On Sun, Jan 14, 2018 at 9:37 AM, Kaartic Sivaraam <kaartic.sivaraam@xxxxxxxxx> wrote: > * Only mention porcelain commands in examples > > * Split a sentence for better readability > > * Add missing apostrophes > > * Clearly specify the advantages of using submodules > > * Avoid abbreviations > > * Use "Git" consistently > > * Improve readability of certain lines > > * Clarify when a submodule is considered active > > Helped-by: Eric Sunshine <sunshine@xxxxxxxxxxxxxx> > Helped-by: Stefan Beller <sbeller@xxxxxxxxxx> > Signed-off-by: Kaartic Sivaraam <kaartic.sivaraam@xxxxxxxxx> > --- Thanks, Stefan > Documentation/gitsubmodules.txt | 100 +++++++++++++++++++++++++++++++--------- > 1 file changed, 79 insertions(+), 21 deletions(-) > > diff --git a/Documentation/gitsubmodules.txt b/Documentation/gitsubmodules.txt > index 46cf120f6..4d6c17782 100644 > --- a/Documentation/gitsubmodules.txt > +++ b/Documentation/gitsubmodules.txt > @@ -36,8 +36,8 @@ 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 Gits porcelain layer such as where to obtain the submodule via > -the `submodule.foo.url` setting. > +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: > > @@ -51,18 +51,21 @@ Submodules can be used for at least two different use cases: > > 2. Splitting a (logically single) project into multiple > repositories and tying them back together. This can be used to > - overcome current limitations of Gits implementation to have > + overcome current limitations of Git's implementation to have > finer grained access: > > - * Size of the git repository: > + * 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. > - However you can also use submodules to e.g. hold large binary assets > - and these repositories are then shallowly cloned such that you do not > + 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. > @@ -73,9 +76,10 @@ 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 submodule specs. > - Most commands have a boolean flag '--recurse-submodules' whether to > - recurse into submodules. Examples are `ls-files` or `checkout`. > + * 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. > > @@ -87,8 +91,8 @@ Submodule operations can be configured using the following mechanisms > 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, which does pay attention > -to its `.gitignore` file. > +directory by running `status` in the submodule while paying attention > +to the `.gitignore` file of the submodule. > + > The submodule's `$GIT_DIR/config` file would come into play when running > `git push --recurse-submodules=check` in the superproject, as this would > @@ -97,20 +101,20 @@ remotes are configured in the submodule as usual in the `$GIT_DIR/config` > file. > > * The configuration file `$GIT_DIR/config` in the superproject. > - Typical configuration at this place is controlling if a submodule > - is recursed into at all via the `active` flag for example. > + Git only recurses into active submodules (see "ACTIVE SUBMODULES" > + section below). > + > If the submodule is not yet initialized, then the configuration > -inside the submodule does not exist yet, so configuration where to > +inside the submodule does not exist yet, so where to > obtain the submodule from is configured here for example. > > - * the `.gitmodules` file inside the superproject. Additionally to the > - required mapping between submodule's name and path, a project usually > + * The `.gitmodules` file inside the superproject. A project usually > uses this file to suggest defaults for the upstream collection > - of repositories. > + of repositories for the mapping that is required between a > + submodule's name and its path. > + > -This file mainly serves as the mapping between name and path in > -the superproject, such that the submodule's git directory can be > +This file mainly serves as the mapping between the name and path of submodules > +in the superproject, such that the submodule's Git directory can be > located. > + > If the submodule has never been initialized, this is the only place > @@ -137,8 +141,8 @@ directory is automatically moved to `$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. > +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`. > @@ -160,6 +164,60 @@ from another repository. > To completely remove a submodule, manually delete > `$GIT_DIR/modules/<name>/`. > > +ACTIVE SUBMODULES > +----------------- > + > +A submodule is considered active, > + > + (a) if `submodule.<name>.active` is set to `true` > + or > + (b) if the submodule's path matches the pathspec in `submodule.active` > + or > + (c) 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 (a) and 'baz' due to (c). 'foo' is inactive because > +(a) takes precedence over (c) > + > +Note that (c) is a historical artefact and will be ignored if the > +(a) and (b) specify that the submodule is not active. In other words, > +if we have an `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 > ---------------------------------- > > -- > 2.16.0.rc1.281.g969645f98 >
