Unclear how to use ament_clang_tidy about ament_lint

[mm318]

The action is on me to produce a pull request. I will try to get that done by the end of next week.

[JShep1]

ament_clang_tidy is essentially a wrapped call to clang-tidy so it may be necessary to create a compile_commands.json file in order for extraneous header files to be found and other corrections to be made (see also here).

[mm318]

My current understanding is that even if we do have compile_commands.json present, ament_clang_tidy does not pass the relevant -p option to the underlying clang-tidy.

@dirk-thomas and @JShep1, I propose we enhance ament_clang_tidy --fix-errors to do the following:

1. Run colcon configure --cmake-args -DCMAKE_EXPORT_COMPILE_COMMANDS=ON to run the CMake configuration step for generating the relevant compile_commands.json file. (If the configure verb doesn't exist in colcon, we should add it. It will perform a subset of what build currently does.)
2. ament_clang_tidy --fix-errors will search subdirectories for compile_commands.json and make calls to run-clang-tidy -fix -p <path_to_db>¹

¹: Why call run-clang-tidy instead of clang-tidy? The clang project provided this script to dedupe fixes to header files, which could be analyzed and otherwise "fixed" multiple times per project.

[jacobperron]

@mm318 I'd discourage using colcon as part of any ament functionality since ament packages should not have to depend on or have knowledge of colcon. Can the compile_commands.json be generated independently for your project? We can likely still improve ament_clang_tidy to accept the compilation database file.

[mm318]

@mm318 I'd discourage using colcon as part of any ament functionality since ament packages should not have to depend on or have knowledge of colcon.

Okay, that's reasonable.

We can likely still improve ament_clang_tidy to accept the compilation database file.

I already have a script that makes clang-tidy use a compilation database file to find lint issues correctly (but it can't fix issues). I can contribute that to ament_clang_tidy.

To use this script currently, I am indeed independently generating the compile_commands.json file for my project through colcon build before running the script.

[dirk-thomas]

@mm318 What is the status of this ticket?

[mm318]

The pull request at #213 is ready for review, @JShep1, @jacobperron, and @dirk-thomas.

[ivanpauno]

Connected PR has been merged, closing