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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 --pager Enable use of a pager (aka ``-p``)
795 --top-bases Show full ``top-bases`` ref prefix and exit
796 --exec-path Show path to subcommand scripts location and exit
797 --help Show brief usage help and exit (aka ``-h``)
799 The ``tg`` tool has several subcommands:
801 :`tg annihilate`_: Mark a TopGit-controlled branch as defunct
802 :`tg base`_: Show base commit for one or more TopGit branches
803 :`tg checkout`_: Shortcut for git checkout with name matching
804 :`tg contains`_: Which TopGit-controlled branch contains the commit
805 :`tg create`_: Create a new TopGit-controlled branch
806 :`tg delete`_: Delete a TopGit-controlled branch cleanly
807 :`tg depend`_: Add a new dependency to a TopGit-controlled branch
808 :`tg export`_: Export TopGit branch patches to files or a branch
809 :`tg files`_: Show files changed by a TopGit branch
810 :`tg help`_: Show TopGit help optionally using a browser
811 :`tg import`_: Import commit(s) to separate TopGit branches
812 :`tg info`_: Show status information about a TopGit branch
813 :`tg log`_: Run git log limiting revisions to a TopGit branch
814 :`tg mail`_: Shortcut for git send-email with ``tg patch`` output
815 :`tg migrate-bases`_: Transition top-bases to new location
816 :`tg next`_: Show branches directly depending on a TopGit branch
817 :`tg patch`_: Generate a patch file for a TopGit branch
818 :`tg prev`_: Show non-annihilated TopGit dependencies for a branch
819 :`tg push`_: Run git push on TopGit branch(es) and depedencies
820 :`tg rebase`_: Auto continue git rebase if rerere resolves conflicts
821 :`tg remote`_: Set up remote for fetching/pushing TopGit branches
822 :`tg revert`_: Revert ref(s) to a state stored in a ``tg tag``
823 :`tg status`_: Show current TopGit status (e.g. in-progress update)
824 :`tg summary`_: Show various information about TopGit branches
825 :`tg tag`_: Create tag that records current TopGit branch state
826 :`tg update`_: Update TopGit branch(es) with respect to dependencies
828 tg help
829 ~~~~~~~
830 Our sophisticated integrated help facility. Mostly duplicates
831 what is below::
833 # to list commands:
834 $ tg help
835 # to get help for a particular command:
836 $ tg help <command>
837 # to get help for a particular command in a browser window:
838 $ tg help -w <command>
839 # to get help on TopGit itself
840 $ tg help tg
841 # to get help on TopGit itself in a browser
842 $ tg help -w tg
844 tg status
845 ~~~~~~~~~
846 Our sophisticated status facility. Similar to Git's status command
847 but shows any in-progress update that's awaiting a merge resolution
848 or any other on-going TopGit activity (such as a branch creation).
850 With a single ``--verbose`` (or ``-v``) option include a short status
851 display for any dirty (but not untracked) files. This also causes all
852 non file status lines to be prefixed with "## ".
854 With two (or more) ``--verbose`` (or ``-v``) options, additionally
855 show full symbolic ref names and unabbreviated hash values.
857 With the ``--exit-code`` option the exit code will be non-zero if any
858 TopGit or Git operation is currently in progress or the working
859 tree is unclean.
861 tg create
862 ~~~~~~~~~
863 Create a new TopGit-controlled topic branch of the given name
864 (required argument) and switch to it. If no dependencies are
865 specified (by extra arguments passed after the first one), the
866 current branch is assumed to be the only dependency.
868 By default ``tg create`` opens an editor on the new ``.topmsg`` file
869 and then commits the new ``.topmsg`` and ``.topdeps`` files
870 automatically with a suitable default commit message.
872 The commit message can be changed with the ``-m`` (or ``--message``) or
873 ``-F`` (or ``--file``) option. The automatic commit can be suppressed
874 by using the ``--no-ccmmit`` (or ``-n``) option. Running the editor on
875 the new ``.topmsg`` file can be suppressed by using ```--no-edit``
876 (which does *NOT* suppress the automatic commit unless ``--no-commit``
877 is also given) or by providing an explicit value for the new
878 ``.topmsg`` file using the ``--topmsg`` or ``--topmsg-file`` option.
879 In any case the ``.topmsg`` content will be automatically reformated to
880 have a ``Subject:`` header line if needed.
882 If the ``format.signoff`` config variable (see ``git help config``)
883 has been set to true then the ``Signed-off-by:`` header line added to
884 the end of the initial version of the ``.topmsg`` file will be
885 uncommented by default. Otherwise it will still be there but will be
886 commented out and will be automatically stripped if no action is taken
887 to remove the comment character.
889 If more than one dependency is listed an automatic ``tg update`` runs
890 after the branch has been created to merge in the additional
891 dependencies and bring the branch up-to-date. This can be suppressed
892 with the ``--no-commit`` option (which also suppresses the initial
893 commit) or the ``--no-update`` option (which allows the initial commit
894 while suppressing only the update operation portion).
896 Previous versions of TopGit behaved as though both the ``--no-edit``
897 and ``--no-commit`` options were always given on the command line.
899 The default behavior has been changed to promote a separation between
900 commits that modify ``.topmsg`` and/or ``.topdeps`` and commits that
901 modify other files. This facilitates cleaner cherry picking and other
902 patch maintenance activities.
904 You should edit the patch description (contained in the ``.topmsg``
905 file) as appropriate. It will already contain some prefilled bits.
906 You can set the ``topgit.to``, ``topgit.cc`` and ``topgit.bcc``
907 git configuration variables (see ``man git-config``) in order to
908 have ``tg create`` add these headers with the given default values
909 to ``.topmsg`` before invoking the editor. If the configuration
910 variable ``topgit.subjectPrefix`` is set its value will be inserted
911 *between* the initial ``[`` and the word ``PATCH`` in the subject
912 line (with a space added before the word ``PATCH`` of course).
914 The main task of ``tg create`` is to set up the topic branch base
915 from the dependencies. This may fail due to merge conflicts if more
916 than one dependency is given. In that case, after you commit the
917 conflict resolution, you should call ``tg update --continue`` to
918 finish merging the dependencies into the new topic branch base.
920 With the ``--base`` (aka ``--no-deps``) option at most one dependency
921 may be listed which may be any valid committish (instead of just
922 refs/heads/...) and the newly created TopGit-controlled branch will
923 have an empty ``.topdeps`` file. This may be desirable in order to
924 create a TopGit-controlled branch that has no changes of its own and
925 serves merely to mark the common dependency that all other
926 TopGit-controlled branches in some set of TopGit-controlled branches
927 depend on. A plain, non-TopGit-controlled branch can be used for the
928 same purpose, but the advantage of a TopGit-controlled branch with no
929 dependencies is that it will be pushed with ``tg push``, it will show
930 up in the ``tg summary`` and ``tg info`` output with the subject from
931 its ``.topmsg`` file thereby documenting what it's for and finally it
932 can be set up with ``tg create -r`` and/or ``tg remote --populate`` to
933 facilitate sharing.
935 For example, ``tg create --base release v2.1`` will create a TopGit-
936 controlled ``release`` branch based off the ``v2.1`` tag that can then
937 be used as a base for creation of other TopGit-controlled branches.
938 Then when the time comes to move the base for an entire set of changes
939 up to ``v2.2`` the command ``tg update --base release v2.2`` can be
940 used followed by ``tg update --all``.
942 Using ``--base`` it's also possible to use ``tg create`` on an
943 unborn branch (omit the dependency name or specify ``HEAD``). The
944 unborn branch itself can be made into the new TopGit branch (rather
945 than being born empty and then having the new TopGit branch based off
946 that) by specifying ``HEAD`` as the new branch's name (which is
947 probably what you normally want to do in this case anyway so you can
948 just run ``tg create --base HEAD`` to accomplish that).
950 In an alternative use case, if ``-r <branch>`` is given instead of a
951 dependency list, the topic branch is created based on the given
952 remote branch. With just ``-r`` the remote branch name is assumed
953 to be the same as the local topic branch being created. Since no
954 new commits are created in this mode (only two refs will be updated)
955 the editor will never be run for this use case. Note that no other
956 options may be combined with ``-r``.
958 The ``--quiet`` (or ``-q``) option suppresses most informational
959 messages.
961 tg delete
962 ~~~~~~~~~
963 Remove a TopGit-controlled topic branch of the given name
964 (required argument). Normally, this command will remove only an
965 empty branch (base == head) without dependents; use ``-f`` to
966 remove a non-empty branch or a branch that is depended upon by
967 another branch.
969 The ``-f`` option is also useful to force removal of a branch's
970 base, if you used ``git branch -D B`` to remove branch B, and then
971 certain TopGit commands complain, because the base of branch B
972 is still there.
974 Normally ``tg delete`` will refuse to delete the current branch.
975 However, giving ``-f`` twice (or more) will force it to do so but it
976 will first detach your HEAD.
978 IMPORTANT: Currently, this command will *NOT* remove the branch
979 from the dependency list in other branches. You need to take
980 care of this *manually*. This is even more complicated in
981 combination with ``-f`` -- in that case, you need to manually
982 unmerge the removed branch's changes from the branches depending
983 on it.
985 The same ``--stash`` and ``--no-stash`` options are accepted with
986 the same exact semantics as for `tg update`_.
988 See also ``tg annihilate``.
990 | TODO: ``-a`` to delete all empty branches, depfix, revert
992 tg annihilate
993 ~~~~~~~~~~~~~
994 Make a commit on the current or given TopGit-controlled topic
995 branch that makes it equal to its base, including the presence or
996 absence of .topmsg and .topdeps. Annihilated branches are not
997 displayed by ``tg summary``, so they effectively get out of your
998 way. However, the branch still exists, and ``tg push`` will
999 push it (except if given the ``-a`` option). This way, you can
1000 communicate that the branch is no longer wanted.
1002 When annihilating a branch that has dependents (i.e. branches
1003 that depend on it), those dependents have the dependencies of
1004 the branch being annihilated added to them if they do not already
1005 have them as dependencies. Essentially the DAG is repaired to
1006 skip over the annihilated branch.
1008 Normally, this command will remove only an empty branch
1009 (base == head, except for changes to the .top* files); use
1010 ``-f`` to annihilate a non-empty branch.
1012 After completing the annihilation itself, normally ``tg update``
1013 is run on any modified dependents. Use the ``--no-update`` option
1014 to suppress running ``tg update``.
1016 The same ``--stash`` and ``--no-stash`` options are accepted with
1017 the same exact semantics as for `tg update`_.
1019 tg depend
1020 ~~~~~~~~~
1021 Change the dependencies of a TopGit-controlled topic branch.
1022 This should have several subcommands, but only ``add`` is
1023 supported right now.
1025 The ``add`` subcommand takes an argument naming a topic branch to
1026 be added, adds it to ``.topdeps``, performs a commit and then
1027 updates your topic branch accordingly. If you want to do other
1028 things related to the dependency addition, like adjusting
1029 ``.topmsg``, use the option ``--no-commit``. Adding the
1030 ``--no-update`` (or ``--no-commit``) option will suppress the
1031 ``tg update`` normally performed after committing the change.
1033 It is safe to run ``tg depend add`` in a dirty worktree, but the
1034 normally performed ``tg update`` will be suppressed in that case
1035 (even if neither ``--no-update`` nor ``--no-commit`` is given).
1037 You have enabled ``git rerere`` haven't you?
1039 | TODO: Subcommand for removing dependencies, obviously
1041 tg files
1042 ~~~~~~~~
1043 List files changed by the current or specified topic branch.
1045 Options:
1046 -i list files based on index instead of branch
1047 -w list files based on working tree instead of branch
1049 tg info
1050 ~~~~~~~
1051 Show summary information about the current or specified topic
1052 branch.
1054 Numbers in parenthesis after a branch name such as "(11/3 commits)"
1055 indicate how many commits on the branch (11) and how many of those
1056 are non-merge commits (3).
1058 With ``--verbose`` (or ``-v``) include a list of dependents (i.e. other
1059 branches that depend on this one). Another ``--verbose`` annotates
1060 them with "[needs merge]" if the current tip of branch for which info
1061 is being shown has not yet been merged into the base of the dependent.
1063 Alternatively, if ``--heads`` is used then which of the independent
1064 TopGit branch heads (as output by ``tg summary --topgit-heads``)
1065 logically contains the specified commit (which may be any committish --
1066 defaults to ``HEAD`` if not given). Zero or more results will be
1067 output. Note that "logically" means with regard to the TopGit
1068 dependency relationships as established by the ``.topdeps`` file(s).
1069 It's the answer that would be given when all the TopGit branches are
1070 up-to-date (even though they need not be to use this option) and the
1071 ``git branch --contains`` command is run and the output then filtered
1072 to only those branches that appear in ``tg summary --topgit-heads``.
1073 This computation may require several seconds on complex repositories.
1075 If ``--leaves`` is used then the unique list of leaves of the current
1076 or specified topic branch is shown as one fully-qualified ref per line.
1077 Duplicates are suppressed and a tag name will be used when appropriate.
1078 A "leaf" is any dependency that is either not a TopGit branch or is
1079 the base of a non-annihilated TopGit branch with no non-annihilated
1080 dependencies.
1082 The ``--deps`` option shows non-annihilated TopGit dependencies of the
1083 specified branch (default is ``HEAD``). (It can also be spelled out
1084 as ``--dependencies`` for the pedantically inclined.)
1086 The ``--dependents`` option shows non-annihilated TopGit dependents
1087 (i.e. branches that depend on the specified branch). The default
1088 branch to operate on is again ``HEAD``.
1090 A linearized patch series can only be automatically created for a
1091 TopGit topic branch (including its recursive dependencies) when exactly
1092 one line is output by ``tg info --leaves <topic-branch>``.
1094 With ``--series`` the list of TopGit branches in the order they would
1095 be linearized into a patch series is shown along with the description
1096 of each branch. If branch name passed to ``tg info`` is not the last
1097 branch in the series a marker column will be provided to quickly
1098 locate it in the list. This same option can be used with `tg checkout`_.
1100 Some patches shown in the list may not actually end up introducing any
1101 changes if exported and be therefore end up being omitted. The ``0``
1102 indicator in ``tg summary`` output can help to identify some of these.
1104 The patches shown in the series in the order they are shown form the
1105 basis for the ``tg next`` and ``tg prev`` operations with the first
1106 patch shown being considered the first and so on up to the last.
1108 tg patch
1109 ~~~~~~~~
1110 Generate a patch from the current or specified topic branch.
1111 This means that the diff between the topic branch base and head
1112 (latest commit) is shown, appended to the description found in
1113 the ``.topmsg`` file.
1115 The patch is simply dumped to stdout. In the future, ``tg patch``
1116 will be able to automatically send the patches by mail or save
1117 them to files. (TODO)
1119 Options:
1120 -i base patch generation on index instead of branch
1121 -w base patch generation on working tree instead of branch
1122 --binary pass --binary to ``git diff-tree`` to enable generation
1123 of binary patches
1124 --quiet be quiet (aka ``-q``) about missing and unfixed From:
1125 --from make sure patch has a From: line, if not add one
1126 --from=<a> <a> or Signed-off-by value or ident value; ``git am``
1127 really gets unhappy with patches missing From: lines;
1128 will NOT replace an existing non-empty From: header
1129 --no-from leave all From: lines alone, missing or not (default)
1130 --diff-opt options after the branch name (and an optional ``--``)
1131 are passed directly to ``git diff-tree``
1133 In order to pass a sole explicit ``-w`` through to ``git diff-tree`` it
1134 must be separated from the ``tg`` options by an explicit ``--``.
1135 Or it can be spelled as ``--ignore-all-space`` to distinguuish it from
1136 ``tg``'s ``-w`` option.
1138 If the config variable ``topgit.from`` is set to a boolean it can be
1139 used to enable or disable the ``--from`` option by default. If it's
1140 set to the special value ``quiet`` the ``--quiet`` option is enabled
1141 and From: lines are left alone by default. Any other non-empty value
1142 is taken as a default ``--from=<value>`` option. The ``--no-from``
1143 option will temporarily disable use of the config value.
1145 If additional non-``tg`` options are passed through to
1146 ``git diff-tree`` (other than ``--binary`` which is fully supported)
1147 the resulting ``tg patch`` output may not be appliable.
1149 tg mail
1150 ~~~~~~~
1151 Send a patch from the current or specified topic branch as
1152 email(s).
1154 Takes the patch given on the command line and emails it out.
1155 Destination addresses such as To, Cc and Bcc are taken from the
1156 patch header.
1158 Since it actually boils down to ``git send-email``, please refer
1159 to the documentation for that for details on how to setup email
1160 for git. You can pass arbitrary options to this command through
1161 the ``-s`` parameter, but you must double-quote everything. The
1162 ``-r`` parameter with a msgid can be used to generate in-reply-to
1163 and reference headers to an earlier mail.
1165 WARNING: be careful when using this command. It easily sends
1166 out several mails. You might want to run::
1168 git config sendemail.confirm always
1170 to let ``git send-email`` ask for confirmation before sending any
1171 mail.
1173 Options:
1174 -i base patch generation on index instead of branch
1175 -w base patch generation on working tree instead of branch
1177 | TODO: ``tg mail patchfile`` to mail an already exported patch
1178 | TODO: mailing patch series
1179 | TODO: specifying additional options and addresses on command line
1181 tg remote
1182 ~~~~~~~~~
1183 Register the given remote as TopGit-controlled. This will create
1184 the namespace for the remote branch bases and teach ``git fetch``
1185 to operate on them. However, from TopGit 0.8 onwards you need to
1186 use ``tg push``, or ``git push --mirror``, for pushing
1187 TopGit-controlled branches.
1189 ``tg remote`` takes an optional remote name argument, and an
1190 optional ``--populate`` switch. Use ``--populate`` for your
1191 origin-style remotes: it will seed the local topic branch system
1192 based on the remote topic branches. ``--populate`` will also make
1193 ``tg remote`` automatically fetch the remote, and ``tg update`` look
1194 at branches of this remote for updates by default.
1196 Using ``--populate`` with a remote name causes the ``topgit.remote``
1197 git configuration variable to be set to the given remote name.
1199 tg summary
1200 ~~~~~~~~~~
1201 Show overview of all TopGit-tracked topic branches and their
1202 up-to-date status. With a branch name limit output to that branch.
1203 Using ``--deps-only`` or ``--rdeps`` changes the default from all
1204 branches to just the current ``HEAD`` branch but using ``--all`` as
1205 the branch name will show results for all branches 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.
1243 Adding a second ``--verbose`` includes annihilated branches as well.
1245 Passing ``--heads`` shows independent topic branch names and when
1246 combined with ``--rdeps`` behaves as though ``--rdeps`` were run with
1247 the output of ``--heads``.
1249 The ``--heads-independent`` option works just like ``--heads`` except
1250 that it computes the heads using ``git merge-base --independent``
1251 rather than examining the TopGit ``.topdeps`` relationships. If the
1252 TopGit branches are all up-to-date (as shown in ``tg summary``) then
1253 both ``--heads`` and ``--heads-independent`` should compute the same
1254 list of heads (unless some overlapping TopGit branches have been
1255 manually created). If not all the TopGit branches are up-to-date then
1256 the ``--heads-independent`` results may have extra items in it, but
1257 occasionally that's what's needed; usually it's the wrong answer.
1258 (Note that ``--topgit-heads`` is accepted as an alias for ``--heads``
1259 as well.)
1261 Using ``--heads-only`` behaves as though the output of ``--heads`` was
1262 passed as the list of branches along with ``--without-deps``.
1264 Alternatively, you can pass ``--graphviz`` to get a dot-suitable output
1265 for drawing a dependency graph between the topic branches.
1267 You can also use the ``--sort`` option to sort the branches using
1268 a topological sort. This is especially useful if each
1269 TopGit-tracked topic branch depends on a single parent branch,
1270 since it will then print the branches in the dependency order.
1271 In more complex scenarios, a text graph view would be much more
1272 useful, but that has not yet been implemented.
1274 The ``--deps`` option outputs dependency information between
1275 branches in a machine-readable format. Feed this to ``tsort`` to
1276 get the output from --sort.
1278 The ``--deps-only`` option outputs a sorted list of the unique branch
1279 names given on the command line plus all of their recursive
1280 dependencies (subject to ``--exclude`` of course). When
1281 ``--deps-only`` is given the default is to just display information for
1282 ``HEAD``, but that can be changed by using ``--all`` as the branch
1283 name. Each branch name will appear only once in the output no matter
1284 how many times it's visited while tracing the dependency graph or how
1285 many branch names are given on the command line to process.
1287 The ``--rdeps`` option outputs dependency information in an indented
1288 text format that clearly shows all the dependencies and their
1289 relationships to one another. When ``--rdeps`` is given the default is
1290 to just display information for ``HEAD``, but that can be changed by
1291 using ``--all`` as the branch name or by adding the ``--heads`` option.
1292 Note that ``tg summary --rdeps --heads`` can be particularly helpful in
1293 seeing all the TopGit-controlled branches in the repository and their
1294 relationships to one another.
1296 Note that ``--rdeps`` has two flavors. The first (and default) is
1297 ``--rdeps-once`` which only shows the dependencies of a branch when
1298 it's first visited. For example, if D depends on several other
1299 branches perhaps recursively and both branch A and B depend on D, then
1300 whichever of A or B is shown first will show the entire dependency
1301 chain for D underneath it and the other one will just show a line for
1302 D itself with a "^" appended to indicate that the rest of the deps for
1303 D can be found above. This can make the output a bit more compact
1304 without actually losing any information which is why it's the default.
1305 However, using the ``--rdeps-full`` variant will repeat the full
1306 dependency chain every time it's encountered.
1308 Adding ``--with-deps`` replaces the given list of branches (which will
1309 default to ``HEAD`` if none are given) with the result of running
1310 ``tg summary --deps-only --tgish`` on the list of branches. This can
1311 be helpful in limiting ``tg summary`` output to only the list of given
1312 branches and their dependencies when many TopGit-controlled branches
1313 are present in the repository. Use ``--without-deps`` to switch back
1314 to the old behavior.
1316 The ``--with-related`` option extends (and therefore implies)
1317 ``--with-deps``. First the list of branches (which will default to
1318 ``HEAD`` if none are given) is replaced with the result of running
1319 ``tg summary --heads`` (aka ``--topgit-heads``) and the result is then
1320 processed as though it had been specified using ``--with-deps``.
1322 When it would be allowed, ``--with-deps`` is now the default. But,
1323 if in addition, exactly one branch is specified (either explicitly
1324 or implicitly) and it's spelled *exactly* as ``HEAD`` or ``@`` then
1325 the default ``--with-deps`` will be promoted to a default
1326 ``--with-related`` instead. Since duplicate branches are removed
1327 before processing, explicitly listing ``@`` twice provides an easy way
1328 to defeat this automatic promotion and ask for ``--with-deps`` on the
1329 ``HEAD`` symbolic ref with minimal typing when ``--with-related`` isn't
1330 really wanted and typing the full ``--with-deps`` option is too hard.
1332 With ``--exclude branch``, branch can be excluded from the output
1333 meaning it will be skipped and its name will be omitted from any
1334 dependency output. The ``--exclude`` option may be repeated to omit
1335 more than one branch from the output. Limiting the output to a single
1336 branch that has been excluded will result in no output at all.
1338 The ``--tgish-only`` option behaves as though any non-TopGit-controlled
1339 dependencies encountered during processing had been listed after an
1340 ``--exclude`` option.
1342 Note that the branch name can be specified as ``HEAD`` or ``@`` as a
1343 shortcut for the TopGit-controlled branch that ``HEAD`` is a
1344 symbolic ref to. The ``tg summary @`` and ``tg summary @ @`` commands
1345 can be quite useful.
1347 Options:
1348 -i Use TopGit metadata from the index instead of the branch
1349 -w Use TopGit metadata from the working tree instead of the branch
1351 tg contains
1352 ~~~~~~~~~~~
1353 Search all TopGit-controlled branches (and optionally their remotes)
1354 to find which TopGit-controlled branch contains the specified commit.
1356 This is more than just basic branch containment as provided for by the
1357 ``git branch --contains`` command. While the shown branch name(s)
1358 will, indeed, be one (or more) of those output by the
1359 ``git branch --contains`` command, the result(s) will exclude any
1360 TopGit-controlled branches from the result(s) that have one (or more)
1361 of their TopGit dependencies (either direct or indirect) appearing in
1362 the ``git branch --contains`` output.
1364 Normally the result will be only the one, single TopGit-controlled
1365 branch for which the specified committish appears in the ``tg log``
1366 output for that branch (unless the committish lies outside the
1367 TopGit-controlled portion of the DAG and ``--no-strict`` was used).
1369 Unless ``--annihilated-okay`` (or ``--ann`` or ``--annihilated``) is
1370 used then annihilated branches will be immediately removed from the
1371 ``git branch --contains`` output before doing anything else. This
1372 means a committish that was originally located in a now-annihilated
1373 branch will show up in whatever branch picked up the annihilated
1374 branch's changes (if there is one). This is usually the correct
1375 answer, but occasionally it's not; hence this option. If this option
1376 is used together with ``--verbose`` then annihilated branches will
1377 be shown as "[:annihilated:]".
1379 In other words, if a ``tg patch`` is generated for the found branch
1380 (assuming one was found and a subsequent commit in the same branch
1381 didn't then revert or otherwise back out the change), then that patch
1382 will include the changes introduced by the specified committish
1383 (unless, of course, that committish is outside the TopGit-controlled
1384 portion of the DAG and ``--no-strict`` was given).
1386 This can be very helpful when, for example, a bug is discovered and
1387 then after using ``git bisect`` (or some other tool) to find the
1388 offending commit it's time to commit the fix. But because the
1389 TopGit merging history can be quite complicated and maybe the one
1390 doing the fix wasn't the bug's author (or the author's memory is just
1391 going), it can sometimes be rather tedious to figure out which
1392 TopGit branch the fix belongs in. The ``tg contains`` command can
1393 quickly tell you the answer to that question.
1395 With the ``--remotes`` (or ``-r``) option a TopGit-controlled remote
1396 branch name may be reported as the result but only if there is no
1397 non-remote branch containing the committish (this can only happen
1398 if at least one of the TopGit-controlled local branches are not yet
1399 up-to-date with their remotes).
1401 With the ``--verbose`` option show which TopGit DAG head(s) (one or
1402 more of the TopGit-controlled branch names output by
1403 ``tg summary --heads``) have the result as a dependency (either direct
1404 or indirect). Using this option will noticeably increase running time.
1406 With the default ``--strict`` option, results for which the base of the
1407 TopGit-controlled branch contains the committish will be suppressed.
1408 For example, if the committish was deep-down in the master branch
1409 history somewhere far outside of the TopGit-controlled portion of
1410 the DAG, with ``--no-strict``, whatever TopGit-controlled branch(es)
1411 first picked up history containing that committish will be shown.
1412 While this is a useful result it's usually not the desired result
1413 which is why it's not the default.
1415 To summarize, even with ``--remotes``, remote results are only shown
1416 if there are no non-remote results. Without ``--no-strict`` (because
1417 ``--strict`` is the default) results outside the TopGit-controlled
1418 portion of the DAG are never shown and even with ``--no-strict`` they
1419 will only be shown if there are no ``--strict`` results. Finally,
1420 the TopGit head info shown with ``--verbose`` only ever appears for
1421 local (i.e. not a remote branch) results. Annihilated branches are
1422 never considered possible matches without ``--annihilated-okay``.
1424 tg checkout
1425 ~~~~~~~~~~~
1426 Switch to a topic branch. You can use ``git checkout <branch>``
1427 to get the same effect, but this command helps you navigate
1428 the dependency graph, or allows you to match the topic branch
1429 name using a regular expression, so it can be more convenient.
1431 The ``--branch`` (or ``-b`` or ``--branch=<name>``) option changes
1432 the default starting point from ``HEAD`` to the specified branch.
1434 For the "next" and "previous" commands, the ``<steps>`` value may
1435 be ``--all`` (or ``-a``) to take "As many steps As possible" or
1436 "step ALL the way" or "ALL steps at once" (or make something better
1437 up yourself).
1439 The following subcommands are available:
1441 ``tg checkout next [<steps>]``
1442 Check out a branch that directly
1443 depends on your current branch.
1444 Move ``<steps>`` (default 1) step(s) in
1445 the "next" direction (AKA ``n``).
1447 ``tg checkout prev [<steps>]``
1448 Check out a branch that this branch
1449 directly depends on. Move ``<steps>``
1450 (default 1) step(s) in the "previous"
1451 direction (AKA ``p`` or ``previous``).
1453 ``tg checkout [goto] [--] <pattern>``
1454 Check out a topic branch that
1455 matches ``<pattern>``. ``<pattern>``
1456 is used as a grep ERE pattern to filter
1457 all the topic branches. Both ``goto`` and
1458 ``--`` may be omitted provided ``<pattern>``
1459 is not ``-a``, ``--all``, ``-h``, ``--help``,
1460 ``goto``, ``--``, ``n``, ``next``, ``push``,
1461 ``child``, ``p``, ``prev``, ``previous``,
1462 ``pop``, ``parent`` or ``..``.
1464 ``tg checkout [goto] [--] --series[=<head>]``
1465 Check out a topic branch that belongs to
1466 the current (or ``<head>``) patch series.
1467 A list with descriptions (``tg info --series``)
1468 will be shown to choose from if more than one.
1470 ``tg checkout push [<steps>]``
1471 An alias for ``next``.
1473 ``tg checkout child [<steps>]``
1474 Deprecated alias for ``next``.
1476 ``tg checkout``
1477 Semi-deprecated alias for ``next``.
1479 ``tg checkout pop [<steps>]``
1480 An alias for ``prev``.
1482 ``tg checkout parent [<steps>]``
1483 Deprecated alias for ``prev``.
1485 ``tg checkout .. [<steps>]``
1486 Semi-deprecated alias for ``prev``.
1488 If any of the above commands can find more than one possible
1489 branch to switch to, you will be presented with the matches
1490 and asked to select one of them.
1492 If the ``--ignore-other-worktrees`` (or ``--iow``) option is given and
1493 the current Git version is at least 2.5.0 then the full
1494 ``--ignore-other-worktrees`` option will be passed along to the
1495 ``git checkout`` command when it's run (otherwise the option will be
1496 silently ignored and not passed to Git as it would cause an error).
1498 The ``--force`` (or ``-f``) option, when given, gets passed through to
1499 the ``git checkout`` command.
1501 The ``--merge`` (or ``-m``) option, when given, gets passed through to
1502 the ``git checkout`` command.
1504 The ``--quiet`` (or ``-q``) option, when given, gets passed through to
1505 the ``git checkout`` command.
1507 The ``<pattern>`` of ``tg checkout goto`` is optional. If you don't
1508 supply it, all the available topic branches are listed and you
1509 can select one of them.
1511 Normally, the ``next`` and ``prev`` commands moves one step in
1512 the dependency graph of the topic branches. The ``-a`` option
1513 causes them (and their aliases) to move as far as possible.
1514 That is, ``tg checkout next -a`` moves to a topic branch that
1515 depends (directly or indirectly) on the current branch and
1516 that no other branch depends on. ``tg checkout prev -a``
1517 moves to a topic branch that the current topic branch
1518 depends on (directly or indirectly). If there is more than
1519 one possibility, you will be prompted for your selection.
1521 See also NAVIGATION_.
1523 tg export
1524 ~~~~~~~~~
1525 Export a tidied-up history of the current topic branch and its
1526 dependencies, suitable for feeding upstream. Each topic branch
1527 corresponds to a single commit or patch in the cleaned up
1528 history (corresponding basically exactly to ``tg patch`` output
1529 for the topic branch).
1531 The command has three possible outputs now -- either a Git branch
1532 with the collapsed history, a Git branch with a linearized
1533 history, or a quilt series in new directory.
1535 In the case where you are producing collapsed history in a new
1536 branch, you can use this collapsed structure either for
1537 providing a pull source for upstream, or for further
1538 linearization e.g. for creation of a quilt series using git log::
1540 git log --pretty=email -p --topo-order origin..exported
1542 To better understand the function of ``tg export``, consider this
1543 dependency structure::
1545 origin/master - t/foo/blue - t/foo/red - master
1546 `- t/bar/good <,----------'
1547 `- t/baz ------------'
1549 (where each of the branches may have a hefty history). Then::
1551 master$ tg export for-linus
1553 will create this commit structure on the branch ``for-linus``::
1555 origin/master - t/foo/blue -. merge - t/foo/red -.. merge - master
1556 `- t/bar/good <,-------------------'/
1557 `- t/baz ---------------------'
1559 In this mode, ``tg export`` works on the current topic branch, and
1560 can be called either without an option (in that case,
1561 ``--collapse`` is assumed), or with the ``--collapse`` option, and
1562 with one mandatory argument: the name of the branch where the
1563 exported result will be stored.
1565 When using the linearize mode::
1567 master$ tg export --linearize for-linus
1569 you get a linear history respecting the dependencies of your
1570 patches in a new branch ``for-linus``. The result should be more
1571 or less the same as using quilt mode and then reimporting it
1572 into a Git branch. (More or less because the topological order
1573 can usually be extended in more than one way into a total order,
1574 and the two methods may choose different ones.) The result
1575 might be more appropriate for merging upstream, as it contains
1576 fewer merges.
1578 Note that you might get conflicts during linearization because
1579 the patches are reordered to get a linear history. If linearization
1580 would produce conflicts then using ``--quilt`` will also likely result
1581 in conflicts when the exported quilt series is applied. Since the
1582 ``--quilt`` mode simply runs a series of ``tg patch`` commands to
1583 generate the patches in the exported quilt series and those patches
1584 will end up being applied linearly, the same conflicts that would be
1585 produced by the ``--linearize`` option will then occur at that time.
1587 To avoid conflicts produced by ``--linearize`` (or by applying the
1588 ``--quilt`` output), use the default ``--collapse`` mode and then use
1589 ``tg rebase`` (or ``git rebase -m`` directly) on the collapsed branch
1590 (with a suitable <upstream>) followed by ``git format-patch`` on the
1591 rebased result to produce a conflict-free patch set. A suitable
1592 upstream may be determined with the ``tg info --leaves`` command (if
1593 it outputs more than one line, linearization will be problematic).
1595 You have enabled ``git rerere`` haven't you?
1597 When using the quilt mode::
1599 master$ tg export --quilt for-linus
1601 would create the following directory ``for-linus``::
1603 for-linus/t/foo/blue.diff
1604 for-linus/t/foo/red.diff
1605 for-linus/t/bar/good.diff
1606 for-linus/t/baz.diff
1607 for-linus/series:
1608 t/foo/blue.diff -p1
1609 t/bar/good.diff -p1
1610 t/foo/red.diff -p1
1611 t/baz.diff -p1
1613 With ``--quilt``, you can also pass the ``-b`` parameter followed
1614 by a comma-separated explicit list of branches to export, or
1615 the ``--all`` parameter (which can be shortened to ``-a``) to
1616 export them all. The ``--binary`` option enables producing Git
1617 binary patches. These options are currently only supported
1618 with ``--quilt``.
1620 In ``--quilt`` mode the patches are named like the originating
1621 topgit branch. So usually they end up in subdirectories of the
1622 output directory. With the ``--flatten`` option the names are
1623 mangled so that they end up directly in the output dir (slashes
1624 are replaced with underscores). With the ``--strip[=N]`` option
1625 the first ``N`` subdirectories (all if no ``N`` is given) get
1626 stripped off. Names are always ``--strip``'d before being
1627 ``--flatten``'d. With the option ``--numbered`` (which implies
1628 ``--flatten``) the patch names get a number as prefix to allow
1629 getting the order without consulting the series file, which
1630 eases sending out the patches.
1632 | TODO: Make stripping of non-essential headers configurable
1633 | TODO: Make stripping of [PATCH] and other prefixes configurable
1634 | TODO: ``--mbox`` option to export instead as an mbox file
1635 | TODO: support ``--all`` option in other modes of operation
1636 | TODO: For quilt exporting, export the linearized history created in
1637 a temporary branch--this would allow producing conflict-less
1638 series
1640 tg import
1641 ~~~~~~~~~
1642 Import commits within the given revision range(s) into TopGit,
1643 creating one topic branch per commit. The dependencies are set
1644 up to form a linear sequence starting on your current branch --
1645 or a branch specified by the ``-d`` parameter, if present.
1647 The branch names are auto-guessed from the commit messages and
1648 prefixed by ``t/`` by default; use ``-p <prefix>`` to specify an
1649 alternative prefix (even an empty one).
1651 Each "<range>" must be of the form <rev1>..<rev2> where either
1652 <rev1> or <rev2> can be omitted to mean HEAD. Additionally the
1653 shortcut <rev>^! (see ``git help revisions``) is permitted as a
1654 "<range>" to select the single commit <rev> but only if the
1655 commit <rev> has *exactly* one parent. This is really just a
1656 shortcut for <rev>^..<rev> but somewhat safer since it will fail
1657 if <rev> has other than one parent.
1659 Alternatively, you can use the ``-s NAME`` parameter to specify
1660 the name of the target branch; the command will then take one
1661 more argument describing a *single* commit to import (which may
1662 have any number of parents).
1664 tg update
1665 ~~~~~~~~~
1666 Update the current, specified or all topic branches with respect
1667 to changes in the branches they depend on and remote branches.
1668 This is performed in two phases -- first, changes within the
1669 dependencies are merged to the base, then the base is merged
1670 into the topic branch. The output will guide you on what to do
1671 next in case of conflicts.
1673 You have enabled ``git rerere`` haven't you?
1675 The ``--[no-]auto[-update]`` options together with the
1676 ``topgit.setAutoUpdate`` config item control whether or not TopGit
1677 will automatically temporarily set ``rerere.autoUpdate`` to true while
1678 running ``tg update``. The default is true. Note that this does not
1679 enable Git's ``rerere`` feature, it merely makes it automatically stage
1680 any previously resolved conflicts. The ``rerere.enabled`` setting must
1681 still be separately enabled (i.e. set to ``true``) for the ``rerere``
1682 feature to do anything at all.
1684 Using ``--auto[-update]`` makes ``tg update`` always temporarily set
1685 ``rerere.autoUpdate`` to ``true`` while running ``tg update``. The
1686 ``--no-auto[-update]`` option prevents ``tg update`` from changing the
1687 ``rerere.autoUpdate`` setting, but if ``rerere.autoUpdate`` has already
1688 been enabled in a config file, ``tg update`` never disables it even
1689 with ``--no-auto``. If ``topgit.setAutoUpdate`` is unset or set to
1690 ``true`` then ``tg update`` implicitly does ``--auto``, otherwise it
1691 does ``--no-auto``. An explicit command line ``--[no-]auto[-update]``
1692 option causes the ``topgit.setAutoUpdate`` setting to be ignored.
1694 When both ``rerere.enabled`` and ``rerere.autoUpdate`` are set to true
1695 then ``tg update`` will be able to automatically continue an update
1696 whenever ``git rerere`` resolves all the conflicts during a merge.
1697 This can be such a huge time saver. That's why the default is to have
1698 TopGit automatically set ``rerere.autoUpdate`` to true while
1699 ``tg update`` is running (but remember, unless ``rerere.enabled`` has
1700 been set to ``true`` it won't make any difference).
1702 When ``-a`` (or ``--all``) is specified, updates all topic branches
1703 matched by ``<pattern>``'s (see ``git-for-each-ref(1)`` for details),
1704 or all if no ``<pattern>`` is given. Any topic branches with missing
1705 dependencies will be skipped entirely unless ``--skip-missing`` is
1706 specified.
1708 When ``--skip-missing`` is specified, an attempt is made to update topic
1709 branches with missing dependencies by skipping only the dependencies
1710 that are missing. Caveat utilitor.
1712 When ``--stash`` is specified (or the ``topgit.autostash`` config
1713 value is set to ``true``), a ref stash will be automatically created
1714 just before beginning updates if any are needed. The ``--no-stash``
1715 option may be used to disable a ``topgit.autostash=true`` setting.
1716 See the ``tg tag`` ``--stash`` option for details.
1718 After the update, if a single topic branch was specified, it is
1719 left as the current one; if ``-a`` was specified, it returns to
1720 the branch which was current at the beginning.
1722 If your dependencies are not up-to-date, ``tg update`` will first
1723 recurse into them and update them.
1725 If a remote branch update brings in dependencies on branches
1726 that are not yet instantiated locally, you can either bring in
1727 all the new branches from the remote using ``tg remote
1728 --populate``, or only pick out the missing ones using ``tg create
1729 -r`` (``tg summary`` will point out branches with incomplete
1730 dependencies by showing an ``!`` next to them). TopGit will attempt to
1731 instantiate just the missing ones automatically for you, if possible,
1732 when ``tg update`` merges in the new dependencies from the remote.
1734 Using the alternative ``--base`` mode, ``tg update`` will update
1735 the base of a specified ``[BASE]`` branch (which is a branch created
1736 by ``tg create`` using the ``--base`` option) to the specified
1737 committish (the second argument) and then immediately merge that into
1738 the branch itself using the specified message for the merge commit.
1739 If no message is specified on the command line, an editor will open.
1740 Unless ``--force`` is used the new value for the base must contain
1741 the old value (i.e. be a fast-forward update). This is for safety.
1743 This mode makes updates to ``[BASE]`` branches quick and easy.
1745 | TODO: ``tg update -a -c`` to autoremove (clean) up-to-date branches
1747 tg push
1748 ~~~~~~~
1749 If ``-a`` or ``--all`` was specified, pushes all non-annihilated
1750 TopGit-controlled topic branches, to a remote repository.
1751 Otherwise, pushes the specified topic branches -- or the
1752 current branch, if you don't specify which. By default, the
1753 remote gets all the dependencies (both TopGit-controlled and
1754 non-TopGit-controlled) and bases pushed to it too. If
1755 ``--tgish-only`` was specified, only TopGit-controlled
1756 dependencies will be pushed, and if ``--no-deps`` was specified,
1757 no dependencies at all will be pushed.
1759 The ``--dry-run`` and ``--force`` options are passed directly to
1760 ``git push`` if given.
1762 The remote may be specified with the ``-r`` option. If no remote
1763 was specified, the configured default TopGit remote will be
1764 used.
1766 tg base
1767 ~~~~~~~
1768 Prints the base commit of each of the named topic branches, or
1769 the current branch if no branches are named. Prints an error
1770 message and exits with exit code 1 if the named branch is not
1771 a TopGit branch.
1773 tg log
1774 ~~~~~~
1775 Prints the git log of the named topgit branch -- or the current
1776 branch, if you don't specify a name.
1778 This is really just a convenient shortcut for:
1780 ``git log --first-parent --no-merges $(tg base <name>)..<name>``
1782 where ``<name>`` is the name of the TopGit topic branch (or omitted
1783 for the current branch).
1785 However, if ``<name>`` is a ``[BASE]`` branch the ``--no-merges``
1786 option is omitted.
1788 If ``--compact`` is used then ``git log-compact`` will be used instead
1789 of ``git log``. The ``--command=<git-alias>`` option can be used to
1790 replace "log" with any non-whitespace-containing command alias name,
1791 ``--compact`` is just a shortcut for ``--command=log-compact``. The
1792 ``git-log-compact`` tool may be found on its project page located at:
1794 https://mackyle.github.io/git-log-compact
1796 Note that the ``--compact`` or ``--command=`` option must be used
1797 before any ``--`` or ``git log`` options to be recognized.
1799 NOTE: if you have merged changes from a different repository, this
1800 command might not list all interesting commits.
1802 tg tag
1803 ~~~~~~
1804 Creates a TopGit annotated/signed tag or lists the reflog of one.
1806 A TopGit annotated tag records the current state of one or more TopGit
1807 branches and their dependencies and may be used to revert to the tagged
1808 state at any point in the future.
1810 When reflogs are enabled (the default in a non-bare repository) and
1811 combined with the ``--force`` option a single tag name may be used as a
1812 sort of TopGit branch state stash. The special branch name ``--all``
1813 may be used to tag the state of all current TopGit branches to
1814 facilitate this function and has the side-effect of suppressing the
1815 out-of-date check allowing out-of-date branches to be included.
1817 As a special feature, ``--stash`` may be used as the tag name in which
1818 case ``--all`` is implied if no branch name is listed (instead of the
1819 normal default of ``HEAD``), ``--force`` and ``--no-edit`` (use
1820 ``--edit`` to change that) are automatically activated and the tag will
1821 be saved to ``refs/tgstash`` instead of ``refs/tags/<tagname>``.
1822 The ``--stash`` tag name may also be used with the ``-g``/``--reflog``
1823 option.
1825 The mostly undocumented option ``--allow-outdated`` will bypass the
1826 out-of-date check and is implied when ``--stash`` or ``--all`` is used.
1828 A TopGit annotated/signed tag is simply a Git annotated/signed tag with
1829 a "TOPGIT REFS" section appended to the end of the tag message (and
1830 preceding the signature for signed tags). PEM-style begin and end
1831 lines surround one line per ref where the format of each line is
1832 full-hash SP ref-name. A line will be included for each branch given
1833 on the command line and each ref they depend on either directly or
1834 indirectly.
1836 If more than one TopGit branch is given on the command line, a new
1837 commit will be created that has an empty tree and all of the given
1838 TopGit branches as parents and that commit will be tagged. If a single
1839 TopGit branch is given, then it will be tagged. If the ``--tree``
1840 option is used then it will be used instead of an empty tree (a new
1841 commit will be created if necessary to guarantee the specified tree is
1842 what's in the commit the newly created tag refers to). The argument to
1843 the ``--tree`` option may be any valid treeish.
1845 If exactly one of the branches to be tagged is prefixed with a tilde
1846 (``~``) it will be made the first parent of a consolidation commit if
1847 it is not already the sole commit needing to be tagged. If ``--tree``
1848 is NOT used, its tree will also be used instead of the empty tree for
1849 any new consolidation commit if one is created. Note that if
1850 ``--tree`` is given explicitly it's tree is always used but that does
1851 not in any way affect the choice of first parent. Beware that the
1852 ``~`` may need to be quoted to prevent the shell from misinterpreting
1853 it into something else.
1855 All the options for creating a tag serve the same purpose as their Git
1856 equivalents except for two. The ``--refs`` option suppresses tag
1857 creation entirely and emits the "TOPGIT REFS" section that would have
1858 been included with the tag. If the ``--no-edit`` option is given and
1859 no message is supplied (via the ``-m`` or ``-F`` option) then the
1860 default message created by TopGit will be used without running the
1861 editor.
1863 With ``-g`` or ``--reflog`` show the reflog for a tag. With the
1864 ``--reflog-message`` option the message from the reflog is shown.
1865 With the ``--commit-message`` option the first line of the tag's
1866 message (if the object is a tag) or the commit message (if the object
1867 is a commit) falling back to the reflog message for tree and blob
1868 objects is shown. The default is ``--reflog-message`` unless the
1869 ``--stash`` (``refs/tgstash``) is being shown in which case the default
1870 is then ``--commit-message``. Just add either option explicitly to
1871 override the default.
1873 When showing reflogs, non-tag entries are annotated with their type
1874 unless ``--no-type`` is given.
1876 TopGit tags are created with a reflog if core.logallrefupdates is
1877 enabled (the default for non-bare repositories). Unfortunately Git
1878 is incapable of showing an annotated/signed tag's reflog
1879 (using git log -g) as it will first resolve the tag before checking to
1880 see if it has a reflog. Git can, however, show reflogs for lightweight
1881 tags (using git log -g) just fine but that's not helpful here. Use
1882 ``tg tag`` with the ``-g`` or ``--reflog`` option to see the reflog for
1883 an actual tag object. This also works on non-TopGit annotated/signed
1884 tags as well provided they have a reflog.
1886 The number of entries shown may be limited with the ``-n`` option. If
1887 the tagname is omitted then ``--stash`` is assumed.
1889 The ``--delete`` option is a convenience option that runs the
1890 ``git update-ref -d`` command on the specified tag removing it and its
1891 reflog (if it has one).
1893 The ``--clear`` option clears all but the most recent (the ``@{0}``)
1894 reflog entries from the reflog for the specified tag. It's equivalent
1895 to dropping all the higher numbered reflog entries.
1897 The ``--drop`` option drops the specified reflog entry and requires the
1898 given tagname to have an ``@{n}`` suffix where ``n`` is the reflog
1899 entry number to be dropped. This is really just a convenience option
1900 that runs the appropriate ``git reflog delete`` command.
1902 Note that when combined with ``tg revert``, a tag created by ``tg tag``
1903 can be used to transfer TopGit branches. Simply create the tag, push
1904 it somewhere and then have the recipient run ``tg revert`` to recreate
1905 the TopGit branches. This may be helpful in situations where it's not
1906 feasible to push all the refs corresponding to the TopGit-controlled
1907 branches and their top-bases.
1909 tg rebase
1910 ~~~~~~~~~
1911 Provides a ``git rebase`` rerere auto continue function. It may be
1912 used as a drop-in replacement front-end for ``git rebase -m`` that
1913 automatically continues the rebase when ``git rerere`` information is
1914 sufficient to resolve all conflicts.
1916 You have enabled ``git rerere`` haven't you?
1918 If the ``-m`` or ``--merge`` option is not present then ``tg rebase``
1919 will complain and not do anything.
1921 When ``git rerere`` is enabled, previously resolved conflicts are
1922 remembered and can be automatically staged (see ``rerere.autoUpdate``).
1924 However, even with auto staging, ``git rebase`` still stops and
1925 requires an explicit ``git rebase --continue`` to keep going.
1927 In the case where ``git rebase -m`` is being used to flatten history
1928 (such as after a ``tg export --collapse`` prior to a
1929 ``git format-patch``), there's a good chance all conflicts have already
1930 been resolved during normal merge maintenance operations so there's no
1931 reason ``git rebase`` could not automatically continue, but there's no
1932 option to make it do so.
1934 The ``tg rebase`` command provides a ``git rebase --auto-continue``
1935 function.
1937 All the same rebase options can be used (they are simply passed through
1938 to Git unchanged). However, the ``rerere.autoUpdate`` option is
1939 automatically temporarily enabled while running ``git rebase`` and
1940 should ``git rebase`` stop asking one to resolve and continue, but all
1941 conflicts have already been resolved and staged using rerere
1942 information, then ``git rebase --continue`` will be automatically run.
1944 tg revert
1945 ~~~~~~~~~
1946 Provides the ability to revert one or more TopGit branches and their
1947 dependencies to a previous state contained within a tag created using
1948 the ``tg tag`` command. In addition to the actual revert mode
1949 operation a list mode operation is also provided to examine a tag's ref
1950 contents.
1952 The default mode (``-l`` or ``--list``) shows the state of one or more
1953 of the refs/branches stored in the tag data. When no refs are given on
1954 the command line, all refs in the tag data are shown. With the special
1955 ref name ``--heads`` then the indepedent heads contained in the tag
1956 data are shown. The ``--deps`` option shows the specified refs and all
1957 of their dependencies in a single list with no duplicates. The
1958 ``--rdeps`` option shows a display similar to ``tg summary --rdeps``
1959 for each ref or all TopGit heads if no ref is given on the command
1960 line. The standard ``--no-short``, ``--short=n`` etc. options may be
1961 used to override the default ``--short`` output. With ``--hash`` (or
1962 ``--hash-only``) show only the hash in ``--list`` mode in which case
1963 the default is ``--no-short``. The ``--hash`` option can be used much
1964 like the ``git rev-parse --verify`` command to extract a specific hash
1965 value out of a TopGit tag.
1967 Note that unlike `tg summary`_, here ``--heads`` actually does mean the
1968 ``git merge-base --independent`` heads of the stored refs from the tag
1969 data. To see only the independent TopGit topic branch heads stored in
1970 the tag data use the ``--topgit-heads`` option instead. The default
1971 for the ``--rdeps`` option is ``--topgit-heads`` but ``--heads`` can
1972 be given explicitly to change that. (Note that ``--heads-independent``
1973 is accepted as an alias for ``--heads`` as well.)
1975 The revert mode has three submodes, dry-run mode (``-n`` or
1976 ``--dry-run``), force mode (``-f`` or ``--force``) and interactive mode
1977 (``-i`` or ``--interactive``). If ``--dry-run`` (or ``-n``) is given
1978 no ref updates will actually be performed but what would have been
1979 updated is shown instead. If ``--interactive`` (or ``-i``) is given
1980 then the editor is invoked on an instruction sheet allowing manual
1981 selection of the refs to be updated before proceeding. Since revert is
1982 potentially a destructive operation, at least one of the submodes must
1983 be specified explicitly. If no refs are listed on the command line
1984 then all refs in the tag data are reverted. Otherwise the listed refs
1985 and all of their dependencies (unless ``--no-deps`` is given) are
1986 reverted. Unless ``--no-stash`` is given a new stash will be created
1987 using ``tg tag --stash`` (except, of course, in dry-run mode) just
1988 before actually performing the updates to facilitate recovery from
1989 accidents.
1991 Both modes accept fully-qualified (i.e. starts with ``refs/``) ref
1992 names as well as unqualified names (which will be assumed to be located
1993 under ``refs/heads/``). In revert mode a tgish ref will always have
1994 both its ``refs/heads/`` and ``refs/top-bases/`` values included no
1995 matter how it's listed unless ``--no-deps`` is given and the ref is
1996 fully qualified (i.e. starts with ``refs/``) or one or the other of its
1997 values was removed from the instruction sheet in interactive mode. In
1998 list mode a tgish ref will always have both its ``refs/heads/`` and
1999 ``refs/top-bases/`` values included only when using the ``--deps`` or
2000 ``--rdeps`` options.
2002 The ``--tgish-only`` option excludes non-tgish refs (i.e. refs that do
2003 not have a ``refs/heads/<name>``, ``refs/top-bases/<name>`` pair).
2005 The ``--exclude`` option (which can be repeated) excludes specific
2006 refs. If the name given to ``--exclude`` is not fully-qualified (i.e.
2007 starts with ``refs/``) then it will exclude both members of a tgish ref
2008 pair.
2010 The ``--quiet`` (or ``-q``) option may be used in revert mode to
2011 suppress non-dry-run ref change status messages.
2013 The special tag name ``--stash`` (as well as with ``@{n}`` suffixes)
2014 can be used to refer to ``refs/tgstash``.
2016 The ``tg revert`` command supports tags of tags that contains TopGit
2017 refs. So, for example, if you do this::
2019 tg tag newtag --all
2020 git tag -f -a -m "tag the tag" newtag newtag
2022 Then ``newtag`` will be a tag of a tag containing a ``TOPGIT REFS``
2023 section. ``tg revert`` knows how to dereference the outermost
2024 tag to get to the next (and the next etc.) tag to find the
2025 ``TOPGIT REFS`` section so after the above sequence, the tag ``newtag``
2026 can still be used successfully with ``tg revert``.
2028 NOTE: If HEAD points to a ref that is updated by a revert operation
2029 then NO WARNING whatsoever will be issued, but the index and working
2030 tree will always be left completely untouched (and the reflog for
2031 the pointed-to ref can always be used to find the previous value).
2033 tg prev
2034 ~~~~~~~
2035 Output the "previous" branch(es) in the patch series containing the
2036 current or named branch. The "previous" branch(es) being one step
2037 away by default.
2039 Options:
2040 -i show dependencies based on index instead of branch
2041 -w show dependencies based on working tree instead of branch
2042 -n <steps> take ``<steps>`` "previous" steps (default 1)
2043 --all take as many "previous" steps as possible (aka ``-a``)
2044 --verbose show containing series name(s) (aka ``-v``)
2046 The ``-n`` option may also be given as ``--count`` or ``--count=<n>``.
2048 To list all dependencies of a branch see the ``--deps`` option of
2049 the `tg info`_ command.
2051 See also NAVIGATION_ for full details on "previous" steps.
2053 tg next
2054 ~~~~~~~
2055 Output tne "next" branch(es) in the patch series containing the current
2056 or named branch. The "next" branch(es) being one step away by default.
2058 Options:
2059 -i show dependencies based on index instead of branch
2060 -w show dependencies based on working tree instead of branch
2061 -n <steps> take ``<steps>`` "next" steps (default 1)
2062 --all take as many "next" steps as possible (aka ``-a``)
2063 --verbose show containing series name(s) (aka ``-v``)
2065 The ``-n`` option may also be given as ``--count`` or ``--count=<n>``.
2067 To list all dependents of a branch see the ``--dependents`` option of
2068 the `tg info`_ command.
2070 See also NAVIGATION_ for full details on "next" steps.
2072 tg migrate-bases
2073 ~~~~~~~~~~~~~~~~
2074 Transition top-bases from old location to new location.
2076 Beginning with TopGit release 0.19.4, TopGit has the ability to store
2077 the top-bases refs in either the old ``ref/top-bases/...`` location or
2078 the new ``refs/heads/{top-bases}/...`` location. Starting with TopGit
2079 release 0.20.0, the default is the new location.
2081 By storing the top-bases under heads, Git is less likely to complain
2082 when manipulating them, hosting providers are more likely to provide
2083 access to them and Git prevents them from pointing at anything other
2084 than a commit object. All in all a win for everyone.
2086 TopGit attempts to automatically detect whether the new or old location
2087 is being used for the top-bases and just do the right thing. However,
2088 by explicitly setting the config value ``topgit.top-bases`` to either
2089 ``refs`` for the old location or ``heads`` for the new location the
2090 auto-detection can be bypassed. If no top-bases refs are present in
2091 the repository the default prior to TopGit release 0.20.0 is to use the
2092 old location but starting with TopGit release 0.20.0 the default is to
2093 use the new location.
2095 The ``tg migrate-bases`` command may be used to migrate top-bases refs
2096 from the old location to the new location (or, by using the
2097 undocumented ``--reverse`` option, vice versa).
2099 With few exceptions (``tg create -r`` and ``tg revert``), all top-bases
2100 refs (both local *and* remote refs) are expected to be stored in the
2101 same location (either new or old). A repository's current location for
2102 storing top-bases refs may be shown with the ``tg --top-bases`` command.
2104 TODO: tg rename
2105 ~~~~~~~~~~~~~~~
2107 IMPLEMENTATION
2108 --------------
2110 TopGit stores all the topic branches in the regular ``refs/heads/``
2111 namespace (so we recommend distinguishing them with the ``t/`` prefix).
2112 Apart from that, TopGit also maintains a set of auxiliary refs in
2113 ``refs/top-*``. Currently, only ``refs/top-bases/`` is used, containing the
2114 current *base* of the given topic branch -- this is basically a merge of
2115 all the branches the topic branch depends on; it is updated during ``tg
2116 update`` and then merged to the topic branch, and it is the base of a
2117 patch generated from the topic branch by ``tg patch``.
2119 All the metadata is tracked within the source tree and history of the
2120 topic branch itself, in ``.top*`` files; these files are kept isolated
2121 within the topic branches during TopGit-controlled merges and are of
2122 course omitted during ``tg patch``. The state of these files in base
2123 commits is undefined; look at them only in the topic branches
2124 themselves. Currently, two files are defined:
2126 ``.topmsg``:
2127 Contains the description of the topic branch in a
2128 mail-like format, plus the author information, whatever
2129 Cc headers you choose or the post-three-dashes message.
2130 When mailing out your patch, basically only a few extra
2131 mail headers are inserted and then the patch itself is
2132 appended. Thus, as your patches evolve, you can record
2133 nuances like whether the particular patch should have
2134 To-list / Cc-maintainer or vice-versa and similar
2135 nuances, if your project is into that. ``From`` is
2136 prefilled from your current ``GIT_AUTHOR_IDENT``; other
2137 headers can be prefilled from various optional
2138 ``topgit.*`` git config options.
2140 ``.topdeps``:
2141 Contains the one-per-line list of branches this branch
2142 depends on, pre-seeded by ``tg create``. A (continuously
2143 updated) merge of these branches will be the *base* of
2144 your topic branch.
2146 IMPORTANT: DO NOT EDIT ``.topdeps`` MANUALLY!!! If you do so, you need to
2147 know exactly what you are doing, since this file must stay in sync with
2148 the Git history information, otherwise very bad things will happen.
2150 TopGit also automagically installs a bunch of custom commit-related
2151 hooks that will verify whether you are committing the ``.top*`` files in a
2152 sane state. It will add the hooks to separate files within the ``hooks/``
2153 subdirectory, and merely insert calls to them to the appropriate hooks
2154 and make them executable (but will make sure the original hook's code is
2155 not called if the hook was not executable beforehand).
2157 Another automagically installed piece is a ``.git/info/attributes``
2158 specifier for an ``ours`` merge strategy for the files ``.topmsg`` and
2159 ``.topdeps``, and the (intuitive) ``ours`` merge strategy definition in
2160 ``.git/config``.
2163 REMOTE HANDLING
2164 ---------------
2166 There are two remaining issues with accessing topic branches in remote
2167 repositories:
2169 (i) Referring to remote topic branches from your local repository
2170 (ii) Developing some of the remote topic branches locally
2172 There are two somewhat contradictory design considerations here:
2174 (a) Hacking on multiple independent TopGit remotes in a single
2175 repository
2176 (b) Having a self-contained topic system in local refs space
2178 To us, (a) does not appear to be very convincing, while (b) is quite
2179 desirable for ``git-log topic`` etc. working, and increased conceptual
2180 simplicity.
2182 Thus, we choose to instantiate all the topic branches of given remote
2183 locally; this is performed by ``tg remote --populate``. ``tg update``
2184 will also check if a branch can be updated from its corresponding remote
2185 branch. The logic needs to be somewhat involved if we are to "do the
2186 right thing". First, we update the base, handling the remote branch as
2187 if it was the first dependency; thus, conflict resolutions made in the
2188 remote branch will be carried over to our local base automagically.
2189 Then, the base is merged into the remote branch and the result is merged
2190 to the local branch -- again, to carry over remote conflict resolutions.
2191 In the future, this order might be adjustable on a per-update basis, in
2192 case local changes happen to be diverging more than the remote ones.
2193 (See the details in `The Update Process`_ for more in depth coverage.)
2195 All commands by default refer to the remote that ``tg remote --populate``
2196 was called on the last time (stored in the ``topgit.remote`` git
2197 configuration variable). You can manually run any command with a
2198 different base remote by passing ``-r REMOTE`` *before* the subcommand
2199 name or passing ``-u`` *before* the subcommand to run without one.
2202 TESTING TOPGIT
2203 --------------
2205 Running the TopGit test suite only requires POSIX compatibile utilities (just
2206 a POSIX compatibile ``make`` will do) AND a ``perl`` binary.
2208 It is *not* necessary to install TopGit in order to run the TopGit test suite.
2210 To run the TopGit test suite, simply execute this from the top-level of a
2211 TopGit checkout or expanded release tarball:
2213 ::
2215 make test
2217 Yup, that's it. But you're probably thinking, "Why have a whole section just
2218 to say 'run make test'?" Am I right?
2220 The simple ``make test`` command produces a lot of output and while it is
2221 summarized at the end there's a better way.
2223 Do you have the ``prove`` utility available? You need ``perl`` to run the
2224 tests and ``prove`` comes with ``perl`` so you almost cerainly do.
2226 Try running the tests like so:
2228 ::
2230 make DEFAULT_TEST_TARGET=prove test
2233 (For reference, the default value of ``DEFAULT_TEST_TARGET`` is ``test`` which
2234 can be used to override a setting that's been altered using the instructions
2235 shown later on below.)
2237 If that works (you can interrupt it with ``Ctrl-C``), try this next:
2239 ::
2241 make DEFAULT_TEST_TARGET=prove TESTLIB_PROVE_OPTS="-j 4 --timer" test
2243 If that one works (again, you can interrupt it with ``Ctrl-C``) that may end
2244 up being the keeper for running the tests.
2246 However, if you don't have ``prove`` for some reason even though you do have
2247 ``perl``, there's still an alternative for briefer output. Try this:
2249 ::
2251 make TESTLIB_TEST_OPTS=-q test
2253 Much of the normal testing output will be suppressed and there's still a
2254 summary at the end. If you're stuck with this version but your make supports
2255 parallel operation (the ``-j`` *<n>*) option, then you might try this:
2257 ::
2259 make -j 4 TESTLIB_TEST_OPTS=-q test
2261 If your make *does* support the parallel ``-j`` option but still seems to be
2262 only running one test at a time try it like this instead:
2264 ::
2266 make TESTLIB_MAKE_OPTS="-j 4" TESTLIB_TEST_OPTS=-q test
2268 The difference is that ``make -j 4`` relies on make to properly pass down the
2269 parallel job option all the way down to the sub-make that runs the individual
2270 tests when not using prove. Putting the options in ``TESTLIB_MAKE_OPTS``
2271 passes them directly to that (and only that) particular invocation of make.
2273 The final bit of advice for running the tests is that any of those ``make``
2274 variable settings can be enabled by default in a top-level ``config.mak`` file.
2276 For example, to make the ``prove -j 4 --timer`` (my personal favorite) the
2277 default when running the tests, add these lines (creating the file if it does
2278 not already exist) to the ``config.mak`` file located in the top-level of the
2279 TopGit checkout (or expanded release tarball):
2281 ::
2283 # config.mak file
2284 # comments are allowed (if preceded by '#')
2285 # so are blank lines
2287 DEFAULT_TEST_TARGET = prove
2288 TESTLIB_PROVE_OPTS = -j 4 --timer
2289 #TESTLIB_TEST_OPTS = --color # force colorized test output
2291 Now simply doing ``make test`` will use those options by default.
2293 There is copious documentation on the testing library and other options in
2294 the various ``README`` files located in the ``t`` subdirectory. The
2295 ``Makefile.mak`` file in the ``t`` subdirectory contains plenty of comments
2296 about possible makefile variable settings as well.
2300 TECHNICAL
2301 ---------
2303 A familiarity with the terms in the GLOSSARY_ is helpful for understanding the
2304 content of this sections. See also the IMPLEMENTATION_ section.
2306 The Update Process
2307 ~~~~~~~~~~~~~~~~~~
2309 When a branch is "updated" using the ``tg update`` command the following steps
2310 are taken:
2312 1) The branch and all of its dependencies (and theirs recursively)
2313 are checked to see which ones are *out-of-date*. See glossary_.
2315 2) Each of the branch's direct dependencies (i.e. they are listed in
2316 the branch's ``.topdeps`` file) which is out of date is updated
2317 before proceeding (yup, this is a recursive process).
2319 3) Each of the branch's direct dependencies (i.e. they are listed in
2320 the branch's ``.topdes`` file) that was updated in the previous
2321 step is now merged into the branch's corresponding base. If a
2322 remote is involved, and the branch's corresponding base does NOT
2323 contain the remote branch's corresponding base that remote base is
2324 also merged into the branch's base at this time as well (it will be
2325 the first item merged into the branch's base).
2327 4) If the branch has a corresponding remote branch and the branch
2328 does not already contain it, it's merged into the branch's base
2329 (which was possibly already updated in step (3) to contain the
2330 remote branch's base but not the remote branch itself) on a detached
2331 HEAD. Yup, this step can be a bit confusing and no, the updated
2332 base from step (3) has not yet been merged into the branch itself
2333 yet either. If there is no remote branch this step does not apply.
2334 Using a detached HEAD allows the remote branch to be merged into the
2335 contents of the base without actually perturbing the base's ref.
2337 5) If there is a remote branch present then use the result of step (4)
2338 otherwise use the branch's base and merge that into the branch
2339 itself.
2341 That's it! Simple, right? ;)
2343 Unless the auto stash option has been disabled (see `no undo`_, `tg update`_
2344 and `tg tag`_), a copy of all the old refs values will be stashed away
2345 immediately after step (1) before starting step (2), but only if anything is
2346 actually found to be out-of-date.
2348 Merge Strategies
2349 ~~~~~~~~~~~~~~~~
2351 The ``tg update`` command regularly performs merges while executing an update
2352 operation. In order to speed things up, it attempts to do in-index merges
2353 where possible. It accomplishes this by using a separate, temporary index
2354 file and the ``git read-tree -m --aggressive`` command possibly assisted by
2355 the ``git merge-index`` and ``git merge-file`` commands. This combination may
2356 be repeated more than once to perform an octopus in-index merge. If this
2357 fails, the files are checked out and a normal ``git merge`` three-way merge is
2358 performed (possily multiple times). If the normal ``git merge`` fails then
2359 user intervention is required to resolve the merge conflict(s) and continue.
2361 Since the ``tg annihilate``, ``tg create`` and ``tg depend add`` commands may
2362 end up running the ``tg update`` machinery behind the scenes to complete their
2363 operation they may also result in any of these merge strategies being used.
2365 In addition to the normal Git merge strategies (if the in-index merging fails),
2366 there are four possible TopGit merge strategies that may be shown. Since they
2367 all involve use of the ``git read-tree -m --aggressive`` command they are all
2368 variations of a "trivial aggressive" merge. The "trivial" part because all of
2369 the merges done by ``git read-tree -m`` are described as "trivial" and the
2370 "aggressive" part because the ``--aggressive`` option is always used.
2372 1) "trivial aggressive"
2373 Only two heads were involved and all merging was completed by
2374 the ``git read-tree -m --aggressive`` command.
2376 2) "trivial aggressive automatic"
2377 Only two heads were involved but after the
2378 ``git read-tree -m --aggressive`` command completed there were
2379 still unresolved items and ``git merge-index`` had to be run
2380 (using the ``tg index-merge-one-file`` driver) which ultimately
2381 ran ``git merge-file`` at least once to perform a simple
2382 automatic three-way merge. Hence the "automatic" description
2383 and the "Auto-merging ..." output line(s).
2385 3) "trivial aggressive octopus"
2386 This is the same as a "trivial aggressive" merge except that
2387 more than two heads were involved and after merging the first
2388 two heads, the ``git read-tree -m --aggressive`` step was
2389 repeated again on the result for each additional head. All
2390 merging was completed via multiple
2391 ``git read-tree -m --aggressive`` commands only.
2392 This beast is relatively rare in the wild.
2394 4) "trivial aggressive automatic octopus"
2395 This is very similar to the "trivial aggressive octopus"
2396 except that at least one of the ``git read-tree -m --aggressive``
2397 commands left unresolved items that were handled the same way
2398 as the "trivial aggressive automatic" strategy. This species
2399 is commonly seen in the wild.
2402 GLOSSARY
2403 --------
2405 .topmsg
2406 Version-controlled file stored at the root level of each
2407 TopGit branch that contains the patch header for a TopGit
2408 branch. See also IMPLEMENTATION_;
2410 .topdeps
2411 Version-controlled file stored at the root level of each
2412 TopGit branch that lists the branch's dependencies one per
2413 line omitting the leading ``refs/heads/`` part. See also
2414 IMPLEMENTATION_;
2416 branch containment
2417 Given two Git commit identifiers (e.g. hashes) C1 and C2,
2418 commit C1 "contains" commit C2 if either they are the same
2419 commit or C2 can be reached from C1 by following one or more
2420 parent links from C1 (perhaps via one or more intermediate
2421 commits along the way). In other words, if C1 contains C2
2422 then C2 is an ancestor of C1 or conversely C1 is a descendant
2423 of C2. Since a TopGit branch name is also the name of a Git
2424 branch (something located under the ``refs/heads`` Git
2425 namespace) and similarly for a TopGit base, they can both be
2426 resolved to a Git commit identifier and then participate in
2427 a branch containment test. An easy mnemonic for this is
2428 "children contain the genes of their parents."
2430 BRE pattern
2431 A Basic Regular Expression (BRE) pattern. These are older
2432 style regular expressions but have the advantage that all
2433 characters other than ``\``, ``.``, ``*`` and ``[``
2434 automatically match themselves without need for backslash
2435 quoting (well actually, ``^`` and ``$`` are special at the
2436 beginning and end respectively but otherwise match themselves).
2438 contains
2439 See branch containment.
2441 ERE pattern
2442 An Extended Regular Expression (ERE) pattern. These are newer
2443 style regular expressions where all the regular expression
2444 "operator" characters "operate" when NOT preceded by a
2445 backslash and are turned into normal characters with a ``\``.
2446 The backreference atom, however, may not work, but ``?``, ``+``
2447 and ``|`` "operators" do; unlike BREs.
2449 TopGit
2450 Excellent system for managing a history of changes to one
2451 or more possibly interrelated patches.
2453 TopGit branch
2454 A Git branch that has an associated TopGit base. Conceptually
2455 it represents a single patch that is the difference between
2456 the associated TopGit base and the TopGit branch. In other
2457 words ``git diff-tree <TopGit base> <TopGit branch>`` except
2458 that any ``.topdeps`` and/or ``.topmsg`` files are excluded
2459 from the result and the contents of the ``.topmsg`` file from
2460 the TopGit branch is prefixed to the result.
2462 TopGit bare branch
2463 A Git branch whose tree does NOT contain any `.topdeps` or
2464 `.topmsg` entries at the top-level of the tree. It *does*
2465 always have an associated "TopGit base" ref (otherwise it would
2466 not be a "TopGit" branch). See also `BARE BRANCHES`_.
2468 bare branch
2469 In TopGit context, "bare branch" almost always refers to a
2470 "TopGit bare branch" and should be understood to mean such even
2471 if the leading "TopGit" has been left off.
2473 TopGit base
2474 A Git branch that records the base upon which a TopGit branch's
2475 single conceptual "patch" is built. The name of the Git branch
2476 is derived from the TopGit branch name by stripping off the
2477 leading ``refs/heads/`` and appending the correct prefix where
2478 all TopGit bases are stored (typically either
2479 ``refs/top-bases/`` or ``refs/heads/{top-bases}/`` -- the
2480 prefix for any given repository can be shown by using the
2481 ``tg --top-bases`` command and updated using the
2482 ``tg migrate-bases`` command).
2484 All of a TopGit branch's dependencies are merged into the
2485 corresponding TopGit base during a ``tg update`` of a branch.
2487 base
2488 See TopGit base.
2490 TopGit ``[PATCH]`` branch
2491 A TopGit branch whose subject starts with ``[PATCH]``. By
2492 convention these TopGit branches contain a single patch
2493 (equivalent to a single patch file) and have at least one
2494 dependency (i.e. their ``.topdeps`` files are never empty).
2496 TopGit ``[BASE]`` branch
2497 A TopGit branch whose subject starts with ``[BASE]``. By
2498 convention these TopGit branches do not actually contain
2499 any changes and their ``.topdeps`` files are empty. They
2500 are used to control a base dependency that another set of
2501 branches depends on.
2503 TopGit ``[STAGE]`` branch
2504 A TopGit branch whose subject starts with ``[STAGE]``. By
2505 convention these TopGit branches do not actually contain any
2506 changes of their own but do have one or (typically) more
2507 dependencies in their ``.topdeps`` file. These branches are
2508 used to bring together one or (typically) more independent
2509 TopGit ``[PATCH]`` branches into a single branch so that
2510 testing and/or evaluation can be performed on the result.
2512 merge conflict
2513 When merging two (or more) heads that touch the same lines in
2514 the file but in different ways the result is a merge conflict
2515 that requires manual intervention. If a merge conflict occurs
2516 with more than two heads (an octopus merge) it's generally
2517 replaced by multiple three-way merges so that by the time a
2518 user sees a merge conflict needing manual resolution, there
2519 will be only two heads involved.
2521 merge strategy
2522 A Git merge strategy (see the "MERGE STRATEGIES" section of
2523 ``git help merge``) or one of the TopGit `merge strategies`_
2524 used to merge two or more heads.
2526 TopGit merge strategy
2527 See the `Merge Strategies`_ section above for details but
2528 basically these are just in-index merges done using the
2529 ``git read-tree -m --aggressive`` command one or more times
2530 possibily assisted by the ``git merge-index`` and the
2531 ``git merge-file`` commands.
2533 next branch
2534 In TopGit context the "next" branch refers to the branch that
2535 corresponds to the next (aka following) patch in an ordered
2536 (aka linearized) list of patches created by exporting the
2537 TopGit branches in patch application order.
2539 octopus merge
2540 A merge involving more than two heads. Note that if there are
2541 less than three independent heads the resulting merge that
2542 started out as an octopus will end up not actually being an
2543 octopus after all.
2545 out-of-date branch
2546 A TopGit branch is considered to be "out-of-date" when ANY of
2547 the following are true:
2549 a) The TopGit branch does NOT contain its
2550 corresponding base.
2552 b) The TopGit branch does NOT contain its
2553 corresponding remote branch (there may not be
2554 a remote branch in which case this does not apply)
2556 c) The TopGit branch's base does NOT contain its
2557 corresponding remote branch's base (there may not be
2558 a remote branch in which case this does not apply)
2560 d) Any of the TopGit branches listed in the branch's
2561 ``.topdeps`` file are NOT contained by the branch.
2562 (See "branch containment" above.)
2564 e) Any of the TopGit branches listed in the branch's
2565 ``.topdeps`` file are out-of-date.
2567 Note that if a remote branch is present and is NOT out-of-date
2568 then it will contain its own base and (c) is mostly redundant.
2570 previous branch
2571 In TopGit context the "previous" (or "prev") branch refers to
2572 the branch that corresponds to the previous (aka preceding)
2573 patch in an ordered (aka linearized) list of patches created by
2574 exporting the TopGit branches in patch application order.
2576 remote TopGit branch
2577 A Git branch with the same branch name as a TopGit branch
2578 but living under ``refs/remotes/<some remote>/`` instead
2579 of just ``refs/heads/``.
2581 remote TopGit base
2582 The TopGit base branch corresponding to a remote TopGit branch,
2583 which lives under ``refs/remotes/`` somewhere (depending on
2584 what the output of ``tg --top-bases`` is for that remote).
2586 three-way merge
2587 A three-way merge takes a common base and two heads (call them
2588 A and B) and creates a new file that is the common base plus
2589 all of the changes made between the common base and head A
2590 *AND* all of the changes made between the common base and
2591 head B. The technique used to accomplish this is called a
2592 "merge strategy".
2595 REFERENCES
2596 ----------
2598 The following references are useful to understand the development of
2599 topgit and its subcommands.
2601 * tg depend:
2602 http://public-inbox.org/git/36ca99e90904091034m4d4d31dct78acb333612e678@mail.gmail.com/T/#u
2605 THIRD-PARTY SOFTWARE
2606 --------------------
2608 The following software understands TopGit branches:
2610 * `magit <http://magit.github.io/>`_ -- a git mode for emacs
2612 IMPORTANT: Magit requires its topgit mode to be enabled first, as
2613 described in its documentation, in the "Activating extensions"
2614 subsection. If this is not done, it will not push TopGit branches
2615 correctly, so it's important to enable it even if you plan to mostly use
2616 TopGit from the command line.