where to put source files for PGO training programs

[david-fong]

I have a library (a submodule under libs/) that I want to build with profile-guided optimization. To run the instrumented library to collect profile data, I plan to make a setup where I can choose from multiple small-ish training programs which call functions from the library. Where is a good place to put the source code for the training programs?

• They definitely aren't "source code" in the sense of implementing any functionality of the library.
• They aren't tests because they don't have anything to do with checking the correctness of the code.
• They don't seem quite like "extras" since the library is the core part of the project, and the training programs are an essential part of its build process when doing PGO.
• They definitely aren't data, but they are used to produce data (which shouldn't be checking into version control)
• I do have an apps/ directory as discussed as one option in Multiple Executables in Project #30, but PGO training programs just don't feel like "apps" to me. They aren't useful or intended for anything except gathering representative profile data.

I'd like to hear what the authors of this spec think: Would it be "wrong" of me to add a new child directory inside the library's submodule directory just for pgo training program source code?