CMake/Git/Develop

This page documents how to develop CMake through Git. See our table of contents for more information.

Git is an extremely powerful version control tool that supports many different "workflows" for indivudal development and collaboration. Here we document procedures used by the CMake development community. In the interest of simplicity and brevity we do not provide an explanation of why we use this approach. Furthermore, this is not a Git tutorial. Please see our Git resource links for third-party documentation, such as the ProGit Book.

Setup

Before you begin, perform initial setup:

1. Register Git push access.
2. Follow the download instructions to create a local CMake clone:
$ git clone git://cmake.org/cmake.git	Connection refused?
3. Follow the local hook setup instructions to get local commit hooks:
$ cd .git/hooks $ git init $ git pull .. remotes/origin/hooks $ cd ../..	Pro Git: Setup

Workflow

CMake development uses a branchy workflow based on topic branches. Our collaboration workflow consists of three main steps:

1. Local Development

Update

Create a Topic

2. Testing and Review

Share a Topic

Merge a Topic for Testing

Extend a Topic

3. Integration by Maintainers

Merge a Topic for Inclusion

Delete a Topic

Update

Update your local master branch:
$ git checkout master $ git pull	git help checkout git help pull

Create a Topic

All new work must be committed on topic branches. Name topics like you might name functions: concise but precise. A reader should have a general idea of the feature or fix to be developed given just the branch name.

To start a new topic branch:
$ git fetch origin $ git checkout -b my-topic origin/master (If you are fixing a bug in the latest release then substitute origin/release for origin/master.)	git help fetch git help checkout Pro Git: Basic Branching
Edit files and create commits (repeat as needed):
$ edit file1 file2 file3 $ git add file1 file2 file3 $ git commit	git help add git help commit Pro Git: Recording Changes

Share a Topic

When a topic is ready for testing and review by others, share it by pushing it to the topic stage. Be sure you have registered for Git push access.

Checkout the topic if it is not your current branch:
$ git checkout my-topic	git help checkout
Check what commits will be pushed to the topic stage:
$ git log origin/master..	git help log
Push commits in your topic branch to the topic stage:
$ git push stage HEAD	git help push

The topic is now published on the CMake Topic Stage and may be (optionally) reviewed by others.

Merge a Topic for Testing

When your topic is ready, merge it to the CMake next branch for testing.

Ask the topic stage to automatically merge the topic to next:
$ ssh git@cmake.org stage cmake merge -b next my-topic (If the merge conflicts follow the printed instructions to resolve them.)	Topic-to-Topic Conflict Resolution

The topic is now integrated into CMake's next branch and will be tested by dashboard builds.

Extend a Topic

If your topic runs cleanly after a night of dashboard builds, it is ready for the next step. Otherwise, extend the topic with additional commits to fix the problems.

Checkout the topic if it is not your current branch:
$ git checkout my-topic	git help checkout
Edit files and create commits (repeat as needed):
$ edit file1 file2 file3 $ git add file1 file2 file3 $ git commit	git help add git help commit Pro Git: Recording Changes
Return to the earlier step to share the extended topic.

Merge a Topic for Inclusion

Only core maintainers have access to merge a topic to master. They meet weekly to evaluate topics in next based on dashboard results and manual review. If your topic is accepted it will be merged to master for permanent inclusion after which you may delete it. Otherwise the maintainers will contact you with feedback. Respond by returning to the above step to address their concerns.

Delete a Topic

After a topic has been merged upstream, delete your local branch for the topic.

Checkout and update the master branch:
$ git checkout master $ git pull	git help checkout git help pull
Delete the local topic branch:
$ git branch -d my-topic	git help branch
The branch -d command works only when the topic branch has been correctly merged. Use -D instead of -d to force the deletion of an unmerged topic branch (warning - you could lose commits).