From: "James H Cownie" <james.h.cownie@intel.com>
To: openmp-dev@dcs-maillist2.engr.illinois.edu
Cc: "Hal Finkel (hfinkel@anl.gov)" <hfinkel@anl.gov>
Sent: Wednesday, October 8, 2014 2:51:44 AM
Subject: Splitting version changes
Over on the commits list Hal pointed out that
> These things, and the license headers, should really be committed
> separately.
> There are several different ways to separate a patch file into
> separate commits
> (and at least several of us here who have experience doing surgery
> on patches).
> Feel free to ask for advice (might as well do it on the dev list:
> it is a common problem), and you shall receive it.
So, Hal, please enlighten us.
I'll preface this by saying that there may yet be better ways, but here's what I've used...
First, I'd be remiss were I to neglect to mention that emacs has a really-nice patch-editing mode. Here's some documentation:
https://www.gnu.org/software/emacs/manual/html_node/emacs/Diff-Mode.html
and if you really need to do some non-trivial surgery directly on a patch file, I've not found a better alternative (I normally use vim, but this is the one thing for which I use emacs). To use this for splitting, you'd make several copies of the patch file and, in each, delete the non-relevant parts from each.
Next, I'll strongly recommend that you use 'git svn' to manage your interaction with the upstream subversion repository instead of using svn directly. I should mention that, since the OpenMP repository does not have much history, you can just do a full clone:
git svn clone https://llvm.org/svn/llvm-project/openmp/trunk openmp-trunk
if you try this with LLVM or Clang, it will take a *long* time because it tries to replay the remote repository one commit at a time. For this, add -r HEAD so that it will just start at the latest commit. There's lots of information out there on using git svn, including:
http://llvm.org/docs/GettingStarted.html#for-developers-to-work-with-git-svn
http://git-scm.com/book/en/Git-and-Other-Systems-Git-and-Subversion
To the topic at hand, once you're using git locally, you can read "Splitting up commits the easy way" (http://cbx33.github.io/gitt/afterhours5-1.html) which talks about how to use git's interactive staging feature to split up a large patch file and commit it in separate pieces. This can be done both using command-line tools and also using 'git gui' if you'd prefer the GUI-based interface.
If you'd like more information and/or help on any of these, please feel free to ask.
Thanks again,
Hal
