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Revision as of 16:21, 22 January 2014 by Tim Bird (Talk | contribs) (more splash cleanup)

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Splash is a tool to manage patch series and dependencies between them in git. A 'splash' is a patch series. The 'Splashfile' defines all of our 'splashes' and how they fit together.

Splash is intended to make it easier to work on separate branches of a git tree, merging them and unmerging them at will, in order to keep changes in separate branches but easily integrate them for final work.

Splash keeps track of dependencies and order of merging between branches.

It has similarities to quilt and stacked-git.

Usage help

Simply executing splash.py without parameters or with the parameter 'help' should at least give you usage.

[ FIXTHIS - put usage here. ]

Splash commands

[ FIXTHIS - put list of commands here ]

  • abort - abort the current operation
  • checkout - checkout the specified splash
  • continue - continue the current operation
  • begin - (re)start specified splash
  • fetch - fetch tree up until specified splash
  • start - ??
  • status - display all splashes
  • log - shwo current log-graph up to base
  • merge - merge another splash onto this one (or this one onto another?)
  • unmerge - remove another splash from this one (or this one from another?)
  • rebuild - rebuild tree
  • sync - rebuild tree and push all dependent splashes to remote
  • help. -h or --help - print usage and exit
  • -l or --list - list splashes and exit
  • -b or --base - specify base splash
  • -v or --verbose - be verbose

Splash setup

Splash includes the splash.py program and a configuration file called 'Splashfile'.

The configuration file contains descriptions of the 'splashes' in a particular repository. To use splash, symlink the Splashfile to the working kernel directory. Put the splash.py program on your path (usually somewhere like ~/bin.

In order to use splash, you have to first fetch the splashes.

$ splash.py fetch <splash_name>

Splash workflow

As a general rule, working with splash works like so:

$ splash.py fetch <splash_name>
  # edit Splashfile to add splash 'my-feature'
$ splash.py start my-feature
  # make / add commits
$ git update-ref refs/splash/my-feature HEAD
$ splash.py push my-feature

At any point you can also do:

$ splash.py merge rhine/int
  # test
$ splash.py unmerge rhine/int

If you change dependencies in the Splashfile, such as adding 'my-feature' to the rhine/int deps, you'll need to execute:

$ splash rebuild rhine/int

Recovering from errors

Splash has its own batch parser, similar to the one in a git interactive rebase. Previous to splash, the developers used to use 'git interactive rebase', but it is slow, and you can't batch rebases this way.

If a command fails in any way (other than argument parsing), you can recover by executing:

$ splash.py abort

or, to try the operation again, do:

$ splash.py continue

In general, Sony keeps topic branches in git under .git/refs/topics/<developer_name>/foo According to many tools these aren't valid refs because they aren't under refs/heads/ or refs/tags/.

Retrieving a topic branch and making a local branch

You can download and have all the splashes as local refs in one of the following ways:

  • $ splash.py fetch # or fetch-all or fetchall; fetches all splashes
  • $ splash.py fetch rhine/int # for all splashes rhine/int depends on
  • $ git fetch origin $(for ref in `sed -n '/^ref/x;s/ref\s*=\s*//p' Splashfile`; do
        echo "$ref:refs/heads/${ref:12}"; done)  # poor man's splash

If you do it with splash, they won't be branches, but instead refs in refs/splash/<splash-name>. If you want to turn these into branches, try:

$ for splash in `find .git/refs/splash/ -type f`; do
     git update-ref refs/heads/splash/${splash:17} ${splash:5}; done

but keep in mind that these branches will need to be updated every time you change anything in splash. You can also make the ref a symlink instead to fix this, but I'll leave that as an exercise for the reader.

This replaced my retrieval of a topic branch:

$ git fetch origin refs/topics/<dev_name>/<splash_name>
$ git checkout -b <local_branch_name> FETCH_HEAD

WIP documentation


  • Q: what is the 'splash.remote' needed by splash?
  • Q:


Splash can not show help (-h) in some situations

Doing 'splash.py -h' in a repostiroy without a splash.remote results in:

No upstream specified
Please run `git config --local --add splash.remote <remote>`

If you run this outside of a git directory, you get the following:

$ splash
fatal: Not a git repository (or any parent up to mount point /home)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
Traceback (most recent call last):
  File "/home/CORPUSERS/10102229/bin/splash", line 436, in <module>
    gitconfig = GitConfig()
  File "/home/CORPUSERS/10102229/bin/splash", line 71, in __init__
    raise subprocess.CalledProcessError(repo.returncode, cmd, output=out)
subprocess.CalledProcessError: Command '['git', 'rev-parse', '--git-dir']' returned non-zero exit status 128