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diff --git a/third_party/git/Documentation/gitsubmodules.txt b/third_party/git/Documentation/gitsubmodules.txt deleted file mode 100644 index 891c8da4fdf7..000000000000 --- a/third_party/git/Documentation/gitsubmodules.txt +++ /dev/null @@ -1,287 +0,0 @@ -gitsubmodules(7) -================ - -NAME ----- -gitsubmodules - Mounting one repository inside another - -SYNOPSIS --------- - .gitmodules, $GIT_DIR/config ------------------- -git submodule -git <command> --recurse-submodules ------------------- - -DESCRIPTION ------------ - -A submodule is a repository embedded inside another repository. -The submodule has its own history; the repository it is embedded -in is called a superproject. - -On the filesystem, a submodule usually (but not always - see FORMS below) -consists of (i) a Git directory located under the `$GIT_DIR/modules/` -directory of its superproject, (ii) a working directory inside the -superproject's working directory, and a `.git` file at the root of -the submodule's working directory pointing to (i). - -Assuming the submodule has a Git directory at `$GIT_DIR/modules/foo/` -and a working directory at `path/to/bar/`, the superproject tracks the -submodule via a `gitlink` entry in the tree at `path/to/bar` and an entry -in its `.gitmodules` file (see linkgit:gitmodules[5]) of the form -`submodule.foo.path = path/to/bar`. - -The `gitlink` entry contains the object name of the commit that the -superproject expects the submodule's working directory to be at. - -The section `submodule.foo.*` in the `.gitmodules` file gives additional -hints to Git's porcelain layer. For example, the `submodule.foo.url` -setting specifies where to obtain the submodule. - -Submodules can be used for at least two different use cases: - -1. Using another project while maintaining independent history. - Submodules allow you to contain the working tree of another project - within your own working tree while keeping the history of both - projects separate. Also, since submodules are fixed to an arbitrary - version, the other project can be independently developed without - affecting the superproject, allowing the superproject project to - fix itself to new versions only when desired. - -2. Splitting a (logically single) project into multiple - repositories and tying them back together. This can be used to - overcome current limitations of Git's implementation to have - finer grained access: - - * Size of the Git repository: - In its current form Git scales up poorly for large repositories containing - content that is not compressed by delta computation between trees. - For example, you can use submodules to hold large binary assets - and these repositories can be shallowly cloned such that you do not - have a large history locally. - * Transfer size: - In its current form Git requires the whole working tree present. It - does not allow partial trees to be transferred in fetch or clone. - If the project you work on consists of multiple repositories tied - together as submodules in a superproject, you can avoid fetching the - working trees of the repositories you are not interested in. - * Access control: - By restricting user access to submodules, this can be used to implement - read/write policies for different users. - -The configuration of submodules -------------------------------- - -Submodule operations can be configured using the following mechanisms -(from highest to lowest precedence): - - * The command line for those commands that support taking submodules - as part of their pathspecs. Most commands have a boolean flag - `--recurse-submodules` which specify whether to recurse into submodules. - Examples are `grep` and `checkout`. - Some commands take enums, such as `fetch` and `push`, where you can - specify how submodules are affected. - - * The configuration inside the submodule. This includes `$GIT_DIR/config` - in the submodule, but also settings in the tree such as a `.gitattributes` - or `.gitignore` files that specify behavior of commands inside the - submodule. -+ -For example an effect from the submodule's `.gitignore` file -would be observed when you run `git status --ignore-submodules=none` in -the superproject. This collects information from the submodule's working -directory by running `status` in the submodule while paying attention -to the `.gitignore` file of the submodule. -+ -The submodule's `$GIT_DIR/config` file would come into play when running -`git push --recurse-submodules=check` in the superproject, as this would -check if the submodule has any changes not published to any remote. The -remotes are configured in the submodule as usual in the `$GIT_DIR/config` -file. - - * The configuration file `$GIT_DIR/config` in the superproject. - Git only recurses into active submodules (see "ACTIVE SUBMODULES" - section below). -+ -If the submodule is not yet initialized, then the configuration -inside the submodule does not exist yet, so where to -obtain the submodule from is configured here for example. - - * The `.gitmodules` file inside the superproject. A project usually - uses this file to suggest defaults for the upstream collection - of repositories for the mapping that is required between a - submodule's name and its path. -+ -This file mainly serves as the mapping between the name and path of submodules -in the superproject, such that the submodule's Git directory can be -located. -+ -If the submodule has never been initialized, this is the only place -where submodule configuration is found. It serves as the last fallback -to specify where to obtain the submodule from. - -FORMS ------ - -Submodules can take the following forms: - - * The basic form described in DESCRIPTION with a Git directory, -a working directory, a `gitlink`, and a `.gitmodules` entry. - - * "Old-form" submodule: A working directory with an embedded -`.git` directory, and the tracking `gitlink` and `.gitmodules` entry in -the superproject. This is typically found in repositories generated -using older versions of Git. -+ -It is possible to construct these old form repositories manually. -+ -When deinitialized or deleted (see below), the submodule's Git -directory is automatically moved to `$GIT_DIR/modules/<name>/` -of the superproject. - - * Deinitialized submodule: A `gitlink`, and a `.gitmodules` entry, -but no submodule working directory. The submodule's Git directory -may be there as after deinitializing the Git directory is kept around. -The directory which is supposed to be the working directory is empty instead. -+ -A submodule can be deinitialized by running `git submodule deinit`. -Besides emptying the working directory, this command only modifies -the superproject's `$GIT_DIR/config` file, so the superproject's history -is not affected. This can be undone using `git submodule init`. - - * Deleted submodule: A submodule can be deleted by running -`git rm <submodule path> && git commit`. This can be undone -using `git revert`. -+ -The deletion removes the superproject's tracking data, which are -both the `gitlink` entry and the section in the `.gitmodules` file. -The submodule's working directory is removed from the file -system, but the Git directory is kept around as it to make it -possible to checkout past commits without requiring fetching -from another repository. -+ -To completely remove a submodule, manually delete -`$GIT_DIR/modules/<name>/`. - -ACTIVE SUBMODULES ------------------ - -A submodule is considered active, - - 1. if `submodule.<name>.active` is set to `true` -+ -or - - 2. if the submodule's path matches the pathspec in `submodule.active` -+ -or - - 3. if `submodule.<name>.url` is set. - -and these are evaluated in this order. - -For example: - - [submodule "foo"] - active = false - url = https://example.org/foo - [submodule "bar"] - active = true - url = https://example.org/bar - [submodule "baz"] - url = https://example.org/baz - -In the above config only the submodule 'bar' and 'baz' are active, -'bar' due to (1) and 'baz' due to (3). 'foo' is inactive because -(1) takes precedence over (3) - -Note that (3) is a historical artefact and will be ignored if the -(1) and (2) specify that the submodule is not active. In other words, -if we have a `submodule.<name>.active` set to `false` or if the -submodule's path is excluded in the pathspec in `submodule.active`, the -url doesn't matter whether it is present or not. This is illustrated in -the example that follows. - - [submodule "foo"] - active = true - url = https://example.org/foo - [submodule "bar"] - url = https://example.org/bar - [submodule "baz"] - url = https://example.org/baz - [submodule "bob"] - ignore = true - [submodule] - active = b* - active = :(exclude) baz - -In here all submodules except 'baz' (foo, bar, bob) are active. -'foo' due to its own active flag and all the others due to the -submodule active pathspec, which specifies that any submodule -starting with 'b' except 'baz' are also active, regardless of the -presence of the .url field. - -Workflow for a third party library ----------------------------------- - - # Add a submodule - git submodule add <url> <path> - - # Occasionally update the submodule to a new version: - git -C <path> checkout <new version> - git add <path> - git commit -m "update submodule to new version" - - # See the list of submodules in a superproject - git submodule status - - # See FORMS on removing submodules - - -Workflow for an artificially split repo --------------------------------------- - - # Enable recursion for relevant commands, such that - # regular commands recurse into submodules by default - git config --global submodule.recurse true - - # Unlike most other commands below, clone still needs - # its own recurse flag: - git clone --recurse <URL> <directory> - cd <directory> - - # Get to know the code: - git grep foo - git ls-files --recurse-submodules - -[NOTE] -`git ls-files` also requires its own `--recurse-submodules` flag. - - # Get new code - git fetch - git pull --rebase - - # Change worktree - git checkout - git reset - -Implementation details ----------------------- - -When cloning or pulling a repository containing submodules the submodules -will not be checked out by default; you can instruct `clone` to recurse -into submodules. The `init` and `update` subcommands of `git submodule` -will maintain submodules checked out and at an appropriate revision in -your working tree. Alternatively you can set `submodule.recurse` to have -`checkout` recursing into submodules (note that `submodule.recurse` also -affects other Git commands, see linkgit:git-config[1] for a complete list). - - -SEE ALSO --------- -linkgit:git-submodule[1], linkgit:gitmodules[5]. - -GIT ---- -Part of the linkgit:git[1] suite |