+=for comment
+Consistent formatting of this file is achieved with:
+ perl ./Porting/podtidy pod/perlrepository.pod
+
=head1 NAME
perlrepository - Using the Perl source repository
=head1 SYNOPSIS
-All of Perl's source code is kept centrally in a Git repository. The
-repository contains many Perl revisions from Perl 1 onwards and all
-the revisions from Perforce, the version control system we were using
-previously. This repository is accessible in different ways.
+All of Perl's source code is kept centrally in a Git repository at
+I<perl5.git.perl.org>. The repository contains many Perl revisions from
+Perl 1 onwards and all the revisions from Perforce, the version control
+system we were using previously. This repository is accessible in
+different ways.
The full repository takes up about 80MB of disk space. A check out of
-blead takes up about 160MB of disk space (including the repository). A
-build of blead takes up about 200MB (including the repository and the
-check out).
+the blead branch (that is, the main development branch, which contains
+bleadperl, the development version of perl 5) takes up about 160MB of
+disk space (including the repository). A build of bleadperl takes up
+about 200MB (including the repository and the check out).
=head1 GETTING ACCESS TO THE REPOSITORY
=head2 READ ACCESS VIA THE WEB
-You may access this over the web. This allows you to browse the tree,
-see recent commits, search for particular commits and more. You may
-access it at:
+You may access the repository over the web. This allows you to browse
+the tree, see recent commits, subscribe to RSS feeds for the changes,
+search for particular commits and more. You may access it at:
http://perl5.git.perl.org/perl.git
+A mirror of the repository is found at:
+
+ http://github.com/github/perl
+
=head2 READ ACCESS VIA GIT
You will need a copy of Git for your computer. You can fetch a copy of
git clone git://perl5.git.perl.org/perl.git perl-git
-This clones the repository and makes a local copy in the 'perl-git'
+This clones the repository and makes a local copy in the F<perl-git>
directory.
If your local network does not allow you to use port 9418, then you can
git clone http://perl5.git.perl.org/perl.git perl-http
-This clones the repository and makes a local copy in the 'perl-http'
+This clones the repository and makes a local copy in the F<perl-http>
directory.
=head2 WRITE ACCESS TO THE REPOSITORY
-If you are a committer, then you can fetch a copy of the repository that
-you can push back on with:
+If you are a committer, then you can fetch a copy of the repository
+that you can push back on with:
git clone ssh://perl5.git.perl.org/gitroot/perl.git perl-ssh
-This clones the repository and makes a local copy in the 'perl-ssh'
+This clones the repository and makes a local copy in the F<perl-ssh>
directory.
-If you clone using git, which is faster than ssh, then you will need to
-modify your config in order to enable pushing. Edit .git/config where
-you will see something like:
+If you cloned using the git protocol, which is faster than ssh, then
+you will need to modify your config in order to enable pushing. Edit
+F<.git/config> where you will see something like:
[remote "origin"]
url = git://perl5.git.perl.org/perl.git
[remote "origin"]
url = ssh://perl5.git.perl.org/gitroot/perl.git
-NOTE: there are symlinks set up so that the /gitroot is actually optional.
+NOTE: there are symlinks set up so that the /gitroot is optional and
+since SSH is the default protocol you can actually shorten the "url" to
+C<perl5.git.perl.org:/perl.git>.
+
+You can also set up your user name and e-mail address. For example
+
+ % git config user.name "Leon Brocard"
+ % git config user.email acme@astray.com
+
+It is also possible to keep C<origin> as a git remote, and add a new
+remote for ssh access:
+
+ % git remote add camel perl5.git.perl.org:/perl.git
+
+This allows you to update your local repository by pulling from
+C<origin>, which is faster and doesn't require you to authenticate, and
+to push your changes back with the C<camel> remote:
+
+ % git fetch camel
+ % git push camel
+
+The C<fetch> command just updates the C<camel> refs, as the objects
+themselves should have been fetched when pulling from C<origin>.
+
+The committers have access to 2 servers that serve perl5.git.perl.org.
+One is camel.booking.com, which is the 'master' repository. The
+perl5.git.perl.org IP address also lives on this machine. The second
+one is dromedary.booking.com, which can be used for general testing and
+development. Dromedary syncs the git tree from camel every few minutes,
+you should not push there. Both machines also have a full CPAN mirror.
+To share files with the general public, dromedary serves your
+~/public_html/ as http://users.perl5.git.perl.org/~yourlogin/
=head1 OVERVIEW OF THE REPOSITORY
-Once you have changed into the repository directory, you can inspect it.
+Once you have changed into the repository directory, you can inspect
+it.
+
+After a clone the repository will contain a single local branch, which
+will be the current branch as well, as indicated by the asterisk.
+
+ % git branch
+ * blead
-The repository contains a few branches:
+Using the -a switch to C<branch> will also show the remote tracking
+branches in the repository:
% git branch -a
* blead
origin/blead
...
+The branches that begin with "origin" correspond to the "git remote"
+that you cloned from (which is named "origin"). Each branch on the
+remote will be exactly tracked by theses branches. You should NEVER do
+work on these remote tracking branches. You only ever do work in a
+local branch. Local branches can be configured to automerge (on pull)
+from a designated remote tracking branch. This is the case with the
+default branch C<blead> which will be configured to merge from the
+remote tracking branch C<origin/blead>.
+
You can see recent commits:
% git log
-And pull new changes from the repository:
+And pull new changes from the repository, and update your local
+repository (must be clean first)
% git pull
+Assuming we are on the branch C<blead> immediately after a pull, this
+command would be more or less equivalent to:
+
+ % git fetch
+ % git merge origin/blead
+
+In fact if you want to update your local repository without touching
+your working directory you do:
+
+ % git fetch
+
+And if you want to update your remote-tracking branches for all defined
+remotes simultaneously you can do
+
+ % git remote update
+
+Neither of these last two commands will update your working directory,
+however both will update the remote-tracking branches in your
+repository.
+
To switch to another branch:
% git checkout origin/maint-5.8-dor
+To make a local branch of a remote branch:
+
+ % git checkout -b maint-5.10 origin/maint-5.10
+
To switch back to blead:
% git checkout blead
+=head2 FINDING OUT YOUR STATUS
+
+The most common git command you will use will probably be
+
+ % git status
+
+This command will produce as output a description of the current state
+of the repository, including modified files and unignored untracked
+files, and in addition it will show things like what files have been
+staged for the next commit, and usually some useful information about
+how to change things. For instance the following:
+
+ $ git status
+ # On branch blead
+ # Your branch is ahead of 'origin/blead' by 1 commit.
+ #
+ # Changes to be committed:
+ # (use "git reset HEAD <file>..." to unstage)
+ #
+ # modified: pod/perlrepository.pod
+ #
+ # Changed but not updated:
+ # (use "git add <file>..." to update what will be committed)
+ #
+ # modified: pod/perlrepository.pod
+ #
+ # Untracked files:
+ # (use "git add <file>..." to include in what will be committed)
+ #
+ # deliberate.untracked
+
+This shows that there were changes to this document staged for commit,
+and that there were further changes in the working directory not yet
+staged. It also shows that there was an untracked file in the working
+directory, and as you can see shows how to change all of this. It also
+shows that there is one commit on the working branch C<blead> which has
+not been pushed to the C<origin> remote yet. B<NOTE>: that this output
+is also what you see as a template if you do not provide a message to
+C<git commit>.
+
+Assuming we commit all the mentioned changes above:
+
+ % git commit -a -m'explain git status and stuff about remotes'
+ Created commit daf8e63: explain git status and stuff about remotes
+ 1 files changed, 83 insertions(+), 3 deletions(-)
+
+We can re-run git status and see something like this:
+
+ % git status
+ # On branch blead
+ # Your branch is ahead of 'origin/blead' by 2 commits.
+ #
+ # Untracked files:
+ # (use "git add <file>..." to include in what will be committed)
+ #
+ # deliberate.untracked
+ nothing added to commit but untracked files present (use "git add" to track)
+
+
+When in doubt, before you do anything else, check your status and read
+it carefully, many questions are answered directly by the git status
+output.
+
=head1 SUBMITTING A PATCH
If you have a patch in mind for Perl, you should first get a copy of
% cd perl-git
-First we need to create a temporary new branch for these changes and
-switch into it:
+Alternatively, if you already have a Perl repository, you should ensure
+that you're on the I<blead> branch, and your repository is up to date:
+
+ % git checkout blead
+ % git pull
+
+It's preferable to patch against the latest blead version, since this
+is where new development occurs for all changes other than critical bug
+fixes. Critical bug fix patches should be made against the relevant
+maint branches, or should be submitted with a note indicating all the
+branches where the fix should be applied.
+
+Now that we have everything up to date, we need to create a temporary
+new branch for these changes and switch into it:
+
+ % git checkout -b orange
+
+which is the short form of
% git branch orange
% git checkout orange
You can see what files are changed:
% git status
- # On branch blead
+ # On branch orange
# Changes to be committed:
# (use "git reset HEAD <file>..." to unstage)
#
Now commit your change locally:
- % git add AUTHORS
- % git commit -m 'Rename Leon Brocard to Orange Brocard'
+ % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
1 files changed, 1 insertions(+), 1 deletions(-)
+You can examine your last commit with:
+
+ % git show HEAD
+
+and if you are not happy with either the description or the patch
+itself you can fix it up by editing the files once more and then issue:
+
+ % git commit -a --amend
+
Now you should create a patch file for all your local changes:
% git format-patch origin
0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
You should now send an email to perl5-porters@perl.org with a
-description of your changes, and attach this patch file as an
+description of your changes, and include this patch file as an
attachment.
If you want to delete your temporary branch, you may do so with:
% git branch -D orange
Deleted branch orange.
+=head2 A note on derived files
+
+Be aware that many files in the distribution are derivative--avoid
+patching them, because git won't see the changes to them, and the build
+process will overwrite them. Patch the originals instead. Most
+utilities (like perldoc) are in this category, i.e. patch
+utils/perldoc.PL rather than utils/perldoc. Similarly, don't create
+patches for files under $src_root/ext from their copies found in
+$install_root/lib. If you are unsure about the proper location of a
+file that may have gotten copied while building the source
+distribution, consult the C<MANIFEST>.
+
+=for XXX
+
+What should we recommend about binary files now? Do we need anything?
+
+=head2 Getting your patch accepted
+
+The first thing you should include with your patch is a description of
+the problem that the patch corrects. If it is a code patch (rather
+than a documentation patch) you should also include a small test case
+that illustrates the bug (a patch to an existing test file is
+preferred).
+
+If you are submitting a code patch there are several other things that
+you need to do.
+
+=over 4
+
+=item Comments, Comments, Comments
+
+Be sure to adequately comment your code. While commenting every line
+is unnecessary, anything that takes advantage of side effects of
+operators, that creates changes that will be felt outside of the
+function being patched, or that others may find confusing should be
+documented. If you are going to err, it is better to err on the side
+of adding too many comments than too few.
+
+=item Style
+
+In general, please follow the particular style of the code you are
+patching.
+
+In particular, follow these general guidelines for patching Perl
+sources:
+
+ 8-wide tabs (no exceptions!)
+ 4-wide indents for code, 2-wide indents for nested CPP #defines
+ try hard not to exceed 79-columns
+ ANSI C prototypes
+ uncuddled elses and "K&R" style for indenting control constructs
+ no C++ style (//) comments
+ mark places that need to be revisited with XXX (and revisit often!)
+ opening brace lines up with "if" when conditional spans multiple
+ lines; should be at end-of-line otherwise
+ in function definitions, name starts in column 0 (return value is on
+ previous line)
+ single space after keywords that are followed by parens, no space
+ between function name and following paren
+ avoid assignments in conditionals, but if they're unavoidable, use
+ extra paren, e.g. "if (a && (b = c)) ..."
+ "return foo;" rather than "return(foo);"
+ "if (!foo) ..." rather than "if (foo == FALSE) ..." etc.
+
+=item Testsuite
+
+When submitting a patch you should make every effort to also include an
+addition to perl's regression tests to properly exercise your patch.
+Your testsuite additions should generally follow these guidelines
+(courtesy of Gurusamy Sarathy <gsar@activestate.com>):
+
+ Know what you're testing. Read the docs, and the source.
+ Tend to fail, not succeed.
+ Interpret results strictly.
+ Use unrelated features (this will flush out bizarre interactions).
+ Use non-standard idioms (otherwise you are not testing TIMTOWTDI).
+ Avoid using hardcoded test numbers whenever possible (the
+ EXPECTED/GOT found in t/op/tie.t is much more maintainable,
+ and gives better failure reports).
+ Give meaningful error messages when a test fails.
+ Avoid using qx// and system() unless you are testing for them. If you
+ do use them, make sure that you cover _all_ perl platforms.
+ Unlink any temporary files you create.
+ Promote unforeseen warnings to errors with $SIG{__WARN__}.
+ Be sure to use the libraries and modules shipped with the version
+ being tested, not those that were already installed.
+ Add comments to the code explaining what you are testing for.
+ Make updating the '1..42' string unnecessary. Or make sure that
+ you update it.
+ Test _all_ behaviors of a given operator, library, or function:
+ - All optional arguments
+ - Return values in various contexts (boolean, scalar, list, lvalue)
+ - Use both global and lexical variables
+ - Don't forget the exceptional, pathological cases.
+
+=back
+
=head1 ACCEPTING A PATCH
If you have received a patch file generated using the above section,
First we need to create a temporary new branch for these changes and
switch into it:
- % git branch experimental
- % git checkout experimental
+ % git checkout -b experimental
-Now we should apply the patch:
+Patches that were formatted by C<git format-patch> are applied with
+C<git am>:
% git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
Applying Rename Leon Brocard to Orange Brocard
+If just a raw diff is provided, it is also possible use this two-step
+process:
+
+ % git apply bugfix.diff
+ % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"
+
Now we can inspect the change:
- % git log
+ % git show HEAD
commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
Author: Leon Brocard <acme@astray.com>
Date: Fri Dec 19 17:02:59 2008 +0000
Rename Leon Brocard to Orange Brocard
- ...
- % git diff blead
diff --git a/AUTHORS b/AUTHORS
index 293dd70..722c93e 100644
--- a/AUTHORS
then merge it into blead then push it out to the main repository:
% git checkout blead
- % git pull . experimental
+ % git merge experimental
% git push
If you want to delete your temporary branch, you may do so with:
If you are sure you want to delete it, run 'git branch -D experimental'.
% git branch -D experimental
Deleted branch experimental.
+
+=head1 CLEANING A WORKING DIRECTORY
+
+The command C<git clean> can with varying arguments be used as a
+replacement for C<make clean>.
+
+To reset your working directory to a pristine condition you can do:
+
+ git clean -dxf
+
+However, be aware this will delete ALL untracked content. You can use
+
+ git clean -Xf
+
+to remove all ignored untracked files, such as build and test
+byproduct, but leave any manually created files alone.
+
+If you only want to cancel some uncommitted edits, you can use C<git
+checkout> and give it a list of files to be reverted, or C<git checkout
+-f> to revert them all.
+
+If you want to cancel one or several commits, you can use C<git reset>.
+
+=head1 BISECTING
+
+C<git> provides a built-in way to determine, with a binary search in
+the history, which commit should be blamed for introducing a given bug.
+
+Suppose that we have a script F<~/testcase.pl> that exits with C<0>
+when some behaviour is correct, and with C<1> when it's faulty. We need
+an helper script that automates building C<perl> and running the
+testcase:
+
+ % cat ~/run
+ #!/bin/sh
+ git clean -dxf
+ # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
+ sh Configure -des -Dusedevel -Doptimize="-g"
+ test -f config.sh || exit 125
+ # Correct makefile for newer GNU gcc
+ perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
+ # if you just need miniperl, replace test_prep with miniperl
+ make -j4 test_prep
+ -x ./perl || exit 125
+ ./perl -Ilib ~/testcase.pl
+ ret=$?
+ git clean -dxf
+ exit $ret
+
+This script may return C<125> to indicate that the corresponding commit
+should be skipped. Otherwise, it returns the status of
+F<~/testcase.pl>.
+
+We first enter in bisect mode with:
+
+ % git bisect start
+
+For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
+C<git> will learn about this when you enter:
+
+ % git bisect bad
+ % git bisect good perl-5.10.0
+ Bisecting: 853 revisions left to test after this
+
+This results in checking out the median commit between C<HEAD> and
+C<perl-5.10.0>. We can then run the bisecting process with:
+
+ % git bisect run ~/run
+
+When the first bad commit is isolated, C<git bisect> will tell you so:
+
+ ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
+ commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
+ Author: Dave Mitchell <davem@fdisolutions.com>
+ Date: Sat Feb 9 14:56:23 2008 +0000
+
+ [perl #49472] Attributes + Unknown Error
+ ...
+
+ bisect run success
+
+You can peek into the bisecting process with C<git bisect log> and
+C<git bisect visualize>. C<git bisect reset> will get you out of bisect
+mode.
+
+Please note that the first C<good> state must be an ancestor of the
+first C<bad> state. If you want to search for the commit that I<solved>
+some bug, you have to negate your test case (i.e. exit with C<1> if OK
+and C<0> if not) and still mark the lower bound as C<good> and the
+upper as C<bad>. The "first bad commit" has then to be understood as
+the "first commit where the bug is solved".
+
+C<git help bisect> has much more information on how you can tweak your
+binary searches.
+
+=head1 SUBMITTING A PATCH VIA GITHUB
+
+GitHub is a website that makes it easy to fork and publish projects
+with Git. First you should set up a GitHub account and log in.
+
+Perl's git repository is mirrored on GitHub at this page:
+
+ http://github.com/github/perl/tree/blead
+
+Visit the page and click the "fork" button. This clones the Perl git
+repository for you and provides you with "Your Clone URL" from which
+you should clone:
+
+ % git clone git@github.com:USERNAME/perl.git perl-github
+
+We shall make the same patch as above, creating a new branch:
+
+ % cd perl-github
+ % git remote add upstream git://github.com/github/perl.git
+ % git pull upstream blead
+ % git checkout -b orange
+ % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
+ % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
+ % git push origin orange
+
+The orange branch has been pushed to GitHub, so you should now send an
+email to perl5-porters@perl.org with a description of your changes and
+the following information:
+
+ http://github.com/USERNAME/perl/tree/orange
+ git@github.com:USERNAME/perl.git branch orange
+
+=head1 MERGING FROM A BRANCH VIA GITHUB
+
+If someone has provided a branch via GitHub and you are a committer,
+you should use the following in your perl-ssh directory:
+
+ % git remote add dandv git://github.com/dandv/perl.git
+ % git fetch
+
+Now you can see the differences between the branch and blead:
+
+ % git diff dandv/blead
+
+And you can see the commits:
+
+ % git log dandv/blead
+
+If you approve of a specific commit, you can cherry pick it:
+
+ % git cherry-pick 3adac458cb1c1d41af47fc66e67b49c8dec2323f
+
+Or you could just merge the whole branch if you like it all:
+
+ % git merge dandv/blead
+
+And then push back to the repository:
+
+ % git push
+
+=head1 COMMITTING TO MAINTENANCE VERSIONS
+
+Maintenance versions should only be altered to add critical bug fixes.
+
+To commit to a maintenance version of perl, you need to create a local
+tracking branch:
+
+ % git checkout --track -b maint-5.005 origin/maint-5.005
+
+This creates a local branch named C<maint-5.005>, which tracks the
+remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
+and push as before.
+
+You can also cherry-pick commits from blead and another branch, by
+using the C<git cherry-pick> command. It is recommended to use the
+B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
+original commit in the new commit message.
+
+=head1 SEE ALSO
+
+The git documentation, accessible via C<git help command>.
+
projects / p5sagit/p5-mst-13.2.git / blobdiff