Generate compile_commands.json from msbuild via command line -- no cmake

I'm looking for a way to integrate clang-tidy into a CI workflow, but the build system being used is MSBuild with dependencies managed by vcpkg in manisfest mode.

Is there some advanced command line that I can pass MSBuild (or some other tool that understands MSBuild process completely) to be able to generate compile_commands.json?

I'm sure I'm not the first one to try that, I've seen a couple of cases of success using SourceTrail and ClangPowerTools, but it has been specially painful in my case because the alternatives cannot detect the include paths exposed by vcpkg.

It turns out that msbuild has a builtin target for clang-tidy since Visual Studio started to support that linter.

To invoke it one can run : msbuild /t:ClangTidy ....

Unfortunately, very few command line options are exposed from the clang-tidy integration to msbuild CLI: the list of checks, the header-filter, additional compiler options, a flag for warnings in system headers and the tool path.

If one wants to export the fixes file generated by clang-tidy, which was my case, it needs to do some extra work.

I achieved my goal by adding one Directory.Build.props file in the project folder which overrides the path to the original clang-tidy.exe with a batch script (.bat), which does some preparation steps and forwards the msbuild target command line to a python script which can invoke clang-tidy with its full command line capabilities.

The props file:

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    
    <ClangTidyToolPath>$(where_I_saved_the_bat_file)\</ClangTidyToolPath>
    <ClangTidyToolExe>msbuild-clang-tidy-runner.bat</ClangTidyToolExe>
  </PropertyGroup>
</Project>

The batch file:

SET PYTHONPATH=...
REM and maybe other stuff
python3 -m my_custom_clang_tidy_runner  %*

Interestingly the batch file was the only way other than a real executable file that I could place in the Directory.Build.props that wouldn't result in msbuild compilation error. I tried python and powershell scripts and none were accepted as a suitable clang-tidy executable file. I experimented creating a C++ program which does the same as my Python script and it worked as expected as well.

So, to summarize, the recipe is:

1. Create the Directory.Build.props file in the root folder of the project you want to lint overriding the clang-tidy path.
2. A custom .exe or .bat file to replace clang-tidy capable of forwarding the command line options passed by msbuild together with any customisation you wish.
3. Invoke msbuild /t:ClangTidy ... and Bob's your uncle!