The tests enable -Werror but generate warnings

[joshvazquez]

The tests enable -Werror here: https://github.com/OpenCyphal/libcanard/blob/master/tests/CMakeLists.txt#L39

The tests also generate warnings, such as unused variable _ here, conversion to long unsigned int from const int may change the sign of the result here. So the tests fail with warnings as errors.

Is this expected? I am using libcanard in CI/CD and would like to keep the tests enabled.

[pavel-kirienko]

This is not expected. The code should be updated to eliminate the warnings you listed. A pull request would be appreciated.

[joshvazquez]

Can't explain this.

Sign conversion warning:

const auto new_size = size_before + static_cast<std::size_t>(ret); // <-- here
enforce((ret < 0) || (new_size == que_.size),
    "Unexpected size change after push");

OK:

const auto num_added = static_cast<std::size_t>(ret);
enforce((ret < 0) || (size_before + num_added == que_.size),
    "Unexpected size change after push");

Compiler magic?

[pavel-kirienko]

Evidently, integer promotion changes the type of the result, which affects the warning.

[joshvazquez]

I'll submit a PR tomorrow on my work account. @joshvazquez-amzn