Clang-Tidy doesn't find standard C++ modules, despite providing compilation database and prebuilt modules path

[ben.boeckel]

@lecris

Where is the “response files”?

They’re stuffed under CMakeFiles/target.dir/source.cxx.o.modmap. The compile_commands.json should have it there, but there is an issue for that.

@lecris

Wouldn’t that affect normal clang-tidy run as well (external clang-tidy not linked to cmake targets).

Yes.

@lecris

So what’s the plan for this one? would cmake create a new standard of modules_commands.json, or are there already standards that have just not yet been implemented in cmake? Is there a blocking issue somewhere?

I expect there to be a per-target modules_commands.json that gets generated during the build, yes. It cannot be for the entire build because then running part of it will not update the overall file. A mechanism to merge all files for complete builds (though EXCLUDE_FROM_ALL throws a wrench in here) could be provided though that works for the all target at least.