mocking.rst: add sections on comptime and linktime redirection

Give examples of using #ifdef and __weak symbols to add a layer of
indirection to function calls.

Also show how we can combine link/compile-time indirection w/ runtime
indirection to have zero-overhead for normal builds, while still
limiting the scope of the changes.

Change-Id: Iaccc1c1708ebbf9cb2662743aaee8fd3ccb38b03
Signed-off-by: Daniel Latypov <>
1 file changed
tree: 2b4d156cc59827a1349aec37dd2e93c4bfb0c751
  1. .gitignore
  4. Makefile
  8. development/
  10. index.rst
  11. mocking.rst
  12. press.rst
  13. statics/
  14. third_party/
  15. usage/

KUnit Documentation

KUnit is a lightweight unit testing and mocking framework for the Linux kernel. These tests are able to be run locally on a developer’s workstation without a VM or special hardware.

KUnit is heavily inspired by JUnit, Python’s unittest.mock, and Googletest/Googlemock for C++. KUnit defines a way to mock out C style classes and functions and create expectations on methods called within the code under test.

This is a repository to host the source for the KUnit documentation.

NOTE: There is an important distinction between KUnit‘s documentation source and it’s documentation site. As a project meant primarily to serve the development of the Linux kernel, a significant portion of our code and documentation reside in the Linux kernel codebase. Consequently, the documentation that does not live in the Linux kernel follows many of the conventions of the Linux kernel. One of these conventions is that we use Sphinx for all of our documentation. Thus, because Sphinx requires documentation to be compiled from its source files, we must have a repository for all the Sphinx source files and a separate repository for all of the generated output files to actually host the site. This is the repository for the source.

Where is the code?

How to build documentation

Documentation can be built by running:

make html

How to update the documentation

Our documentation is hosted at The documentation may be updated by building the documentation as described above, and then:


You can copy the files over without committing and pushing the files with:

./ --no-commit