cpytest 0.1.0

Python's pytest for C code

sudo apt install gcovr
sudo apt insall lcov

virtualenv .venv
source .venv/bin/activate
pip install -U pip
pip install -r requirements.txt

./clean

python3 test/build_example.py
pytest test/test_example.py

lcov --capture --directory src --base-directory test/build --output-file coverage.info --rc lcov_branch_coverage=1 --no-external
genhtml coverage.info --output-directory coverage_report --rc genhtml_branch_coverage=1

# for gcovr to work, we'd need to change the cffi compilation location to be on the project root folder. otherwise
# it can't follow the relative paths, which are pointing from test/build
gcovr --root . --html --html-details -o coverage.html

cPyGen

# preprocess
gcc -E -Iinc src/example.c -o test/build/example.i
# generate
python3 cpygen.py

The cpygen.py is an experiment using pycparser. In order to parse GCC specific extensions, pycparserext is used.

pycparser is supposed to run on preprocessed C code.

Important to install in this order, because of version incompatibilities. pycparserext==2021.1 depends on pycparser==2.20, but we need pycparser==2.21. The corresponding pip install error can be ignored.

Unfortunately, the pycparsext project is quite incomplete. __attribue__(()) directives on structs are not supported. As an alternative for such cases, the #pragma pack needs to be used so that we're able to process packed structs. Processing packed structs is important, because we have to generate specific python code for them.

Dependencies

pip install pycparserext==2021.1
pip install pycparser==2.21

Running (new)

./clean.sh
py cpytest/cpygen.py
py example/test/build_example.py
pytest example/test/test_example.py
lcov --capture --directory example/src --base-directory example/test/builds --output-file coverage.info --rc lcov_branch_coverage=1 --no-external
genhtml coverage.info --output-directory coverage_report --rc genhtml_branch_coverage=1

Running (manual steps) (old)

./clean.sh
mkdir example/test/build
# preprocess source file
gcc -E -Iexample/inc example/src/example.c -o example/test/build/example.i
# generate cffi python stubs into "out.c/out.h"
python3 cpytest/cpygen.py
# manual step: update "test/build_example.py": copy code from "out.c" and "out.h" into the test file
# compile the source file with generated stubs, and create the cffi python module
python3 test/build_example.py
# run the python unit tests against the compiled source
pytest test/test_example.py

Run QA

pytest test/test_cpygen.py
flake8 --max-line-length 120 cpytest/cpygen.py test/test_cpygen.py example/test/build_example.py
pylint --max-line-length 120 cpytest/cpygen.py

Docker

cd docker
docker-compose up --build test-example-project

docker-compose up -d shell
docker-compose exec shell bash

docker-compose down