Updating Third Party Projects#
When updating a third party project, any changes to the imported project
itself (e.g., the
zlib/vtkzlib directory for zlib), should go through the
update.sh framework. This framework ensures that all patches to the third
party projects are tracked externally and available for (preferably) upstream
or other projects also embedding the library.
The Imported Third Party Projects document lists all projects grouped by import method:
Any updates to projects imported through the
copy method should first be converted
over to the
Updating a Project Upstream#
Ideally, any code changes to third party code should first be submitted to the upstream project using whatever workflow they prefer or require. Once that is done, the changes can next be brought into VTK.
Updating the Import#
Examine the project’s
update.sh script and note the value of the
If it’s referring to anything other than Kitware’s GitLab, then skip to the next section.
Otherwise, you first need to bring in the upstream changes into the
To do that, first fork and clone the repository named in the
Then use git commands to bring in a copy of the upstream changes.
Here’s an example of updating the
twisted project from tag 17.1.0 to 17.5.0:
$ cd twisted/
$ git checkout for/vtk
$ git fetch origin
$ git rebase --onto twisted-17.5.0 twisted-17.1.0
$ git push
When deciding what to rebase, you should generally use the first commit in the current history that isn’t upstream.
Updating a Project into VTK#
Bringing changes into VTK involves first deciding what to bring in. That is specified in the
update.sh script under the
tag= field. Usually this is a
for/vtk branch, but may
master, or a tag, or any other Git reference.
update.sh needs to be edited (the usual case), create a branch in the usual way
and commit just those changes.
Next, run the
update.sh script as below. This will update the local copy of the project to
the version specified within.
$ cd vtk/ThirdParty/zlib
$ git checkout -b update_zlib_YYYY_MM_DD
Appending the date to the branch name is not necessary, it just prevents any conflict in the event of you doing this procedure multiple times and inadvertently using the same branch name.
(All this requires a Git 2.5 or higher due the
worktree tool being used to
simplify the availability of the commits to the main checkout.)
Make sure to update the
CMakeLists.txt to reflect
the changes made to the project.
Now you can review the change and make a merge request from the branch as normal.
Porting a Project#
When converting a project, if there are any local patches, a project should be created on Kitware’s GitLab to track it (requests may be filed on the repo-requests repository). If the upstream project does not use Git, it should be imported into Git (there may be existing conversions available on Github already). The project’s description should indicate where the source repository lives.
Once a mirror of the project is created, a branch named
for/foo should be
created where patches for the
foo project will be applied (i.e.,
for VTK’s patches to the project). Usually, changes to the build system, the
source code for mangling, the addition of
.gitattributes files, and other
changes belong here. Functional changes should be submitted upstream (but may
still be tracked so that they may be used).
For mangling documentation, some guidelines are available.
The basic steps to import a project
twisted based on the tag
twisted-17.1.0 looks like this:
$ git clone https://github.com/twisted/twisted.git
$ cd twisted/
$ git remote add kitware firstname.lastname@example.org:third-party/twisted.git
$ git push -u kitware
$ git push -u kitware --tags
$ git checkout twisted-17.1.0
$ git checkout -b for/vtk
$ git push --set-upstream kitware for/vtk
Making the initial import involves filling out the project’s
script in its directory. The update-common.sh script
describes what is necessary, but in a nutshell, it is basically metadata such
as the name of the project and where it goes in the importing project.
The most important bit is the
extract_source function which should subset
the repository. If all that needs to be done is to extract the files given in
paths variable (described in the
update-common.sh script), the
git_archive function may be used if the
git archive tool generates a
update.sh is executable before commit. On Unix, run:
$ chmod u+x update.sh && git add -u update.sh
On Windows, run:
$ git update-index --chmod=+x update.sh
Also add an entry to Imported Third Party Projects for the project, and
module.cmake as appropriate.
The basic process involves a second branch where the third party project’s
changes are tracked. This branch has a commit for each time it has been
updated and is stripped to only contain the relevant parts (no unit tests,
documentation, etc.). This branch is then merged into the main branch as a
subdirectory using the
subtree merge strategy.
Initial conversions will require a manual push by the maintainers since the conversion involves a root commit which is not allowed under normal circumstances. Please post a message on the VTK Discourse forum asking for assistance if necessary.