diff options
Diffstat (limited to 'third_party/git/Documentation/MyFirstContribution.txt')
| -rw-r--r-- | third_party/git/Documentation/MyFirstContribution.txt | 1217 |
1 files changed, 0 insertions, 1217 deletions
diff --git a/third_party/git/Documentation/MyFirstContribution.txt b/third_party/git/Documentation/MyFirstContribution.txt deleted file mode 100644 index 4f85a089ef9d..000000000000 --- a/third_party/git/Documentation/MyFirstContribution.txt +++ /dev/null @@ -1,1217 +0,0 @@ -My First Contribution to the Git Project -======================================== -:sectanchors: - -[[summary]] -== Summary - -This is a tutorial demonstrating the end-to-end workflow of creating a change to -the Git tree, sending it for review, and making changes based on comments. - -[[prerequisites]] -=== Prerequisites - -This tutorial assumes you're already fairly familiar with using Git to manage -source code. The Git workflow steps will largely remain unexplained. - -[[related-reading]] -=== Related Reading - -This tutorial aims to summarize the following documents, but the reader may find -useful additional context: - -- `Documentation/SubmittingPatches` -- `Documentation/howto/new-command.txt` - -[[getting-help]] -=== Getting Help - -If you get stuck, you can seek help in the following places. - -==== git@vger.kernel.org - -This is the main Git project mailing list where code reviews, version -announcements, design discussions, and more take place. Those interested in -contributing are welcome to post questions here. The Git list requires -plain-text-only emails and prefers inline and bottom-posting when replying to -mail; you will be CC'd in all replies to you. Optionally, you can subscribe to -the list by sending an email to majordomo@vger.kernel.org with "subscribe git" -in the body. The https://lore.kernel.org/git[archive] of this mailing list is -available to view in a browser. - -==== https://groups.google.com/forum/#!forum/git-mentoring[git-mentoring@googlegroups.com] - -This mailing list is targeted to new contributors and was created as a place to -post questions and receive answers outside of the public eye of the main list. -Veteran contributors who are especially interested in helping mentor newcomers -are present on the list. In order to avoid search indexers, group membership is -required to view messages; anyone can join and no approval is required. - -==== https://webchat.freenode.net/#git-devel[#git-devel] on Freenode - -This IRC channel is for conversations between Git contributors. If someone is -currently online and knows the answer to your question, you can receive help -in real time. Otherwise, you can read the -https://colabti.org/irclogger/irclogger_logs/git-devel[scrollback] to see -whether someone answered you. IRC does not allow offline private messaging, so -if you try to private message someone and then log out of IRC, they cannot -respond to you. It's better to ask your questions in the channel so that you -can be answered if you disconnect and so that others can learn from the -conversation. - -[[getting-started]] -== Getting Started - -[[cloning]] -=== Clone the Git Repository - -Git is mirrored in a number of locations. Clone the repository from one of them; -https://git-scm.com/downloads suggests one of the best places to clone from is -the mirror on GitHub. - ----- -$ git clone https://github.com/git/git git -$ cd git ----- - -[[dependencies]] -=== Installing Dependencies - -To build Git from source, you need to have a handful of dependencies installed -on your system. For a hint of what's needed, you can take a look at -`INSTALL`, paying close attention to the section about Git's dependencies on -external programs and libraries. That document mentions a way to "test-drive" -our freshly built Git without installing; that's the method we'll be using in -this tutorial. - -Make sure that your environment has everything you need by building your brand -new clone of Git from the above step: - ----- -$ make ----- - -NOTE: The Git build is parallelizable. `-j#` is not included above but you can -use it as you prefer, here and elsewhere. - -[[identify-problem]] -=== Identify Problem to Solve - -//// -Use + to indicate fixed-width here; couldn't get ` to work nicely with the -quotes around "Pony Saying 'Um, Hello'". -//// -In this tutorial, we will add a new command, +git psuh+, short for ``Pony Saying -`Um, Hello''' - a feature which has gone unimplemented despite a high frequency -of invocation during users' typical daily workflow. - -(We've seen some other effort in this space with the implementation of popular -commands such as `sl`.) - -[[setup-workspace]] -=== Set Up Your Workspace - -Let's start by making a development branch to work on our changes. Per -`Documentation/SubmittingPatches`, since a brand new command is a new feature, -it's fine to base your work on `master`. However, in the future for bugfixes, -etc., you should check that document and base it on the appropriate branch. - -For the purposes of this document, we will base all our work on the `master` -branch of the upstream project. Create the `psuh` branch you will use for -development like so: - ----- -$ git checkout -b psuh origin/master ----- - -We'll make a number of commits here in order to demonstrate how to send a topic -with multiple patches up for review simultaneously. - -[[code-it-up]] -== Code It Up! - -NOTE: A reference implementation can be found at -https://github.com/nasamuffin/git/tree/psuh. - -[[add-new-command]] -=== Adding a New Command - -Lots of the subcommands are written as builtins, which means they are -implemented in C and compiled into the main `git` executable. Implementing the -very simple `psuh` command as a built-in will demonstrate the structure of the -codebase, the internal API, and the process of working together as a contributor -with the reviewers and maintainer to integrate this change into the system. - -Built-in subcommands are typically implemented in a function named "cmd_" -followed by the name of the subcommand, in a source file named after the -subcommand and contained within `builtin/`. So it makes sense to implement your -command in `builtin/psuh.c`. Create that file, and within it, write the entry -point for your command in a function matching the style and signature: - ----- -int cmd_psuh(int argc, const char **argv, const char *prefix) ----- - -We'll also need to add the declaration of psuh; open up `builtin.h`, find the -declaration for `cmd_pull`, and add a new line for `psuh` immediately before it, -in order to keep the declarations alphabetically sorted: - ----- -int cmd_psuh(int argc, const char **argv, const char *prefix); ----- - -Be sure to `#include "builtin.h"` in your `psuh.c`. - -Go ahead and add some throwaway printf to that function. This is a decent -starting point as we can now add build rules and register the command. - -NOTE: Your throwaway text, as well as much of the text you will be adding over -the course of this tutorial, is user-facing. That means it needs to be -localizable. Take a look at `po/README` under "Marking strings for translation". -Throughout the tutorial, we will mark strings for translation as necessary; you -should also do so when writing your user-facing commands in the future. - ----- -int cmd_psuh(int argc, const char **argv, const char *prefix) -{ - printf(_("Pony saying hello goes here.\n")); - return 0; -} ----- - -Let's try to build it. Open `Makefile`, find where `builtin/pull.o` is added -to `BUILTIN_OBJS`, and add `builtin/psuh.o` in the same way next to it in -alphabetical order. Once you've done so, move to the top-level directory and -build simply with `make`. Also add the `DEVELOPER=1` variable to turn on -some additional warnings: - ----- -$ echo DEVELOPER=1 >config.mak -$ make ----- - -NOTE: When you are developing the Git project, it's preferred that you use the -`DEVELOPER` flag; if there's some reason it doesn't work for you, you can turn -it off, but it's a good idea to mention the problem to the mailing list. - -Great, now your new command builds happily on its own. But nobody invokes it. -Let's change that. - -The list of commands lives in `git.c`. We can register a new command by adding -a `cmd_struct` to the `commands[]` array. `struct cmd_struct` takes a string -with the command name, a function pointer to the command implementation, and a -setup option flag. For now, let's keep mimicking `push`. Find the line where -`cmd_push` is registered, copy it, and modify it for `cmd_psuh`, placing the new -line in alphabetical order (immediately before `cmd_pull`). - -The options are documented in `builtin.h` under "Adding a new built-in." Since -we hope to print some data about the user's current workspace context later, -we need a Git directory, so choose `RUN_SETUP` as your only option. - -Go ahead and build again. You should see a clean build, so let's kick the tires -and see if it works. There's a binary you can use to test with in the -`bin-wrappers` directory. - ----- -$ ./bin-wrappers/git psuh ----- - -Check it out! You've got a command! Nice work! Let's commit this. - -`git status` reveals modified `Makefile`, `builtin.h`, and `git.c` as well as -untracked `builtin/psuh.c` and `git-psuh`. First, let's take care of the binary, -which should be ignored. Open `.gitignore` in your editor, find `/git-pull`, and -add an entry for your new command in alphabetical order: - ----- -... -/git-prune-packed -/git-psuh -/git-pull -/git-push -/git-quiltimport -/git-range-diff -... ----- - -Checking `git status` again should show that `git-psuh` has been removed from -the untracked list and `.gitignore` has been added to the modified list. Now we -can stage and commit: - ----- -$ git add Makefile builtin.h builtin/psuh.c git.c .gitignore -$ git commit -s ----- - -You will be presented with your editor in order to write a commit message. Start -the commit with a 50-column or less subject line, including the name of the -component you're working on, followed by a blank line (always required) and then -the body of your commit message, which should provide the bulk of the context. -Remember to be explicit and provide the "Why" of your change, especially if it -couldn't easily be understood from your diff. When editing your commit message, -don't remove the Signed-off-by line which was added by `-s` above. - ----- -psuh: add a built-in by popular demand - -Internal metrics indicate this is a command many users expect to be -present. So here's an implementation to help drive customer -satisfaction and engagement: a pony which doubtfully greets the user, -or, a Pony Saying "Um, Hello" (PSUH). - -This commit message is intentionally formatted to 72 columns per line, -starts with a single line as "commit message subject" that is written as -if to command the codebase to do something (add this, teach a command -that). The body of the message is designed to add information about the -commit that is not readily deduced from reading the associated diff, -such as answering the question "why?". - -Signed-off-by: A U Thor <author@example.com> ----- - -Go ahead and inspect your new commit with `git show`. "psuh:" indicates you -have modified mainly the `psuh` command. The subject line gives readers an idea -of what you've changed. The sign-off line (`-s`) indicates that you agree to -the Developer's Certificate of Origin 1.1 (see the -`Documentation/SubmittingPatches` +++[[dco]]+++ header). - -For the remainder of the tutorial, the subject line only will be listed for the -sake of brevity. However, fully-fleshed example commit messages are available -on the reference implementation linked at the top of this document. - -[[implementation]] -=== Implementation - -It's probably useful to do at least something besides printing out a string. -Let's start by having a look at everything we get. - -Modify your `cmd_psuh` implementation to dump the args you're passed, keeping -existing `printf()` calls in place: - ----- - int i; - - ... - - printf(Q_("Your args (there is %d):\n", - "Your args (there are %d):\n", - argc), - argc); - for (i = 0; i < argc; i++) - printf("%d: %s\n", i, argv[i]); - - printf(_("Your current working directory:\n<top-level>%s%s\n"), - prefix ? "/" : "", prefix ? prefix : ""); - ----- - -Build and try it. As you may expect, there's pretty much just whatever we give -on the command line, including the name of our command. (If `prefix` is empty -for you, try `cd Documentation/ && ../bin-wrappers/git psuh`). That's not so -helpful. So what other context can we get? - -Add a line to `#include "config.h"`. Then, add the following bits to the -function body: - ----- - const char *cfg_name; - -... - - git_config(git_default_config, NULL); - if (git_config_get_string_tmp("user.name", &cfg_name) > 0) - printf(_("No name is found in config\n")); - else - printf(_("Your name: %s\n"), cfg_name); ----- - -`git_config()` will grab the configuration from config files known to Git and -apply standard precedence rules. `git_config_get_string_tmp()` will look up -a specific key ("user.name") and give you the value. There are a number of -single-key lookup functions like this one; you can see them all (and more info -about how to use `git_config()`) in `Documentation/technical/api-config.txt`. - -You should see that the name printed matches the one you see when you run: - ----- -$ git config --get user.name ----- - -Great! Now we know how to check for values in the Git config. Let's commit this -too, so we don't lose our progress. - ----- -$ git add builtin/psuh.c -$ git commit -sm "psuh: show parameters & config opts" ----- - -NOTE: Again, the above is for sake of brevity in this tutorial. In a real change -you should not use `-m` but instead use the editor to write a meaningful -message. - -Still, it'd be nice to know what the user's working context is like. Let's see -if we can print the name of the user's current branch. We can mimic the -`git status` implementation; the printer is located in `wt-status.c` and we can -see that the branch is held in a `struct wt_status`. - -`wt_status_print()` gets invoked by `cmd_status()` in `builtin/commit.c`. -Looking at that implementation we see the status config being populated like so: - ----- -status_init_config(&s, git_status_config); ----- - -But as we drill down, we can find that `status_init_config()` wraps a call -to `git_config()`. Let's modify the code we wrote in the previous commit. - -Be sure to include the header to allow you to use `struct wt_status`: ----- -#include "wt-status.h" ----- - -Then modify your `cmd_psuh` implementation to declare your `struct wt_status`, -prepare it, and print its contents: - ----- - struct wt_status status; - -... - - wt_status_prepare(the_repository, &status); - git_config(git_default_config, &status); - -... - - printf(_("Your current branch: %s\n"), status.branch); ----- - -Run it again. Check it out - here's the (verbose) name of your current branch! - -Let's commit this as well. - ----- -$ git add builtin/psuh.c -$ git commit -sm "psuh: print the current branch" ----- - -Now let's see if we can get some info about a specific commit. - -Luckily, there are some helpers for us here. `commit.h` has a function called -`lookup_commit_reference_by_name` to which we can simply provide a hardcoded -string; `pretty.h` has an extremely handy `pp_commit_easy()` call which doesn't -require a full format object to be passed. - -Add the following includes: - ----- -#include "commit.h" -#include "pretty.h" ----- - -Then, add the following lines within your implementation of `cmd_psuh()` near -the declarations and the logic, respectively. - ----- - struct commit *c = NULL; - struct strbuf commitline = STRBUF_INIT; - -... - - c = lookup_commit_reference_by_name("origin/master"); - - if (c != NULL) { - pp_commit_easy(CMIT_FMT_ONELINE, c, &commitline); - printf(_("Current commit: %s\n"), commitline.buf); - } ----- - -The `struct strbuf` provides some safety belts to your basic `char*`, one of -which is a length member to prevent buffer overruns. It needs to be initialized -nicely with `STRBUF_INIT`. Keep it in mind when you need to pass around `char*`. - -`lookup_commit_reference_by_name` resolves the name you pass it, so you can play -with the value there and see what kind of things you can come up with. - -`pp_commit_easy` is a convenience wrapper in `pretty.h` that takes a single -format enum shorthand, rather than an entire format struct. It then -pretty-prints the commit according to that shorthand. These are similar to the -formats available with `--pretty=FOO` in many Git commands. - -Build it and run, and if you're using the same name in the example, you should -see the subject line of the most recent commit in `origin/master` that you know -about. Neat! Let's commit that as well. - ----- -$ git add builtin/psuh.c -$ git commit -sm "psuh: display the top of origin/master" ----- - -[[add-documentation]] -=== Adding Documentation - -Awesome! You've got a fantastic new command that you're ready to share with the -community. But hang on just a minute - this isn't very user-friendly. Run the -following: - ----- -$ ./bin-wrappers/git help psuh ----- - -Your new command is undocumented! Let's fix that. - -Take a look at `Documentation/git-*.txt`. These are the manpages for the -subcommands that Git knows about. You can open these up and take a look to get -acquainted with the format, but then go ahead and make a new file -`Documentation/git-psuh.txt`. Like with most of the documentation in the Git -project, help pages are written with AsciiDoc (see CodingGuidelines, "Writing -Documentation" section). Use the following template to fill out your own -manpage: - -// Surprisingly difficult to embed AsciiDoc source within AsciiDoc. -[listing] -.... -git-psuh(1) -=========== - -NAME ----- -git-psuh - Delight users' typo with a shy horse - - -SYNOPSIS --------- -[verse] -'git-psuh [<arg>...]' - -DESCRIPTION ------------ -... - -OPTIONS[[OPTIONS]] ------------------- -... - -OUTPUT ------- -... - -GIT ---- -Part of the linkgit:git[1] suite -.... - -The most important pieces of this to note are the file header, underlined by =, -the NAME section, and the SYNOPSIS, which would normally contain the grammar if -your command took arguments. Try to use well-established manpage headers so your -documentation is consistent with other Git and UNIX manpages; this makes life -easier for your user, who can skip to the section they know contains the -information they need. - -Now that you've written your manpage, you'll need to build it explicitly. We -convert your AsciiDoc to troff which is man-readable like so: - ----- -$ make all doc -$ man Documentation/git-psuh.1 ----- - -or - ----- -$ make -C Documentation/ git-psuh.1 -$ man Documentation/git-psuh.1 ----- - -NOTE: You may need to install the package `asciidoc` to get this to work. - -While this isn't as satisfying as running through `git help`, you can at least -check that your help page looks right. - -You can also check that the documentation coverage is good (that is, the project -sees that your command has been implemented as well as documented) by running -`make check-docs` from the top-level. - -Go ahead and commit your new documentation change. - -[[add-usage]] -=== Adding Usage Text - -Try and run `./bin-wrappers/git psuh -h`. Your command should crash at the end. -That's because `-h` is a special case which your command should handle by -printing usage. - -Take a look at `Documentation/technical/api-parse-options.txt`. This is a handy -tool for pulling out options you need to be able to handle, and it takes a -usage string. - -In order to use it, we'll need to prepare a NULL-terminated array of usage -strings and a `builtin_psuh_options` array. - -Add a line to `#include "parse-options.h"`. - -At global scope, add your array of usage strings: - ----- -static const char * const psuh_usage[] = { - N_("git psuh [<arg>...]"), - NULL, -}; ----- - -Then, within your `cmd_psuh()` implementation, we can declare and populate our -`option` struct. Ours is pretty boring but you can add more to it if you want to -explore `parse_options()` in more detail: - ----- - struct option options[] = { - OPT_END() - }; ----- - -Finally, before you print your args and prefix, add the call to -`parse-options()`: - ----- - argc = parse_options(argc, argv, prefix, options, psuh_usage, 0); ----- - -This call will modify your `argv` parameter. It will strip the options you -specified in `options` from `argv` and the locations pointed to from `options` -entries will be updated. Be sure to replace your `argc` with the result from -`parse_options()`, or you will be confused if you try to parse `argv` later. - -It's worth noting the special argument `--`. As you may be aware, many Unix -commands use `--` to indicate "end of named parameters" - all parameters after -the `--` are interpreted merely as positional arguments. (This can be handy if -you want to pass as a parameter something which would usually be interpreted as -a flag.) `parse_options()` will terminate parsing when it reaches `--` and give -you the rest of the options afterwards, untouched. - -Now that you have a usage hint, you can teach Git how to show it in the general -command list shown by `git help git` or `git help -a`, which is generated from -`command-list.txt`. Find the line for 'git-pull' so you can add your 'git-psuh' -line above it in alphabetical order. Now, we can add some attributes about the -command which impacts where it shows up in the aforementioned help commands. The -top of `command-list.txt` shares some information about what each attribute -means; in those help pages, the commands are sorted according to these -attributes. `git psuh` is user-facing, or porcelain - so we will mark it as -"mainporcelain". For "mainporcelain" commands, the comments at the top of -`command-list.txt` indicate we can also optionally add an attribute from another -list; since `git psuh` shows some information about the user's workspace but -doesn't modify anything, let's mark it as "info". Make sure to keep your -attributes in the same style as the rest of `command-list.txt` using spaces to -align and delineate them: - ----- -git-prune-packed plumbingmanipulators -git-psuh mainporcelain info -git-pull mainporcelain remote -git-push mainporcelain remote ----- - -Build again. Now, when you run with `-h`, you should see your usage printed and -your command terminated before anything else interesting happens. Great! - -Go ahead and commit this one, too. - -[[testing]] -== Testing - -It's important to test your code - even for a little toy command like this one. -Moreover, your patch won't be accepted into the Git tree without tests. Your -tests should: - -* Illustrate the current behavior of the feature -* Prove the current behavior matches the expected behavior -* Ensure the externally-visible behavior isn't broken in later changes - -So let's write some tests. - -Related reading: `t/README` - -[[overview-test-structure]] -=== Overview of Testing Structure - -The tests in Git live in `t/` and are named with a 4-digit decimal number using -the schema shown in the Naming Tests section of `t/README`. - -[[write-new-test]] -=== Writing Your Test - -Since this a toy command, let's go ahead and name the test with t9999. However, -as many of the family/subcmd combinations are full, best practice seems to be -to find a command close enough to the one you've added and share its naming -space. - -Create a new file `t/t9999-psuh-tutorial.sh`. Begin with the header as so (see -"Writing Tests" and "Source 'test-lib.sh'" in `t/README`): - ----- -#!/bin/sh - -test_description='git-psuh test - -This test runs git-psuh and makes sure it does not crash.' - -. ./test-lib.sh ----- - -Tests are framed inside of a `test_expect_success` in order to output TAP -formatted results. Let's make sure that `git psuh` doesn't exit poorly and does -mention the right animal somewhere: - ----- -test_expect_success 'runs correctly with no args and good output' ' - git psuh >actual && - test_i18ngrep Pony actual -' ----- - -Indicate that you've run everything you wanted by adding the following at the -bottom of your script: - ----- -test_done ----- - -Make sure you mark your test script executable: - ----- -$ chmod +x t/t9999-psuh-tutorial.sh ----- - -You can get an idea of whether you created your new test script successfully -by running `make -C t test-lint`, which will check for things like test number -uniqueness, executable bit, and so on. - -[[local-test]] -=== Running Locally - -Let's try and run locally: - ----- -$ make -$ cd t/ && prove t9999-psuh-tutorial.sh ----- - -You can run the full test suite and ensure `git-psuh` didn't break anything: - ----- -$ cd t/ -$ prove -j$(nproc) --shuffle t[0-9]*.sh ----- - -NOTE: You can also do this with `make test` or use any testing harness which can -speak TAP. `prove` can run concurrently. `shuffle` randomizes the order the -tests are run in, which makes them resilient against unwanted inter-test -dependencies. `prove` also makes the output nicer. - -Go ahead and commit this change, as well. - -[[ready-to-share]] -== Getting Ready to Share - -You may have noticed already that the Git project performs its code reviews via -emailed patches, which are then applied by the maintainer when they are ready -and approved by the community. The Git project does not accept patches from -pull requests, and the patches emailed for review need to be formatted a -specific way. At this point the tutorial diverges, in order to demonstrate two -different methods of formatting your patchset and getting it reviewed. - -The first method to be covered is GitGitGadget, which is useful for those -already familiar with GitHub's common pull request workflow. This method -requires a GitHub account. - -The second method to be covered is `git send-email`, which can give slightly -more fine-grained control over the emails to be sent. This method requires some -setup which can change depending on your system and will not be covered in this -tutorial. - -Regardless of which method you choose, your engagement with reviewers will be -the same; the review process will be covered after the sections on GitGitGadget -and `git send-email`. - -[[howto-ggg]] -== Sending Patches via GitGitGadget - -One option for sending patches is to follow a typical pull request workflow and -send your patches out via GitGitGadget. GitGitGadget is a tool created by -Johannes Schindelin to make life as a Git contributor easier for those used to -the GitHub PR workflow. It allows contributors to open pull requests against its -mirror of the Git project, and does some magic to turn the PR into a set of -emails and send them out for you. It also runs the Git continuous integration -suite for you. It's documented at http://gitgitgadget.github.io. - -[[create-fork]] -=== Forking `git/git` on GitHub - -Before you can send your patch off to be reviewed using GitGitGadget, you will -need to fork the Git project and upload your changes. First thing - make sure -you have a GitHub account. - -Head to the https://github.com/git/git[GitHub mirror] and look for the Fork -button. Place your fork wherever you deem appropriate and create it. - -[[upload-to-fork]] -=== Uploading to Your Own Fork - -To upload your branch to your own fork, you'll need to add the new fork as a -remote. You can use `git remote -v` to show the remotes you have added already. -From your new fork's page on GitHub, you can press "Clone or download" to get -the URL; then you need to run the following to add, replacing your own URL and -remote name for the examples provided: - ----- -$ git remote add remotename git@github.com:remotename/git.git ----- - -or to use the HTTPS URL: - ----- -$ git remote add remotename https://github.com/remotename/git/.git ----- - -Run `git remote -v` again and you should see the new remote showing up. -`git fetch remotename` (with the real name of your remote replaced) in order to -get ready to push. - -Next, double-check that you've been doing all your development in a new branch -by running `git branch`. If you didn't, now is a good time to move your new -commits to their own branch. - -As mentioned briefly at the beginning of this document, we are basing our work -on `master`, so go ahead and update as shown below, or using your preferred -workflow. - ----- -$ git checkout master -$ git pull -r -$ git rebase master psuh ----- - -Finally, you're ready to push your new topic branch! (Due to our branch and -command name choices, be careful when you type the command below.) - ----- -$ git push remotename psuh ----- - -Now you should be able to go and check out your newly created branch on GitHub. - -[[send-pr-ggg]] -=== Sending a PR to GitGitGadget - -In order to have your code tested and formatted for review, you need to start by -opening a Pull Request against `gitgitgadget/git`. Head to -https://github.com/gitgitgadget/git and open a PR either with the "New pull -request" button or the convenient "Compare & pull request" button that may -appear with the name of your newly pushed branch. - -Review the PR's title and description, as it's used by GitGitGadget as the cover -letter for your change. When you're happy, submit your pull request. - -[[run-ci-ggg]] -=== Running CI and Getting Ready to Send - -If it's your first time using GitGitGadget (which is likely, as you're using -this tutorial) then someone will need to give you permission to use the tool. -As mentioned in the GitGitGadget documentation, you just need someone who -already uses it to comment on your PR with `/allow <username>`. GitGitGadget -will automatically run your PRs through the CI even without the permission given -but you will not be able to `/submit` your changes until someone allows you to -use the tool. - -NOTE: You can typically find someone who can `/allow` you on GitGitGadget by -either examining recent pull requests where someone has been granted `/allow` -(https://github.com/gitgitgadget/git/pulls?utf8=%E2%9C%93&q=is%3Apr+is%3Aopen+%22%2Fallow%22[Search: -is:pr is:open "/allow"]), in which case both the author and the person who -granted the `/allow` can now `/allow` you, or by inquiring on the -https://webchat.freenode.net/#git-devel[#git-devel] IRC channel on Freenode -linking your pull request and asking for someone to `/allow` you. - -If the CI fails, you can update your changes with `git rebase -i` and push your -branch again: - ----- -$ git push -f remotename psuh ----- - -In fact, you should continue to make changes this way up until the point when -your patch is accepted into `next`. - -//// -TODO https://github.com/gitgitgadget/gitgitgadget/issues/83 -It'd be nice to be able to verify that the patch looks good before sending it -to everyone on Git mailing list. -[[check-work-ggg]] -=== Check Your Work -//// - -[[send-mail-ggg]] -=== Sending Your Patches - -Now that your CI is passing and someone has granted you permission to use -GitGitGadget with the `/allow` command, sending out for review is as simple as -commenting on your PR with `/submit`. - -[[responding-ggg]] -=== Updating With Comments - -Skip ahead to <<reviewing,Responding to Reviews>> for information on how to -reply to review comments you will receive on the mailing list. - -Once you have your branch again in the shape you want following all review -comments, you can submit again: - ----- -$ git push -f remotename psuh ----- - -Next, go look at your pull request against GitGitGadget; you should see the CI -has been kicked off again. Now while the CI is running is a good time for you -to modify your description at the top of the pull request thread; it will be -used again as the cover letter. You should use this space to describe what -has changed since your previous version, so that your reviewers have some idea -of what they're looking at. When the CI is done running, you can comment once -more with `/submit` - GitGitGadget will automatically add a v2 mark to your -changes. - -[[howto-git-send-email]] -== Sending Patches with `git send-email` - -If you don't want to use GitGitGadget, you can also use Git itself to mail your -patches. Some benefits of using Git this way include finer grained control of -subject line (for example, being able to use the tag [RFC PATCH] in the subject) -and being able to send a ``dry run'' mail to yourself to ensure it all looks -good before going out to the list. - -[[setup-git-send-email]] -=== Prerequisite: Setting Up `git send-email` - -Configuration for `send-email` can vary based on your operating system and email -provider, and so will not be covered in this tutorial, beyond stating that in -many distributions of Linux, `git-send-email` is not packaged alongside the -typical `git` install. You may need to install this additional package; there -are a number of resources online to help you do so. You will also need to -determine the right way to configure it to use your SMTP server; again, as this -configuration can change significantly based on your system and email setup, it -is out of scope for the context of this tutorial. - -[[format-patch]] -=== Preparing Initial Patchset - -Sending emails with Git is a two-part process; before you can prepare the emails -themselves, you'll need to prepare the patches. Luckily, this is pretty simple: - ----- -$ git format-patch --cover-letter -o psuh/ master..psuh ----- - -The `--cover-letter` parameter tells `format-patch` to create a cover letter -template for you. You will need to fill in the template before you're ready -to send - but for now, the template will be next to your other patches. - -The `-o psuh/` parameter tells `format-patch` to place the patch files into a -directory. This is useful because `git send-email` can take a directory and -send out all the patches from there. - -`master..psuh` tells `format-patch` to generate patches for the difference -between `master` and `psuh`. It will make one patch file per commit. After you -run, you can go have a look at each of the patches with your favorite text -editor and make sure everything looks alright; however, it's not recommended to -make code fixups via the patch file. It's a better idea to make the change the -normal way using `git rebase -i` or by adding a new commit than by modifying a -patch. - -NOTE: Optionally, you can also use the `--rfc` flag to prefix your patch subject -with ``[RFC PATCH]'' instead of ``[PATCH]''. RFC stands for ``request for -comments'' and indicates that while your code isn't quite ready for submission, -you'd like to begin the code review process. This can also be used when your -patch is a proposal, but you aren't sure whether the community wants to solve -the problem with that approach or not - to conduct a sort of design review. You -may also see on the list patches marked ``WIP'' - this means they are incomplete -but want reviewers to look at what they have so far. You can add this flag with -`--subject-prefix=WIP`. - -Check and make sure that your patches and cover letter template exist in the -directory you specified - you're nearly ready to send out your review! - -[[cover-letter]] -=== Preparing Email - -In addition to an email per patch, the Git community also expects your patches -to come with a cover letter, typically with a subject line [PATCH 0/x] (where -x is the number of patches you're sending). Since you invoked `format-patch` -with `--cover-letter`, you've already got a template ready. Open it up in your -favorite editor. - -You should see a number of headers present already. Check that your `From:` -header is correct. Then modify your `Subject:` to something which succinctly -covers the purpose of your entire topic branch, for example: - ----- -Subject: [PATCH 0/7] adding the 'psuh' command ----- - -Make sure you retain the ``[PATCH 0/X]'' part; that's what indicates to the Git -community that this email is the beginning of a review, and many reviewers -filter their email for this type of flag. - -You'll need to add some extra parameters when you invoke `git send-email` to add -the cover letter. - -Next you'll have to fill out the body of your cover letter. This is an important -component of change submission as it explains to the community from a high level -what you're trying to do, and why, in a way that's more apparent than just -looking at your diff. Be sure to explain anything your diff doesn't make clear -on its own. - -Here's an example body for `psuh`: - ----- -Our internal metrics indicate widespread interest in the command -git-psuh - that is, many users are trying to use it, but finding it is -unavailable, using some unknown workaround instead. - -The following handful of patches add the psuh command and implement some -handy features on top of it. - -This patchset is part of the MyFirstContribution tutorial and should not -be merged. ----- - -The template created by `git format-patch --cover-letter` includes a diffstat. -This gives reviewers a summary of what they're in for when reviewing your topic. -The one generated for `psuh` from the sample implementation looks like this: - ----- - Documentation/git-psuh.txt | 40 +++++++++++++++++++++ - Makefile | 1 + - builtin.h | 1 + - builtin/psuh.c | 73 ++++++++++++++++++++++++++++++++++++++ - git.c | 1 + - t/t9999-psuh-tutorial.sh | 12 +++++++ - 6 files changed, 128 insertions(+) - create mode 100644 Documentation/git-psuh.txt - create mode 100644 builtin/psuh.c - create mode 100755 t/t9999-psuh-tutorial.sh ----- - -Finally, the letter will include the version of Git used to generate the -patches. You can leave that string alone. - -[[sending-git-send-email]] -=== Sending Email - -At this point you should have a directory `psuh/` which is filled with your -patches and a cover letter. Time to mail it out! You can send it like this: - ----- -$ git send-email --to=target@example.com psuh/*.patch ----- - -NOTE: Check `git help send-email` for some other options which you may find -valuable, such as changing the Reply-to address or adding more CC and BCC lines. - -NOTE: When you are sending a real patch, it will go to git@vger.kernel.org - but -please don't send your patchset from the tutorial to the real mailing list! For -now, you can send it to yourself, to make sure you understand how it will look. - -After you run the command above, you will be presented with an interactive -prompt for each patch that's about to go out. This gives you one last chance to -edit or quit sending something (but again, don't edit code this way). Once you -press `y` or `a` at these prompts your emails will be sent! Congratulations! - -Awesome, now the community will drop everything and review your changes. (Just -kidding - be patient!) - -[[v2-git-send-email]] -=== Sending v2 - -Skip ahead to <<reviewing,Responding to Reviews>> for information on how to -handle comments from reviewers. Continue this section when your topic branch is -shaped the way you want it to look for your patchset v2. - -When you're ready with the next iteration of your patch, the process is fairly -similar. - -First, generate your v2 patches again: - ----- -$ git format-patch -v2 --cover-letter -o psuh/ master..psuh ----- - -This will add your v2 patches, all named like `v2-000n-my-commit-subject.patch`, -to the `psuh/` directory. You may notice that they are sitting alongside the v1 -patches; that's fine, but be careful when you are ready to send them. - -Edit your cover letter again. Now is a good time to mention what's different -between your last version and now, if it's something significant. You do not -need the exact same body in your second cover letter; focus on explaining to -reviewers the changes you've made that may not be as visible. - -You will also need to go and find the Message-Id of your previous cover letter. -You can either note it when you send the first series, from the output of `git -send-email`, or you can look it up on the -https://lore.kernel.org/git[mailing list]. Find your cover letter in the -archives, click on it, then click "permalink" or "raw" to reveal the Message-Id -header. It should match: - ----- -Message-Id: <foo.12345.author@example.com> ----- - -Your Message-Id is `<foo.12345.author@example.com>`. This example will be used -below as well; make sure to replace it with the correct Message-Id for your -**previous cover letter** - that is, if you're sending v2, use the Message-Id -from v1; if you're sending v3, use the Message-Id from v2. - -While you're looking at the email, you should also note who is CC'd, as it's -common practice in the mailing list to keep all CCs on a thread. You can add -these CC lines directly to your cover letter with a line like so in the header -(before the Subject line): - ----- -CC: author@example.com, Othe R <other@example.com> ----- - -Now send the emails again, paying close attention to which messages you pass in -to the command: - ----- -$ git send-email --to=target@example.com - --in-reply-to="<foo.12345.author@example.com>" - psuh/v2* ----- - -[[single-patch]] -=== Bonus Chapter: One-Patch Changes - -In some cases, your very small change may consist of only one patch. When that -happens, you only need to send one email. Your commit message should already be -meaningful and explain at a high level the purpose (what is happening and why) -of your patch, but if you need to supply even more context, you can do so below -the `---` in your patch. Take the example below, which was generated with `git -format-patch` on a single commit, and then edited to add the content between -the `---` and the diffstat. - ----- -From 1345bbb3f7ac74abde040c12e737204689a72723 Mon Sep 17 00:00:00 2001 -From: A U Thor <author@example.com> -Date: Thu, 18 Apr 2019 15:11:02 -0700 -Subject: [PATCH] README: change the grammar - -I think it looks better this way. This part of the commit message will -end up in the commit-log. - -Signed-off-by: A U Thor <author@example.com> ---- -Let's have a wild discussion about grammar on the mailing list. This -part of my email will never end up in the commit log. Here is where I -can add additional context to the mailing list about my intent, outside -of the context of the commit log. This section was added after `git -format-patch` was run, by editing the patch file in a text editor. - - README.md | 2 +- - 1 file changed, 1 insertion(+), 1 deletion(-) - -diff --git a/README.md b/README.md -index 88f126184c..38da593a60 100644 ---- a/README.md -+++ b/README.md -@@ -3,7 +3,7 @@ - Git - fast, scalable, distributed revision control system - ========================================================= - --Git is a fast, scalable, distributed revision control system with an -+Git is a fast, scalable, and distributed revision control system with an - unusually rich command set that provides both high-level operations - and full access to internals. - --- -2.21.0.392.gf8f6787159e-goog ----- - -[[now-what]] -== My Patch Got Emailed - Now What? - -[[reviewing]] -=== Responding to Reviews - -After a few days, you will hopefully receive a reply to your patchset with some -comments. Woohoo! Now you can get back to work. - -It's good manners to reply to each comment, notifying the reviewer that you have -made the change requested, feel the original is better, or that the comment -inspired you to do something a new way which is superior to both the original -and the suggested change. This way reviewers don't need to inspect your v2 to -figure out whether you implemented their comment or not. - -If you are going to push back on a comment, be polite and explain why you feel -your original is better; be prepared that the reviewer may still disagree with -you, and the rest of the community may weigh in on one side or the other. As -with all code reviews, it's important to keep an open mind to doing something a -different way than you originally planned; other reviewers have a different -perspective on the project than you do, and may be thinking of a valid side -effect which had not occurred to you. It is always okay to ask for clarification -if you aren't sure why a change was suggested, or what the reviewer is asking -you to do. - -Make sure your email client has a plaintext email mode and it is turned on; the -Git list rejects HTML email. Please also follow the mailing list etiquette -outlined in the -https://kernel.googlesource.com/pub/scm/git/git/+/todo/MaintNotes[Maintainer's -Note], which are similar to etiquette rules in most open source communities -surrounding bottom-posting and inline replies. - -When you're making changes to your code, it is cleanest - that is, the resulting -commits are easiest to look at - if you use `git rebase -i` (interactive -rebase). Take a look at this -https://www.oreilly.com/library/view/git-pocket-guide/9781449327507/ch10.html[overview] -from O'Reilly. The general idea is to modify each commit which requires changes; -this way, instead of having a patch A with a mistake, a patch B which was fine -and required no upstream reviews in v1, and a patch C which fixes patch A for -v2, you can just ship a v2 with a correct patch A and correct patch B. This is -changing history, but since it's local history which you haven't shared with -anyone, that is okay for now! (Later, it may not make sense to do this; take a -look at the section below this one for some context.) - -[[after-approval]] -=== After Review Approval - -The Git project has four integration branches: `seen`, `next`, `master`, and -`maint`. Your change will be placed into `seen` fairly early on by the maintainer -while it is still in the review process; from there, when it is ready for wider -testing, it will be merged into `next`. Plenty of early testers use `next` and -may report issues. Eventually, changes in `next` will make it to `master`, -which is typically considered stable. Finally, when a new release is cut, -`maint` is used to base bugfixes onto. As mentioned at the beginning of this -document, you can read `Documents/SubmittingPatches` for some more info about -the use of the various integration branches. - -Back to now: your code has been lauded by the upstream reviewers. It is perfect. -It is ready to be accepted. You don't need to do anything else; the maintainer -will merge your topic branch to `next` and life is good. - -However, if you discover it isn't so perfect after this point, you may need to -take some special steps depending on where you are in the process. - -If the maintainer has announced in the "What's cooking in git.git" email that -your topic is marked for `next` - that is, that they plan to merge it to `next` -but have not yet done so - you should send an email asking the maintainer to -wait a little longer: "I've sent v4 of my series and you marked it for `next`, -but I need to change this and that - please wait for v5 before you merge it." - -If the topic has already been merged to `next`, rather than modifying your -patches with `git rebase -i`, you should make further changes incrementally - -that is, with another commit, based on top of the maintainer's topic branch as -detailed in https://github.com/gitster/git. Your work is still in the same topic -but is now incremental, rather than a wholesale rewrite of the topic branch. - -The topic branches in the maintainer's GitHub are mirrored in GitGitGadget, so -if you're sending your reviews out that way, you should be sure to open your PR -against the appropriate GitGitGadget/Git branch. - -If you're using `git send-email`, you can use it the same way as before, but you -should generate your diffs from `<topic>..<mybranch>` and base your work on -`<topic>` instead of `master`. |