This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Before 96a8704c makedepend.SH used shell quote syntax that modern
[perl5.git] / pod / perlrepository.pod
CommitLineData
0549aefb
LB
1=for comment
2Consistent formatting of this file is achieved with:
3 perl ./Porting/podtidy pod/perlrepository.pod
4
d7dd28b6
LB
5=head1 NAME
6
7perlrepository - Using the Perl source repository
8
9=head1 SYNOPSIS
10
dc3c3040 11All of Perl's source code is kept centrally in a Git repository at
c26da522
LB
12I<perl5.git.perl.org>. The repository contains many Perl revisions from
13Perl 1 onwards and all the revisions from Perforce, the version control
14system we were using previously. This repository is accessible in
15different ways.
d7dd28b6
LB
16
17The full repository takes up about 80MB of disk space. A check out of
7f4ffa9d 18the blead branch (that is, the main development branch, which contains
6a7cbfe8
LB
19bleadperl, the development version of perl 5) takes up about 160MB of
20disk space (including the repository). A build of bleadperl takes up
21about 200MB (including the repository and the check out).
d7dd28b6
LB
22
23=head1 GETTING ACCESS TO THE REPOSITORY
24
25=head2 READ ACCESS VIA THE WEB
26
dc3c3040
GA
27You may access the repository over the web. This allows you to browse
28the tree, see recent commits, subscribe to RSS feeds for the changes,
29search for particular commits and more. You may access it at:
d7dd28b6
LB
30
31 http://perl5.git.perl.org/perl.git
32
dc3c3040
GA
33A mirror of the repository is found at:
34
35 http://github.com/github/perl
36
d7dd28b6
LB
37=head2 READ ACCESS VIA GIT
38
39You will need a copy of Git for your computer. You can fetch a copy of
40the repository using the Git protocol (which uses port 9418):
41
e0b2b458 42 % git clone git://perl5.git.perl.org/perl.git perl-git
d7dd28b6 43
f755e97d 44This clones the repository and makes a local copy in the F<perl-git>
d7dd28b6
LB
45directory.
46
47If your local network does not allow you to use port 9418, then you can
cf5e7595 48fetch a copy of the repository over HTTP (this is at least 4x slower):
d7dd28b6 49
e0b2b458 50 % git clone http://perl5.git.perl.org/perl.git perl-http
d7dd28b6 51
f755e97d 52This clones the repository and makes a local copy in the F<perl-http>
d7dd28b6
LB
53directory.
54
55=head2 WRITE ACCESS TO THE REPOSITORY
56
6acba58e
LB
57If you are a committer, then you can fetch a copy of the repository
58that you can push back on with:
d7dd28b6 59
e0b2b458 60 % git clone ssh://perl5.git.perl.org/perl.git perl-ssh
d7dd28b6 61
8f718e95 62This clones the repository and makes a local copy in the F<perl-ssh>
d7dd28b6
LB
63directory.
64
c26da522 65If you cloned using the git protocol, which is faster than ssh, then
11ed6e28
AB
66you will need to modify the URL for the origin remote to enable
67pushing. To do that edit F<.git/config> with L<git-config(1)> like
68this:
1a0f15d5 69
e0b2b458 70 % git config remote.origin.url ssh://perl5.git.perl.org/perl.git
d7dd28b6 71
9d77ce3f
AB
72You can also set up your user name and e-mail address. Most people do
73this once globally in their F<~/.gitconfig> by doing something like:
184487f0 74
9d77ce3f
AB
75 % git config --global user.name "Ævar Arnfjörð Bjarmason"
76 % git config --global user.email avarab@gmail.com
77
78However if you'd like to override that just for perl then execute then
79execute something like the following in F<perl-git>:
80
81 % git config user.email avar@cpan.org
184487f0 82
6acba58e
LB
83It is also possible to keep C<origin> as a git remote, and add a new
84remote for ssh access:
f6c12373 85
dc3c3040 86 % git remote add camel perl5.git.perl.org:/perl.git
f6c12373 87
6acba58e 88This allows you to update your local repository by pulling from
f755e97d 89C<origin>, which is faster and doesn't require you to authenticate, and
6acba58e 90to push your changes back with the C<camel> remote:
f6c12373
VP
91
92 % git fetch camel
93 % git push camel
94
6acba58e
LB
95The C<fetch> command just updates the C<camel> refs, as the objects
96themselves should have been fetched when pulling from C<origin>.
f6c12373 97
3482f01a
DK
98=head2 A NOTE ON CAMEL AND DROMEDARY
99
100The committers have SSH access to the two servers that serve
333f8875
VP
101C<perl5.git.perl.org>. One is C<perl5.git.perl.org> itself (I<camel>),
102which is the 'master' repository. The second one is
103C<users.perl5.git.perl.org> (I<dromedary>), which can be used for
104general testing and development. Dromedary syncs the git tree from
105camel every few minutes, you should not push there. Both machines also
3482f01a
DK
106have a full CPAN mirror in /srv/CPAN, please use this. To share files
107with the general public, dromedary serves your ~/public_html/ as
333f8875 108C<http://users.perl5.git.perl.org/~yourlogin/>
b47aa495 109
3482f01a
DK
110These hosts have fairly strict firewalls to the outside. Outgoing, only
111rsync, ssh and git are allowed. For http and ftp, you can use
112http://webproxy:3128 as proxy. Incoming, the firewall tries to detect
113attacks and blocks IP addresses with suspicious activity. This
114sometimes (but very rarely) has false positives and you might get
115blocked. The quickest way to get unblocked is to notify the admins.
116
117These two boxes are owned, hosted, and operated by booking.com. You can
118reach the sysadmins in #p5p on irc.perl.org or via mail to
119C<perl5-porters@perl.org>
120
d7dd28b6
LB
121=head1 OVERVIEW OF THE REPOSITORY
122
6acba58e
LB
123Once you have changed into the repository directory, you can inspect
124it.
d7dd28b6 125
39219fd3 126After a clone the repository will contain a single local branch, which
50eca761 127will be the current branch as well, as indicated by the asterisk.
39219fd3
YO
128
129 % git branch
130 * blead
131
f755e97d 132Using the -a switch to C<branch> will also show the remote tracking
6acba58e 133branches in the repository:
39219fd3 134
d9847473 135 % git branch -a
09081495 136 * blead
d7dd28b6
LB
137 origin/HEAD
138 origin/blead
139 ...
140
6acba58e
LB
141The branches that begin with "origin" correspond to the "git remote"
142that you cloned from (which is named "origin"). Each branch on the
143remote will be exactly tracked by theses branches. You should NEVER do
144work on these remote tracking branches. You only ever do work in a
145local branch. Local branches can be configured to automerge (on pull)
146from a designated remote tracking branch. This is the case with the
147default branch C<blead> which will be configured to merge from the
148remote tracking branch C<origin/blead>.
39219fd3 149
d7dd28b6
LB
150You can see recent commits:
151
c2cf2042 152 % git log
d7dd28b6 153
6acba58e
LB
154And pull new changes from the repository, and update your local
155repository (must be clean first)
d7dd28b6
LB
156
157 % git pull
09081495 158
6acba58e
LB
159Assuming we are on the branch C<blead> immediately after a pull, this
160command would be more or less equivalent to:
39219fd3
YO
161
162 % git fetch
163 % git merge origin/blead
164
6acba58e
LB
165In fact if you want to update your local repository without touching
166your working directory you do:
39219fd3
YO
167
168 % git fetch
169
6acba58e
LB
170And if you want to update your remote-tracking branches for all defined
171remotes simultaneously you can do
39219fd3
YO
172
173 % git remote update
174
6acba58e
LB
175Neither of these last two commands will update your working directory,
176however both will update the remote-tracking branches in your
177repository.
39219fd3 178
09081495
LB
179To switch to another branch:
180
181 % git checkout origin/maint-5.8-dor
182
6051489b
NC
183To make a local branch of a remote branch:
184
185 % git checkout -b maint-5.10 origin/maint-5.10
186
09081495
LB
187To switch back to blead:
188
189 % git checkout blead
c2cf2042 190
39219fd3
YO
191=head2 FINDING OUT YOUR STATUS
192
193The most common git command you will use will probably be
194
195 % git status
196
6acba58e
LB
197This command will produce as output a description of the current state
198of the repository, including modified files and unignored untracked
199files, and in addition it will show things like what files have been
200staged for the next commit, and usually some useful information about
201how to change things. For instance the following:
39219fd3
YO
202
203 $ git status
204 # On branch blead
205 # Your branch is ahead of 'origin/blead' by 1 commit.
206 #
207 # Changes to be committed:
208 # (use "git reset HEAD <file>..." to unstage)
209 #
210 # modified: pod/perlrepository.pod
211 #
212 # Changed but not updated:
213 # (use "git add <file>..." to update what will be committed)
214 #
215 # modified: pod/perlrepository.pod
216 #
217 # Untracked files:
218 # (use "git add <file>..." to include in what will be committed)
219 #
220 # deliberate.untracked
221
6acba58e
LB
222This shows that there were changes to this document staged for commit,
223and that there were further changes in the working directory not yet
224staged. It also shows that there was an untracked file in the working
225directory, and as you can see shows how to change all of this. It also
0549aefb
LB
226shows that there is one commit on the working branch C<blead> which has
227not been pushed to the C<origin> remote yet. B<NOTE>: that this output
228is also what you see as a template if you do not provide a message to
229C<git commit>.
7f6effc7 230
bdaf0bc6
JV
231Assuming that you'd like to commit all the changes you've just made as a
232a single atomic unit, run this command:
233
234 % git commit -a
235
236(That C<-a> tells git to add every file you've changed to this commit.
ea9c0d74
JV
237New files aren't automatically added to your commit when you use C<commit
238-a> If you want to add files or to commit some, but not all of your
239changes, have a look at the documentation for C<git add>.)
bdaf0bc6 240
e9360695 241Git will start up your favorite text editor, so that you can craft a
bdaf0bc6
JV
242commit message for your change. See L</Commit message> below for more
243information about what makes a good commit message.
244
245Once you've finished writing your commit message and exited your editor,
246git will write your change to disk and tell you something like this:
7f6effc7 247
7f6effc7
YO
248 Created commit daf8e63: explain git status and stuff about remotes
249 1 files changed, 83 insertions(+), 3 deletions(-)
250
bdaf0bc6
JV
251
252If you re-run C<git status>, you should see something like this:
7f6effc7
YO
253
254 % git status
255 # On branch blead
256 # Your branch is ahead of 'origin/blead' by 2 commits.
257 #
258 # Untracked files:
259 # (use "git add <file>..." to include in what will be committed)
260 #
261 # deliberate.untracked
262 nothing added to commit but untracked files present (use "git add" to track)
263
39219fd3 264
6acba58e
LB
265When in doubt, before you do anything else, check your status and read
266it carefully, many questions are answered directly by the git status
267output.
39219fd3 268
c2cf2042
LB
269=head1 SUBMITTING A PATCH
270
271If you have a patch in mind for Perl, you should first get a copy of
272the repository:
273
274 % git clone git://perl5.git.perl.org/perl.git perl-git
275
276Then change into the directory:
277
278 % cd perl-git
279
6acba58e
LB
280Alternatively, if you already have a Perl repository, you should ensure
281that you're on the I<blead> branch, and your repository is up to date:
12322d22
A
282
283 % git checkout blead
284 % git pull
285
6a7cbfe8
LB
286It's preferable to patch against the latest blead version, since this
287is where new development occurs for all changes other than critical bug
288fixes. Critical bug fix patches should be made against the relevant
7f4ffa9d
RS
289maint branches, or should be submitted with a note indicating all the
290branches where the fix should be applied.
a44f43ac 291
6acba58e
LB
292Now that we have everything up to date, we need to create a temporary
293new branch for these changes and switch into it:
b1fccde5 294
a9b05323 295 % git checkout -b orange
23f8d33e 296
a9b05323
YO
297which is the short form of
298
b1fccde5
LB
299 % git branch orange
300 % git checkout orange
301
0c24b290
AB
302Creating a topic branch makes it easier for the maintainers to rebase
303or merge back into the master blead for a more linear history. If you
304don't work on a topic branch the maintainer has to manually cherry
305pick your changes onto blead before they can be applied.
306
307That'll get you scolded on perl5-porters, so don't do that. Be
308Awesome.
309
c2cf2042
LB
310Then make your changes. For example, if Leon Brocard changes his name
311to Orange Brocard, we should change his name in the AUTHORS file:
312
313 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
314
315You can see what files are changed:
316
317 % git status
f755e97d 318 # On branch orange
c2cf2042
LB
319 # Changes to be committed:
320 # (use "git reset HEAD <file>..." to unstage)
321 #
2699d634 322 # modified: AUTHORS
c2cf2042
LB
323 #
324
c2cf2042
LB
325And you can see the changes:
326
327 % git diff
328 diff --git a/AUTHORS b/AUTHORS
329 index 293dd70..722c93e 100644
330 --- a/AUTHORS
331 +++ b/AUTHORS
7df2e4bc 332 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
c2cf2042
LB
333 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
334 Leif Huhn <leif@hale.dkstat.com>
335 Len Johnson <lenjay@ibm.net>
336 -Leon Brocard <acme@astray.com>
337 +Orange Brocard <acme@astray.com>
338 Les Peters <lpeters@aol.net>
339 Lesley Binks <lesley.binks@gmail.com>
340 Lincoln D. Stein <lstein@cshl.org>
341
342Now commit your change locally:
343
dc3c3040 344 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
c2cf2042
LB
345 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
346 1 files changed, 1 insertions(+), 1 deletions(-)
347
dc3c3040
GA
348You can examine your last commit with:
349
350 % git show HEAD
351
352and if you are not happy with either the description or the patch
c26da522 353itself you can fix it up by editing the files once more and then issue:
dc3c3040
GA
354
355 % git commit -a --amend
356
c2cf2042
LB
357Now you should create a patch file for all your local changes:
358
2af192ee 359 % git format-patch origin
c2cf2042
LB
360 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
361
362You should now send an email to perl5-porters@perl.org with a
dc3c3040 363description of your changes, and include this patch file as an
333f8875
VP
364attachment. (See the next section for how to configure and use git to
365send these emails for you.)
c2cf2042 366
b1fccde5
LB
367If you want to delete your temporary branch, you may do so with:
368
369 % git checkout blead
370 % git branch -d orange
371 error: The branch 'orange' is not an ancestor of your current HEAD.
372 If you are sure you want to delete it, run 'git branch -D orange'.
373 % git branch -D orange
374 Deleted branch orange.
7df2e4bc 375
2d5f1d01
DG
376=head2 Using git to send patch emails
377
333f8875
VP
378In your ~/git/perl repository, set the destination email to the
379perl5-porters mailing list.
2d5f1d01
DG
380
381 $ git config sendemail.to perl5-porters@perl.org
382
383Then you can use git directly to send your patch emails:
384
385 $ git send-email 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
386
333f8875
VP
387You may need to set some configuration variables for your particular
388email service provider. For example, to set your global git config to
389send email via a gmail account:
2d5f1d01
DG
390
391 $ git config --global sendemail.smtpserver smtp.gmail.com
392 $ git config --global sendemail.smtpssl 1
393 $ git config --global sendemail.smtpuser YOURUSERNAME@gmail.com
394
333f8875
VP
395With this configuration, you will be prompted for your gmail password
396when you run 'git send-email'. You can also configure
397C<sendemail.smtppass> with your password if you don't care about having
398your password in the .gitconfig file.
2d5f1d01 399
a44f43ac
RGS
400=head2 A note on derived files
401
402Be aware that many files in the distribution are derivative--avoid
0549aefb
LB
403patching them, because git won't see the changes to them, and the build
404process will overwrite them. Patch the originals instead. Most
405utilities (like perldoc) are in this category, i.e. patch
406utils/perldoc.PL rather than utils/perldoc. Similarly, don't create
407patches for files under $src_root/ext from their copies found in
408$install_root/lib. If you are unsure about the proper location of a
409file that may have gotten copied while building the source
410distribution, consult the C<MANIFEST>.
a44f43ac 411
ac1cbfb0
JC
412As a special case, several files are regenerated by 'make regen' if
413your patch alters C<embed.fnc>. These are needed for compilation, but
414are included in the distribution so that you can build perl without
415needing another perl to generate the files. You must test with these
416regenerated files, but it is preferred that you instead note that
417'make regen is needed' in both the email and the commit message, and
418submit your patch without them. If you're submitting a series of
419patches, it might be best to submit the regenerated changes
420immediately after the source-changes that caused them, so as to have
421as little effect as possible on the bisectability of your patchset.
422
6e2cec71 423=for XXX
a44f43ac 424
6e2cec71 425What should we recommend about binary files now? Do we need anything?
a44f43ac
RGS
426
427=head2 Getting your patch accepted
428
bdaf0bc6 429If you are submitting a code patch there are several things that
a44f43ac
RGS
430you need to do.
431
432=over 4
433
bdaf0bc6
JV
434=item Commit message
435
436As you craft each patch you intend to submit to the Perl core, it's
437important to write a good commit message.
438
439Your commit message should start with a description of the problem that
440the patch corrects or new functionality that the patch adds.
441
bdaf0bc6
JV
442As a general rule of thumb, your commit message should let a programmer
443with a reasonable familiarity with the Perl core quickly understand what
444you were trying to do, how you were trying to do it and why the change
445matters to Perl.
446
447=over 4
448
449=item What
450
ac1cbfb0
JC
451Your commit message should describe what part of the Perl core you're
452changing and what you expect your patch to do.
bdaf0bc6
JV
453
454=item Why
455
456Perhaps most importantly, your commit message should describe why the
457change you are making is important. When someone looks at your change
458in six months or six years, your intent should be clear. If you're
459deprecating a feature with the intent of later simplifying another bit
460of code, say so. If you're fixing a performance problem or adding a new
461feature to support some other bit of the core, mention that.
462
463=item How
464
465While it's not necessary for documentation changes, new tests or
466trivial patches, it's often worth explaining how your change works.
467Even if it's clear to you today, it may not be clear to a porter next
468month or next year.
469
470=back
471
ea9c0d74
JV
472A commit message isn't intended to take the place of comments in your
473code. Commit messages should describe the change you made, while code
80a0006a
JV
474comments should describe the current state of the code. If you've just
475implemented a new feature, complete with doc, tests and well-commented
476code, a brief commit message will often suffice. If, however, you've
477just changed a single character deep in the parser or lexer, you might
ea9c0d74
JV
478need to write a small novel to ensure that future readers understand
479what you did and why you did it.
480
a44f43ac
RGS
481=item Comments, Comments, Comments
482
0549aefb
LB
483Be sure to adequately comment your code. While commenting every line
484is unnecessary, anything that takes advantage of side effects of
a44f43ac 485operators, that creates changes that will be felt outside of the
0549aefb
LB
486function being patched, or that others may find confusing should be
487documented. If you are going to err, it is better to err on the side
488of adding too many comments than too few.
a44f43ac
RGS
489
490=item Style
491
0549aefb
LB
492In general, please follow the particular style of the code you are
493patching.
a44f43ac 494
0549aefb
LB
495In particular, follow these general guidelines for patching Perl
496sources:
a44f43ac
RGS
497
498 8-wide tabs (no exceptions!)
499 4-wide indents for code, 2-wide indents for nested CPP #defines
500 try hard not to exceed 79-columns
501 ANSI C prototypes
502 uncuddled elses and "K&R" style for indenting control constructs
503 no C++ style (//) comments
504 mark places that need to be revisited with XXX (and revisit often!)
505 opening brace lines up with "if" when conditional spans multiple
506 lines; should be at end-of-line otherwise
507 in function definitions, name starts in column 0 (return value is on
508 previous line)
509 single space after keywords that are followed by parens, no space
510 between function name and following paren
511 avoid assignments in conditionals, but if they're unavoidable, use
512 extra paren, e.g. "if (a && (b = c)) ..."
513 "return foo;" rather than "return(foo);"
514 "if (!foo) ..." rather than "if (foo == FALSE) ..." etc.
515
516=item Testsuite
517
bdaf0bc6
JV
518If your patch changes code (rather than just changing documentation) you
519should also include one or more test cases which illustrate the bug you're
520fixing or validate the new functionality you're adding. In general,
521you should update an existing test file rather than create a new one.
522
0549aefb
LB
523Your testsuite additions should generally follow these guidelines
524(courtesy of Gurusamy Sarathy <gsar@activestate.com>):
a44f43ac
RGS
525
526 Know what you're testing. Read the docs, and the source.
527 Tend to fail, not succeed.
528 Interpret results strictly.
529 Use unrelated features (this will flush out bizarre interactions).
530 Use non-standard idioms (otherwise you are not testing TIMTOWTDI).
531 Avoid using hardcoded test numbers whenever possible (the
532 EXPECTED/GOT found in t/op/tie.t is much more maintainable,
533 and gives better failure reports).
534 Give meaningful error messages when a test fails.
535 Avoid using qx// and system() unless you are testing for them. If you
536 do use them, make sure that you cover _all_ perl platforms.
537 Unlink any temporary files you create.
538 Promote unforeseen warnings to errors with $SIG{__WARN__}.
539 Be sure to use the libraries and modules shipped with the version
540 being tested, not those that were already installed.
541 Add comments to the code explaining what you are testing for.
542 Make updating the '1..42' string unnecessary. Or make sure that
543 you update it.
544 Test _all_ behaviors of a given operator, library, or function:
545 - All optional arguments
546 - Return values in various contexts (boolean, scalar, list, lvalue)
547 - Use both global and lexical variables
548 - Don't forget the exceptional, pathological cases.
549
550=back
551
7df2e4bc
LB
552=head1 ACCEPTING A PATCH
553
554If you have received a patch file generated using the above section,
555you should try out the patch.
556
557First we need to create a temporary new branch for these changes and
558switch into it:
559
a9b05323 560 % git checkout -b experimental
7df2e4bc 561
6acba58e
LB
562Patches that were formatted by C<git format-patch> are applied with
563C<git am>:
7df2e4bc 564
2af192ee 565 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
7df2e4bc
LB
566 Applying Rename Leon Brocard to Orange Brocard
567
6acba58e
LB
568If just a raw diff is provided, it is also possible use this two-step
569process:
09645c26
VP
570
571 % git apply bugfix.diff
dc3c3040 572 % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"
09645c26 573
7df2e4bc
LB
574Now we can inspect the change:
575
dc3c3040 576 % git show HEAD
7df2e4bc
LB
577 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
578 Author: Leon Brocard <acme@astray.com>
579 Date: Fri Dec 19 17:02:59 2008 +0000
580
581 Rename Leon Brocard to Orange Brocard
7df2e4bc 582
7df2e4bc
LB
583 diff --git a/AUTHORS b/AUTHORS
584 index 293dd70..722c93e 100644
585 --- a/AUTHORS
586 +++ b/AUTHORS
587 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
588 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
589 Leif Huhn <leif@hale.dkstat.com>
590 Len Johnson <lenjay@ibm.net>
591 -Leon Brocard <acme@astray.com>
592 +Orange Brocard <acme@astray.com>
593 Les Peters <lpeters@aol.net>
594 Lesley Binks <lesley.binks@gmail.com>
595 Lincoln D. Stein <lstein@cshl.org>
596
597If you are a committer to Perl and you think the patch is good, you can
75fb7651 598then merge it into blead then push it out to the main repository:
7df2e4bc
LB
599
600 % git checkout blead
d9847473 601 % git merge experimental
75fb7651 602 % git push
7df2e4bc
LB
603
604If you want to delete your temporary branch, you may do so with:
605
606 % git checkout blead
607 % git branch -d experimental
608 error: The branch 'experimental' is not an ancestor of your current HEAD.
609 If you are sure you want to delete it, run 'git branch -D experimental'.
610 % git branch -D experimental
611 Deleted branch experimental.
b0d36535
YO
612
613=head1 CLEANING A WORKING DIRECTORY
614
6acba58e 615The command C<git clean> can with varying arguments be used as a
dc3c3040 616replacement for C<make clean>.
b0d36535
YO
617
618To reset your working directory to a pristine condition you can do:
619
e0b2b458 620 % git clean -dxf
b0d36535
YO
621
622However, be aware this will delete ALL untracked content. You can use
623
e0b2b458 624 % git clean -Xf
b0d36535 625
6acba58e
LB
626to remove all ignored untracked files, such as build and test
627byproduct, but leave any manually created files alone.
b0d36535 628
0549aefb 629If you only want to cancel some uncommitted edits, you can use C<git
c26da522
LB
630checkout> and give it a list of files to be reverted, or C<git checkout
631-f> to revert them all.
f755e97d
RGS
632
633If you want to cancel one or several commits, you can use C<git reset>.
634
d82a90c1
VP
635=head1 BISECTING
636
6acba58e
LB
637C<git> provides a built-in way to determine, with a binary search in
638the history, which commit should be blamed for introducing a given bug.
d82a90c1 639
6acba58e 640Suppose that we have a script F<~/testcase.pl> that exits with C<0>
bdaf0bc6 641when some behaviour is correct, and with C<1> when it's faulty. You need
6acba58e
LB
642an helper script that automates building C<perl> and running the
643testcase:
d82a90c1
VP
644
645 % cat ~/run
646 #!/bin/sh
647 git clean -dxf
a4583001
AB
648
649 # If you get './makedepend: 1: Syntax error: Unterminated quoted
650 # string' when bisecting versions of perl older than 5.9.5 this hack
651 # will work around the bug in makedepend.SH which was fixed in
652 # version 96a8704c. Make sure to comment out `git co makedepend.SH'
653 # below too.
654 git show blead:makedepend.SH > makedepend.SH
655
d82a90c1 656 # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
1d5fe431
MB
657 # if Encode is not needed for the test, you can speed up the bisect by
658 # excluding it from the runs with -Dnoextensions=Encode
c0d1ef72
MB
659 sh Configure -des -Dusedevel -Doptimize="-g"
660 test -f config.sh || exit 125
661 # Correct makefile for newer GNU gcc
662 perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
663 # if you just need miniperl, replace test_prep with miniperl
d7923bfe 664 make test_prep
68814ba4 665 [ -x ./perl ] || exit 125
d82a90c1 666 ./perl -Ilib ~/testcase.pl
c0d1ef72 667 ret=$?
7930c68b 668 [ $ret -gt 127 ] && ret=127
a4583001 669 # git co makedepend.SH
c0d1ef72
MB
670 git clean -dxf
671 exit $ret
d82a90c1 672
6acba58e
LB
673This script may return C<125> to indicate that the corresponding commit
674should be skipped. Otherwise, it returns the status of
675F<~/testcase.pl>.
d82a90c1 676
bdaf0bc6 677You first enter in bisect mode with:
d82a90c1
VP
678
679 % git bisect start
680
6acba58e
LB
681For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
682C<git> will learn about this when you enter:
d82a90c1
VP
683
684 % git bisect bad
685 % git bisect good perl-5.10.0
686 Bisecting: 853 revisions left to test after this
687
6acba58e 688This results in checking out the median commit between C<HEAD> and
bdaf0bc6 689C<perl-5.10.0>. You can then run the bisecting process with:
d82a90c1
VP
690
691 % git bisect run ~/run
692
693When the first bad commit is isolated, C<git bisect> will tell you so:
694
695 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
696 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
697 Author: Dave Mitchell <davem@fdisolutions.com>
698 Date: Sat Feb 9 14:56:23 2008 +0000
699
9469eb4a 700 [perl #49472] Attributes + Unknown Error
d82a90c1
VP
701 ...
702
703 bisect run success
704
6acba58e
LB
705You can peek into the bisecting process with C<git bisect log> and
706C<git bisect visualize>. C<git bisect reset> will get you out of bisect
707mode.
d82a90c1 708
6acba58e
LB
709Please note that the first C<good> state must be an ancestor of the
710first C<bad> state. If you want to search for the commit that I<solved>
711some bug, you have to negate your test case (i.e. exit with C<1> if OK
712and C<0> if not) and still mark the lower bound as C<good> and the
713upper as C<bad>. The "first bad commit" has then to be understood as
714the "first commit where the bug is solved".
d82a90c1 715
6acba58e
LB
716C<git help bisect> has much more information on how you can tweak your
717binary searches.
9d68b7ed 718
03050721
LB
719=head1 SUBMITTING A PATCH VIA GITHUB
720
721GitHub is a website that makes it easy to fork and publish projects
722with Git. First you should set up a GitHub account and log in.
723
724Perl's git repository is mirrored on GitHub at this page:
725
726 http://github.com/github/perl/tree/blead
727
728Visit the page and click the "fork" button. This clones the Perl git
729repository for you and provides you with "Your Clone URL" from which
730you should clone:
731
732 % git clone git@github.com:USERNAME/perl.git perl-github
733
bdaf0bc6 734The same patch as above, using github might look like this:
03050721
LB
735
736 % cd perl-github
edb9e29e 737 % git remote add upstream git://perl5.git.perl.org/perl.git
03050721
LB
738 % git pull upstream blead
739 % git checkout -b orange
740 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
dc3c3040 741 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
03050721
LB
742 % git push origin orange
743
744The orange branch has been pushed to GitHub, so you should now send an
745email to perl5-porters@perl.org with a description of your changes and
746the following information:
747
748 http://github.com/USERNAME/perl/tree/orange
749 git@github.com:USERNAME/perl.git branch orange
750
c26da522
LB
751=head1 MERGING FROM A BRANCH VIA GITHUB
752
753If someone has provided a branch via GitHub and you are a committer,
5c9c28c6 754you should use the following in your perl-ssh directory:
c26da522
LB
755
756 % git remote add dandv git://github.com/dandv/perl.git
fe442cc0 757 % git fetch dandv
c26da522
LB
758
759Now you can see the differences between the branch and blead:
760
761 % git diff dandv/blead
762
763And you can see the commits:
764
765 % git log dandv/blead
766
767If you approve of a specific commit, you can cherry pick it:
768
2bab0636
LB
769 % git cherry-pick 3adac458cb1c1d41af47fc66e67b49c8dec2323f
770
771Or you could just merge the whole branch if you like it all:
772
773 % git merge dandv/blead
c26da522
LB
774
775And then push back to the repository:
776
777 % git push
778
ce2a8773
JV
779
780=head1 TOPIC BRANCHES AND REWRITING HISTORY
781
782Individual committers should create topic branches under
333f8875
VP
783B<yourname>/B<some_descriptive_name>. Other committers should check
784with a topic branch's creator before making any change to it.
ce2a8773 785
b16add97
AP
786The simplest way to create a remote topic branch that works on all
787versions of git is to push the current head as a new branch on the
788remote, then check it out locally:
789
790 $ branch="$yourname/$some_descriptive_name"
791 $ git push origin HEAD:$branch
792 $ git checkout -b $branch origin/$branch
793
794Users of git 1.7 or newer can do it in a more obvious manner:
795
796 $ branch="$yourname/$some_descriptive_name"
797 $ git checkout -b $branch
798 $ git push origin -u $branch
33e5002f 799
ce2a8773
JV
800If you are not the creator of B<yourname>/B<some_descriptive_name>, you
801might sometimes find that the original author has edited the branch's
802history. There are lots of good reasons for this. Sometimes, an author
333f8875
VP
803might simply be rebasing the branch onto a newer source point.
804Sometimes, an author might have found an error in an early commit which
805they wanted to fix before merging the branch to blead.
ce2a8773 806
333f8875
VP
807Currently the master repository is configured to forbid
808non-fast-forward merges. This means that the branches within can not
809be rebased and pushed as a single step.
ce2a8773 810
333f8875
VP
811The only way you will ever be allowed to rebase or modify the history
812of a pushed branch is to delete it and push it as a new branch under
813the same name. Please think carefully about doing this. It may be
814better to sequentially rename your branches so that it is easier for
815others working with you to cherry-pick their local changes onto the new
816version. (XXX: needs explanation).
ce2a8773
JV
817
818If you want to rebase a personal topic branch, you will have to delete
2699d634
YO
819your existing topic branch and push as a new version of it. You can do
820this via the following formula (see the explanation about C<refspec>'s
821in the git push documentation for details) after you have rebased your
822branch:
823
824 # first rebase
825 $ git checkout $user/$topic
826 $ git fetch
827 $ git rebase origin/blead
828
829 # then "delete-and-push"
830 $ git push origin :$user/$topic
831 $ git push origin $user/$topic
832
833B<NOTE:> it is forbidden at the repository level to delete any of the
333f8875
VP
834"primary" branches. That is any branch matching
835C<m!^(blead|maint|perl)!>. Any attempt to do so will result in git
836producing an error like this:
2699d634
YO
837
838 $ git push origin :blead
839 *** It is forbidden to delete blead/maint branches in this repository
840 error: hooks/update exited with error code 1
841 error: hook declined to update refs/heads/blead
333f8875 842 To ssh://perl5.git.perl.org/perl
2699d634 843 ! [remote rejected] blead (hook declined)
333f8875 844 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl'
2699d634 845
333f8875
VP
846As a matter of policy we do B<not> edit the history of the blead and
847maint-* branches. If a typo (or worse) sneaks into a commit to blead or
848maint-*, we'll fix it in another commit. The only types of updates
849allowed on these branches are "fast-forward's", where all history is
850preserved.
2699d634 851
333f8875
VP
852Annotated tags in the canonical perl.git repository will never be
853deleted or modified. Think long and hard about whether you want to push
854a local tag to perl.git before doing so. (Pushing unannotated tags is
2699d634 855not allowed.)
ce2a8773 856
9469eb4a 857=head1 COMMITTING TO MAINTENANCE VERSIONS
9d68b7ed 858
7f4ffa9d
RS
859Maintenance versions should only be altered to add critical bug fixes.
860
9d68b7ed
LB
861To commit to a maintenance version of perl, you need to create a local
862tracking branch:
863
864 % git checkout --track -b maint-5.005 origin/maint-5.005
865
0549aefb
LB
866This creates a local branch named C<maint-5.005>, which tracks the
867remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
868and push as before.
b0d36535 869
f755e97d 870You can also cherry-pick commits from blead and another branch, by
0549aefb
LB
871using the C<git cherry-pick> command. It is recommended to use the
872B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
873original commit in the new commit message.
f755e97d 874
e8589bfa
AV
875=head1 GRAFTS
876
877The perl history contains one mistake which was not caught in the
ac036724 878conversion: a merge was recorded in the history between blead and
333f8875
VP
879maint-5.10 where no merge actually occurred. Due to the nature of git,
880this is now impossible to fix in the public repository. You can remove
881this mis-merge locally by adding the following line to your
e8589bfa
AV
882C<.git/info/grafts> file:
883
884 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
885
886It is particularly important to have this graft line if any bisecting
887is done in the area of the "merge" in question.
888
bdaf0bc6
JV
889
890
f755e97d
RGS
891=head1 SEE ALSO
892
893The git documentation, accessible via C<git help command>.
0549aefb 894