What is the status of this project?

[bartlettroscoe]

Hello @Jarod42, I was interested to find this project by searching GitHub. I am in the process of open-sourcing a project that scrapes metrics that come out of the clang-tidy readability-function-cognitive-complexity and readability-function-size checks.

But it looks like your project C++ ccccc project provides some more data and uses raw Clang functionality.

Have you been able to keep up with new LLVM releases?

[Jarod42]

It should still work, it uses the 'stable' API.

• Cognitive complexity looks like cyclomatic complexity (probably with different cost for switch case).
• Other simple metrics are simple. I might only expose/collect LOC (line of code) though.

Happy to provide change that might help.

[bartlettroscoe]

@Jarod42, thanks for the response.

The tool ccccc provides some metrics that are not provided by the mentioned clang-tidy checks and the clang-tidy checks provide some metrics that are not provided by ccccc.

I think for ccccc to be a replacement for the clang-tidy metrics-based tool that I am about the release (in a repo to be called cass-clang-metrics ), it would need:

• Updated for more recent versions of LLMV/Clang
• Output to JSON (and then provide separate tools to produce HTML output from filtered JSON?)
• Integrate in the missing metrics produced by the readability-function-cognitive-complexity and readability-function-size checks (might just be copy and paste mostly).
• Consider a more open license like MIT or Apache 2.0 (GPL is very restrictive and many orgs and companies will not touch it.)
• Use full compiler settings from the compile_commands.json file like clang-tidy (to make unambiguous)

The idea that we could have a C++-based tool that we can extend to add more metrics, like class- and module-level fan-in and fan-out, is very attractive.

The other question is if this code could be integrated as a clang-tidy check and extend clang-tidy to be a more general tool that includes gathering and reporting metrics, and not just printing warnings and errors to STDOUT/STDERR.

Anyway, if you are interested, I can post a new issue once our cass-clang-metrics GitHub project gets published and we can discuss options. I am working on a project that is looking to collect a number of metrics for C++ projects and we could potentially do a lot of the work if this makes sense.

[Jarod42]

Updating to more recent version of LLVM/clang should not be an issue.
I have to see which version is available in CI.

I use a template to generate output, so output as json should already be supported (even if I don't use json library).
provided template (for output) are currently csv and html.

Metrics can indeed be added.

I will have to look for license changes, but it might be ok.
Notice than using the tool as application and not as library is possible without breaking the license.

Use full compiler settings from the compile_commands.json file like clang-tidy (to make unambiguous)

Not sure to follow that point, if compile_commands.json is provided as argument, we use that database.
I don't remember if we look for the database for other cases.

Fan-in/Fan-Out are "CallCount"/"CallerCount" as I understand.

The other question is if this code could be integrated as a clang-tidy check

I think clang-tidy doesn't use the stable Clang-API that is used for this project.
I don't know how it is compatible.

[bartlettroscoe]

I use a template to generate output, so output as json should already be supported (even if I don't use json library).

👍

Notice than using the tool as application and not as library is possible without breaking the license.

That is true and that would be sufficient as long as it is only run as an exec.

Use full compiler settings from the compile_commands.json file like clang-tidy (to make unambiguous)

Not sure to follow that point, if compile_commands.json is provided as argument, we use that database.
I don't remember if we look for the database for other cases.

Sorry, I missed that. I was looking at the arguments in https://github.com/Jarod42/ccccc#command-arguments.

Fan-in/Fan-Out are "CallCount"/"CallerCount" as I understand.

Yes, that is handled at the function level by ccccc. I think thinking about similar metrics at the class and module/package level (where modules/package are not well defined in C++ but we there are projects where these are well defined). But from looking at the fields in https://jarod42.github.io/ccccc/, it looks like you could drive those from data at the function level (because you know the parent class, parent namespace, and the file path for every function).

The other question is if this code could be integrated as a clang-tidy check

I think clang-tidy doesn't use the stable Clang-API that is used for this project.

Okay. The question is if the Clang-API being used by ccccc can get everything being counted by the readability-function-cognitive-complexity and readability-function-size checks?

I will take with my project team, but may like to try this out on some of our code bases and compare to the clang-tidy metrics.

What version of llvm would you recommend trying? Would llvm 19.0 likely work? (That is the version being used by one of our key customer projects.)

[Jarod42]

The question is if the Clang-API being used by ccccc can get everything being counted by the readability-function-cognitive-complexity and readability-function-size checks?

function-cognitive-complexity is similar to cyclomatic metric that I compute.
Other metrics are even simple r to collect.

What version of llvm would you recommend trying? Would llvm 19.0 likely work? (That is the version being used by one of our key customer projects.)

Just updated CI to also use llvm-19, and it works too.

[Jarod42]

Just added parameterCount metric.

[bartlettroscoe]

CC: @billhoffman