Contributing to PETSc#

As you gain experience in building, using, and debugging with PETSc, you will be able to contribute!

Before contributing code to PETSc, please read PETSc Style and Usage Guide. You may also be interested to read about The Design of PETSc.

PETSc uses Git, GitLab, and its testing system, for its source code management. All new code in PETSc is accepted via merge requests (MRs).

By submitting code, the contributor gives irretrievable consent to the redistribution and/or modification of the contributed source code as described in the PETSc open-source license.

How-Tos#

Some of the source code is documented to provide direct examples/templates for common contributions, adding new implementations for solver components:

Contributing functionality from an external package#

In addition to contributing code directly to the PETSc repository, developers may choose to layer (portions of) their software that lives in its own repository on top of the PETSc API, for example providing their own PCType. An example of this is PFLARE, which is obtained with --download-pflare and registers the PCAIR and PCPFLAREINV preconditioners.

Such a package can also contribute its own PETSc manual pages, generated from the docstrings in its own sources. A package opts in by setting self.providesDocs = 1 and self.docsDirs (the subdirectories that contain the documented sources, for example ['src', 'include']) in its config/BuildSystem/config/packages/<package>.py. When the documentation is built, the sources of each such package are cloned at their pinned self.gitcommit and scanned for the usual PETSc docstring blocks (/*@ @*/, /*MC M*/, /*E E*/), producing manual pages alongside the PETSc ones. See config/BuildSystem/config/packages/PFLARE.py for a prototypical example.

Setting up Git#

We provide some information on common operations here; for more details, see git help, man git, or the Git book.

Install Git if it is not already installed on your machine, then see below to obtain PETSc.
Set up your Git environment to establish your identity.
To stay oriented when working with branches, we encourage configuring git-prompt.
To get tab-completion for Git commands, one can download and then source git-completion.bash.

Obtaining the development version of PETSc#

If you have write access to the PETSc GitLab repository, use git clone git@gitlab.com/petsc/petsc (or use a clone you already have).
Otherwise, Create a fork (your own copy of the PETSc repository).
- You will be asked to “Select a namespace to fork the project”; click the green “Select” button.
- If you already have a clone on your machine of the PETSc repository you would like to reuse
```
$ git remote set-url origin git@gitlab.com:YOURGITLABUSERNAME/petsc.git
```
- otherwise
```
$ git clone git@gitlab.com:YOURGITLABUSERNAME/petsc.git
```

PETSc can now be configured as specified on the Installation page

To update your copy of PETSc

$ git pull

Once updated, you will usually want to rebuild it completely

$ make reconfigure all

This is equivalent to

$ $PETSC_DIR/$PETSC_ARCH/lib/petsc/conf/reconfigure-$PETSC_ARCH.py && make all