then ``newtag`` will be a tag of a tag containing a ``TOPGIT REFS``
2012 section. ``tg revert`` knows how to dereference the outermost
2013 tag to get to the next (and the next etc.) tag to find the
2014 ``TOPGIT REFS`` section so after the above sequence, the tag ``newtag``
2015 can still be used successfully with ``tg revert``.
2017 NOTE: If HEAD points to a ref that is updated by a revert operation
2018 then NO WARNING whatsoever will be issued, but the index and working
2019 tree will always be left completely untouched (and the reflog for
2020 the pointed-to ref can always be used to find the previous value).
2022 tg prev
2023 ~~~~~~~
2024 Output the "previous" branch(es) in the patch series containing the
2025 current or named branch. The "previous" branch(es) being one step
2026 away by default.
2028 Options:
2029 -i show dependencies based on index instead of branch
2030 -w show dependencies based on working tree instead of branch
2031 -n <steps> take ``<steps>`` "previous" steps (default 1)
2032 --all take as many "previous" steps as possible (aka ``-a``)
2033 --verbose show containing series name(s) (aka ``-v``)
2035 The ``-n`` option may also be given as ``--count`` or ``--count=<n>``.
2037 To list all dependencies of a branch see the ``--deps`` option of
2038 the `tg info`_ command.
2040 See also NAVIGATION_ for full details on "previous" steps.
2042 tg next
2043 ~~~~~~~
2044 Output tne "next" branch(es) in the patch series containing the current
2045 or named branch. The "next" branch(es) being one step away by default.
2047 Options:
2048 -i show dependencies based on index instead of branch
2049 -w show dependencies based on working tree instead of branch
2050 -n <steps> take ``<steps>`` "next" steps (default 1)
2051 --all take as many "next" steps as possible (aka ``-a``)
2052 --verbose show containing series name(s) (aka ``-v``)
2054 The ``-n`` option may also be given as ``--count`` or ``--count=<n>``.
2056 To list all dependents of a branch see the ``--dependents`` option of
2057 the `tg info`_ command.
2059 See also NAVIGATION_ for full details on "next" steps.
2061 tg migrate-bases
2062 ~~~~~~~~~~~~~~~~
2063 Transition top-bases from old location to new location.
2065 Beginning with TopGit release 0.19.4, TopGit has the ability to store
2066 the top-bases refs in either the old ``ref/top-bases/...`` location or
2067 the new ``refs/heads/{top-bases}/...`` location. Starting with TopGit
2068 release 0.20.0, the default is the new location.
2070 By storing the top-bases under heads, Git is less likely to complain
2071 when manipulating them, hosting providers are more likely to provide
2072 access to them and Git prevents them from pointing at anything other
2073 than a commit object. All in all a win for everyone.
2075 TopGit attempts to automatically detect whether the new or old location
2076 is being used for the top-bases and just do the right thing. However,
2077 by explicitly setting the config value ``topgit.top-bases`` to either
2078 ``refs`` for the old location or ``heads`` for the new location the
2079 auto-detection can be bypassed. If no top-bases refs are present in
2080 the repository the default prior to TopGit release 0.20.0 is to use the
2081 old location but starting with TopGit release 0.20.0 the default is to
2082 use the new location.
2084 The ``tg migrate-bases`` command may be used to migrate top-bases refs
2085 from the old location to the new location (or, by using the
2086 undocumented ``--reverse`` option, vice versa).
2088 With few exceptions (``tg create -r`` and ``tg revert``), all top-bases
2089 refs (both local *and* remote refs) are expected to be stored in the
2090 same location (either new or old). A repository's current location for
2091 storing top-bases refs may be shown with the ``tg --top-bases`` command.
2093 TODO: tg rename
2094 ~~~~~~~~~~~~~~~
2096 IMPLEMENTATION
2097 --------------
2099 TopGit stores all the topic branches in the regular ``refs/heads/``
2100 namespace (so we recommend distinguishing them with the ``t/`` prefix).
2101 Apart from that, TopGit also maintains a set of auxiliary refs in
2102 ``refs/top-*``. Currently, only ``refs/top-bases/`` is used, containing the
2103 current *base* of the given topic branch -- this is basically a merge of
2104 all the branches the topic branch depends on; it is updated during ``tg
2105 update`` and then merged to the topic branch, and it is the base of a
2106 patch generated from the topic branch by ``tg patch``.
2108 All the metadata is tracked within the source tree and history of the
2109 topic branch itself, in ``.top*`` files; these files are kept isolated
2110 within the topic branches during TopGit-controlled merges and are of
2111 course omitted during ``tg patch``. The state of these files in base
2112 commits is undefined; look at them only in the topic branches
2113 themselves. Currently, two files are defined:
2115 ``.topmsg``:
2116 Contains the description of the topic branch in a
2117 mail-like format, plus the author information, whatever
2118 Cc headers you choose or the post-three-dashes message.
2119 When mailing out your patch, basically only a few extra
2120 mail headers are inserted and then the patch itself is
2121 appended. Thus, as your patches evolve, you can record
2122 nuances like whether the particular patch should have
2123 To-list / Cc-maintainer or vice-versa and similar
2124 nuances, if your project is into that. ``From`` is
2125 prefilled from your current ``GIT_AUTHOR_IDENT``; other
2126 headers can be prefilled from various optional
2127 ``topgit.*`` git config options.
2129 ``.topdeps``:
2130 Contains the one-per-line list of branches this branch
2131 depends on, pre-seeded by ``tg create``. A (continuously
2132 updated) merge of these branches will be the *base* of
2133 your topic branch.
2135 IMPORTANT: DO NOT EDIT ``.topdeps`` MANUALLY!!! If you do so, you need to
2136 know exactly what you are doing, since this file must stay in sync with
2137 the Git history information, otherwise very bad things will happen.
2139 TopGit also automagically installs a bunch of custom commit-related
2140 hooks that will verify whether you are committing the ``.top*`` files in a
2141 sane state. It will add the hooks to separate files within the ``hooks/``
2142 subdirectory, and merely insert calls to them to the appropriate hooks
2143 and make them executable (but will make sure the original hook's code is
2144 not called if the hook was not executable beforehand).
2146 Another automagically installed piece is a ``.git/info/attributes``
2147 specifier for an ``ours`` merge strategy for the files ``.topmsg`` and
2148 ``.topdeps``, and the (intuitive) ``ours`` merge strategy definition in
2149 ``.git/config``.
2152 REMOTE HANDLING
2153 ---------------
2155 There are two remaining issues with accessing topic branches in remote
2156 repositories:
2158 (i) Referring to remote topic branches from your local repository
2159 (ii) Developing some of the remote topic branches locally
2161 There are two somewhat contradictory design considerations here:
2163 (a) Hacking on multiple independent TopGit remotes in a single
2164 repository
2165 (b) Having a self-contained topic system in local refs space
2167 To us, (a) does not appear to be very convincing, while (b) is quite
2168 desirable for ``git-log topic`` etc. working, and increased conceptual
2169 simplicity.
2171 Thus, we choose to instantiate all the topic branches of given remote
2172 locally; this is performed by ``tg remote --populate``. ``tg update``
2173 will also check if a branch can be updated from its corresponding remote
2174 branch. The logic needs to be somewhat involved if we are to "do the
2175 right thing". First, we update the base, handling the remote branch as
2176 if it was the first dependency; thus, conflict resolutions made in the
2177 remote branch will be carried over to our local base automagically.
2178 Then, the base is merged into the remote branch and the result is merged
2179 to the local branch -- again, to carry over remote conflict resolutions.
2180 In the future, this order might be adjustable on a per-update basis, in
2181 case local changes happen to be diverging more than the remote ones.
2182 (See the details in `The Update Process`_ for more in depth coverage.)
2184 All commands by default refer to the remote that ``tg remote --populate``
2185 was called on the last time (stored in the ``topgit.remote`` git
2186 configuration variable). You can manually run any command with a
2187 different base remote by passing ``-r REMOTE`` *before* the subcommand
2188 name or passing ``-u`` *before* the subcommand to run without one.
2191 TESTING TOPGIT
2192 --------------
2194 Running the TopGit test suite only requires POSIX compatibile utilities (just
2195 a POSIX compatibile ``make`` will do) AND a ``perl`` binary.
2197 It is *not* necessary to install TopGit in order to run the TopGit test suite.
2199 To run the TopGit test suite, simply execute this from the top-level of a
2200 TopGit checkout or expanded release tarball:
2202 ::
2204 make test
2206 Yup, that's it. But you're probably thinking, "Why have a whole section just
2207 to say 'run make test'?" Am I right?
2209 The simple ``make test`` command produces a lot of output and while it is
2210 summarized at the end there's a better way.
2212 Do you have the ``prove`` utility available? You need ``perl`` to run the
2213 tests and ``prove`` comes with ``perl`` so you almost cerainly do.
2215 Try running the tests like so:
2217 ::
2219 make DEFAULT_TEST_TARGET=prove test
2222 (For reference, the default value of ``DEFAULT_TEST_TARGET`` is ``test`` which
2223 can be used to override a setting that's been altered using the instructions
2224 shown later on below.)
2226 If that works (you can interrupt it with ``Ctrl-C``), try this next:
2228 ::
2230 make DEFAULT_TEST_TARGET=prove TESTLIB_PROVE_OPTS="-j 4 --timer" test
2232 If that one works (again, you can interrupt it with ``Ctrl-C``) that may end
2233 up being the keeper for running the tests.
2235 However, if you don't have ``prove`` for some reason even though you do have
2236 ``perl``, there's still an alternative for briefer output. Try this:
2238 ::
2240 make TESTLIB_TEST_OPTS=-q test
2242 Much of the normal testing output will be suppressed and there's still a
2243 summary at the end. If you're stuck with this version but your make supports
2244 parallel operation (the ``-j`` *<n>*) option, then you might try this:
2246 ::
2248 make -j 4 TESTLIB_TEST_OPTS=-q test
2250 If your make *does* support the parallel ``-j`` option but still seems to be
2251 only running one test at a time try it like this instead:
2253 ::
2255 make TESTLIB_MAKE_OPTS="-j 4" TESTLIB_TEST_OPTS=-q test
2257 The difference is that ``make -j 4`` relies on make to properly pass down the
2258 parallel job option all the way down to the sub-make that runs the individual
2259 tests when not using prove. Putting the options in ``TESTLIB_MAKE_OPTS``
2260 passes them directly to that (and only that) particular invocation of make.
2262 The final bit of advice for running the tests is that any of those ``make``
2263 variable settings can be enabled by default in a top-level ``config.mak`` file.
2265 For example, to make the ``prove -j 4 --timer`` (my personal favorite) the
2266 default when running the tests, add these lines (creating the file if it does
2267 not already exist) to the ``config.mak`` file located in the top-level of the
2268 TopGit checkout (or expanded release tarball):
2270 ::
2272 # config.mak file
2273 # comments are allowed (if preceded by '#')
2274 # so are blank lines
2276 DEFAULT_TEST_TARGET = prove
2277 TESTLIB_PROVE_OPTS = -j 4 --timer
2278 #TESTLIB_TEST_OPTS = --color # force colorized test output
2280 Now simply doing ``make test`` will use those options by default.
2282 There is copious documentation on the testing library and other options in
2283 the various ``README`` files located in the ``t`` subdirectory. The
2284 ``Makefile.mak`` file in the ``t`` subdirectory contains plenty of comments
2285 about possible makefile variable settings as well.
2289 TECHNICAL
2290 ---------
2292 A familiarity with the terms in the GLOSSARY_ is helpful for understanding the
2293 content of this sections. See also the IMPLEMENTATION_ section.
2295 The Update Process
2296 ~~~~~~~~~~~~~~~~~~
2298 When a branch is "updated" using the ``tg update`` command the following steps
2299 are taken:
2301 1) The branch and all of its dependencies (and theirs recursively)
2302 are checked to see which ones are *out-of-date*. See glossary_.
2304 2) Each of the branch's direct dependencies (i.e. they are listed in
2305 the branch's ``.topdeps`` file) which is out of date is updated
2306 before proceeding (yup, this is a recursive process).
2308 3) Each of the branch's direct dependencies (i.e. they are listed in
2309 the branch's ``.topdes`` file) that was updated in the previous
2310 step is now merged into the branch's corresponding base. If a
2311 remote is involved, and the branch's corresponding base does NOT
2312 contain the remote branch's corresponding base that remote base is
2313 also merged into the branch's base at this time as well (it will be
2314 the first item merged into the branch's base).
2316 4) If the branch has a corresponding remote branch and the branch
2317 does not already contain it, it's merged into the branch's base
2318 (which was possibly already updated in step (3) to contain the
2319 remote branch's base but not the remote branch itself) on a detached
2320 HEAD. Yup, this step can be a bit confusing and no, the updated
2321 base from step (3) has not yet been merged into the branch itself
2322 yet either. If there is no remote branch this step does not apply.
2323 Using a detached HEAD allows the remote branch to be merged into the
2324 contents of the base without actually perturbing the base's ref.
2326 5) If there is a remote branch present then use the result of step (4)
2327 otherwise use the branch's base and merge that into the branch
2328 itself.
2330 That's it! Simple, right? ;)
2332 Unless the auto stash option has been disabled (see `no undo`_, `tg update`_
2333 and `tg tag`_), a copy of all the old refs values will be stashed away
2334 immediately after step (1) before starting step (2), but only if anything is
2335 actually found to be out-of-date.
2337 Merge Strategies
2338 ~~~~~~~~~~~~~~~~
2340 The ``tg update`` command regularly performs merges while executing an update
2341 operation. In order to speed things up, it attempts to do in-index merges
2342 where possible. It accomplishes this by using a separate, temporary index
2343 file and the ``git read-tree -m --aggressive`` command possibly assisted by
2344 the ``git merge-index`` and ``git merge-file`` commands. This combination may
2345 be repeated more than once to perform an octopus in-index merge. If this
2346 fails, the files are checked out and a normal ``git merge`` three-way merge is
2347 performed (possily multiple times). If the normal ``git merge`` fails then
2348 user intervention is required to resolve the merge conflict(s) and continue.
2350 Since the ``tg annihilate``, ``tg create`` and ``tg depend add`` commands may
2351 end up running the ``tg update`` machinery behind the scenes to complete their
2352 operation they may also result in any of these merge strategies being used.
2354 In addition to the normal Git merge strategies (if the in-index merging fails),
2355 there are four possible TopGit merge strategies that may be shown. Since they
2356 all involve use of the ``git read-tree -m --aggressive`` command they are all
2357 variations of a "trivial aggressive" merge. The "trivial" part because all of
2358 the merges done by ``git read-tree -m`` are described as "trivial" and the
2359 "aggressive" part because the ``--aggressive`` option is always used.
2361 1) "trivial aggressive"
2362 Only two heads were involved and all merging was completed by
2363 the ``git read-tree -m --aggressive`` command.
2365 2) "trivial aggressive automatic"
2366 Only two heads were involved but after the
2367 ``git read-tree -m --aggressive`` command completed there were
2368 still unresolved items and ``git merge-index`` had to be run
2369 (using the ``tg index-merge-one-file`` driver) which ultimately
2370 ran ``git merge-file`` at least once to perform a simple
2371 automatic three-way merge. Hence the "automatic" description
2372 and the "Auto-merging ..." output line(s).
2374 3) "trivial aggressive octopus"
2375 This is the same as a "trivial aggressive" merge except that
2376 more than two heads were involved and after merging the first
2377 two heads, the ``git read-tree -m --aggressive`` step was
2378 repeated again on the result for each additional head. All
2379 merging was completed via multiple
2380 ``git read-tree -m --aggressive`` commands only.
2381 This beast is relatively rare in the wild.
2383 4) "trivial aggressive automatic octopus"
2384 This is very similar to the "trivial aggressive octopus"
2385 except that at least one of the ``git read-tree -m --aggressive``
2386 commands left unresolved items that were handled the same way
2387 as the "trivial aggressive automatic" strategy. This species
2388 is commonly seen in the wild.
2391 GLOSSARY
2392 --------
2394 .topmsg
2395 Version-controlled file stored at the root level of each
2396 TopGit branch that contains the patch header for a TopGit
2397 branch. See also IMPLEMENTATION_;
2399 .topdeps
2400 Version-controlled file stored at the root level of each
2401 TopGit branch that lists the branch's dependencies one per
2402 line omitting the leading ``refs/heads/`` part. See also
2403 IMPLEMENTATION_;
2405 branch containment
2406 Given two Git commit identifiers (e.g. hashes) C1 and C2,
2407 commit C1 "contains" commit C2 if either they are the same
2408 commit or C2 can be reached from C1 by following one or more
2409 parent links from C1 (perhaps via one or more intermediate
2410 commits along the way). In other words, if C1 contains C2
2411 then C2 is an ancestor of C1 or conversely C1 is a descendant
2412 of C2. Since a TopGit branch name is also the name of a Git
2413 branch (something located under the ``refs/heads`` Git
2414 namespace) and similarly for a TopGit base, they can both be
2415 resolved to a Git commit identifier and then participate in
2416 a branch containment test. An easy mnemonic for this is
2417 "children contain the genes of their parents."
2419 BRE pattern
2420 A Basic Regular Expression (BRE) pattern. These are older
2421 style regular expressions but have the advantage that all
2422 characters other than ``\``, ``.``, ``*`` and ``[``
2423 automatically match themselves without need for backslash
2424 quoting (well actually, ``^`` and ``$`` are special at the
2425 beginning and end respectively but otherwise match themselves).
2427 contains
2428 See branch containment.
2430 ERE pattern
2431 An Extended Regular Expression (ERE) pattern. These are newer
2432 style regular expressions where all the regular expression
2433 "operator" characters "operate" when NOT preceded by a
2434 backslash and are turned into normal characters with a ``\``.
2435 The backreference atom, however, may not work, but ``?``, ``+``
2436 and ``|`` "operators" do; unlike BREs.
2438 TopGit
2439 Excellent system for managing a history of changes to one
2440 or more possibly interrelated patches.
2442 TopGit branch
2443 A Git branch that has an associated TopGit base. Conceptually
2444 it represents a single patch that is the difference between
2445 the associated TopGit base and the TopGit branch. In other
2446 words ``git diff-tree <TopGit base> <TopGit branch>`` except
2447 that any ``.topdeps`` and/or ``.topmsg`` files are excluded
2448 from the result and the contents of the ``.topmsg`` file from
2449 the TopGit branch is prefixed to the result.
2451 TopGit bare branch
2452 A Git branch whose tree does NOT contain any `.topdeps` or
2453 `.topmsg` entries at the top-level of the tree. It *does*
2454 always have an associated "TopGit base" ref (otherwise it would
2455 not be a "TopGit" branch). See also `BARE BRANCHES`_.
2457 bare branch
2458 In TopGit context, "bare branch" almost always refers to a
2459 "TopGit bare branch" and should be understood to mean such even
2460 if the leading "TopGit" has been left off.
2462 TopGit base
2463 A Git branch that records the base upon which a TopGit branch's
2464 single conceptual "patch" is built. The name of the Git branch
2465 is derived from the TopGit branch name by stripping off the
2466 leading ``refs/heads/`` and appending the correct prefix where
2467 all TopGit bases are stored (typically either
2468 ``refs/top-bases/`` or ``refs/heads/{top-bases}/`` -- the
2469 prefix for any given repository can be shown by using the
2470 ``tg --top-bases`` command and updated using the
2471 ``tg migrate-bases`` command).
2473 All of a TopGit branch's dependencies are merged into the
2474 corresponding TopGit base during a ``tg update`` of a branch.
2476 base
2477 See TopGit base.
2479 TopGit ``[PATCH]`` branch
2480 A TopGit branch whose subject starts with ``[PATCH]``. By
2481 convention these TopGit branches contain a single patch
2482 (equivalent to a single patch file) and have at least one
2483 dependency (i.e. their ``.topdeps`` files are never empty).
2485 TopGit ``[BASE]`` branch
2486 A TopGit branch whose subject starts with ``[BASE]``. By
2487 convention these TopGit branches do not actually contain
2488 any changes and their ``.topdeps`` files are empty. They
2489 are used to control a base dependency that another set of
2490 branches depends on.
2492 TopGit ``[STAGE]`` branch
2493 A TopGit branch whose subject starts with ``[STAGE]``. By
2494 convention these TopGit branches do not actually contain any
2495 changes of their own but do have one or (typically) more
2496 dependencies in their ``.topdeps`` file. These branches are
2497 used to bring together one or (typically) more independent
2498 TopGit ``[PATCH]`` branches into a single branch so that
2499 testing and/or evaluation can be performed on the result.
2501 merge conflict
2502 When merging two (or more) heads that touch the same lines in
2503 the file but in different ways the result is a merge conflict
2504 that requires manual intervention. If a merge conflict occurs
2505 with more than two heads (an octopus merge) it's generally
2506 replaced by multiple three-way merges so that by the time a
2507 user sees a merge conflict needing manual resolution, there
2508 will be only two heads involved.
2510 merge strategy
2511 A Git merge strategy (see the "MERGE STRATEGIES" section of
2512 ``git help merge``) or one of the TopGit `merge strategies`_
2513 used to merge two or more heads.
2515 TopGit merge strategy
2516 See the `Merge Strategies`_ section above for details but
2517 basically these are just in-index merges done using the
2518 ``git read-tree -m --aggressive`` command one or more times
2519 possibily assisted by the ``git merge-index`` and the
2520 ``git merge-file`` commands.
2522 next branch
2523 In TopGit context the "next" branch refers to the branch that
2524 corresponds to the next (aka following) patch in an ordered
2525 (aka linearized) list of patches created by exporting the
2526 TopGit branches in patch application order.
2528 octopus merge
2529 A merge involving more than two heads. Note that if there are
2530 less than three independent heads the resulting merge that
2531 started out as an octopus will end up not actually being an
2532 octopus after all.
2534 out-of-date branch
2535 A TopGit branch is considered to be "out-of-date" when ANY of
2536 the following are true:
2538 a) The TopGit branch does NOT contain its
2539 corresponding base.
2541 b) The TopGit branch does NOT contain its
2542 corresponding remote branch (there may not be
2543 a remote branch in which case this does not apply)
2545 c) The TopGit branch's base does NOT contain its
2546 corresponding remote branch's base (there may not be
2547 a remote branch in which case this does not apply)
2549 d) Any of the TopGit branches listed in the branch's
2550 ``.topdeps`` file are NOT contained by the branch.
2551 (See "branch containment" above.)
2553 e) Any of the TopGit branches listed in the branch's
2554 ``.topdeps`` file are out-of-date.
2556 Note that if a remote branch is present and is NOT out-of-date
2557 then it will contain its own base and (c) is mostly redundant.
2559 previous branch
2560 In TopGit context the "previous" (or "prev") branch refers to
2561 the branch that corresponds to the previous (aka preceding)
2562 patch in an ordered (aka linearized) list of patches created by
2563 exporting the TopGit branches in patch application order.
2565 remote TopGit branch
2566 A Git branch with the same branch name as a TopGit branch
2567 but living under ``refs/remotes/<some remote>/`` instead
2568 of just ``refs/heads/``.
2570 remote TopGit base
2571 The TopGit base branch corresponding to a remote TopGit branch,
2572 which lives under ``refs/remotes/`` somewhere (depending on
2573 what the output of ``tg --top-bases`` is for that remote).
2575 three-way merge
2576 A three-way merge takes a common base and two heads (call them
2577 A and B) and creates a new file that is the common base plus
2578 all of the changes made between the common base and head A
2579 *AND* all of the changes made between the common base and
2580 head B. The technique used to accomplish this is called a
2581 "merge strategy".
2584 REFERENCES
2585 ----------
2587 The following references are useful to understand the development of
2588 topgit and its subcommands.
2590 * tg depend:
2591 http://public-inbox.org/git/36ca99e90904091034m4d4d31dct78acb333612e678@mail.gmail.com/T/#u
2594 THIRD-PARTY SOFTWARE
2595 --------------------
2597 The following software understands TopGit branches:
2599 * `magit <http://magit.github.io/>`_ -- a git mode for emacs
2601 IMPORTANT: Magit requires its topgit mode to be enabled first, as
2602 described in its documentation, in the "Activating extensions"
2603 subsection. If this is not done, it will not push TopGit branches
2604 correctly, so it's important to enable it even if you plan to mostly use
2605 TopGit from the command line.