Testing Yosys

Running the included test suite

The Yosys source comes with a test suite to avoid regressions and keep everything working as expected. Tests can be run by building the test target from the root Yosys directory. By default, this runs vanilla and unit tests.

cmake -B build .
cmake --build build --target test --parallel $(nproc)

Vanilla tests

These make up the majority of our testing coverage. They can be run with the test-vanilla CMake target. Usually their structure looks something like this: you write a .ys file that gets automatically run, which runs a frontend like read_verilog or read_rtlil with a relative path or a heredoc, then runs some commands including the command under test, and then uses Selections with -assert-count. Usually it’s unnecessary to “register” the test anywhere as if it’s being added to an existing directory, depending on how the run-test.sh in that directory works.

Unit tests

Running the unit tests requires the following additional packages:

sudo apt-get install libgtest-dev

No additional requirements.

Unit tests can be run with the test-unit CMake target.

Functional tests

Testing functional backends (see Writing a new backend using FunctionalIR) has a few requirements in addition to those listed in Build prerequisites:

sudo apt-get install racket
raco pkg install rosette
pip install pytest-xdist pytest-xdist-gnumake
brew install racket
raco pkg install rosette
pip install pytest-xdist pytest-xdist-gnumake

If you don’t have one of the CAD suite(s) installed, you should also install Z3 following their instructions.

Docs tests

There are some additional tests for checking examples included in the documentation, which can be run with the test-docs CMake target. This also includes checking some macro commands to ensure that descriptions of them are kept up to date, and is mostly intended for CI.

Automatic testing

The Yosys Git repo has automatic testing of builds and running of the included test suite on both Ubuntu and macOS, as well as across range of compiler versions. For up to date information, including OS versions, refer to the git actions page.