[llvm] [llvm]Add a simple Telemetry framework (PR #102323)

[James Henderson via llvm-commits]

https://github.com/jh7370 commented:

As noted elsewhere, please redo all your variable and function names to conform with the coding standards. It's surprisingly distracting having them wrong! Also, please reflow your comments to properly use the 80 character width, as it makes it a little harder to read when they are broken at somewhat arbitrary lengths.

To help reviewers, could you add some comments (potentially doxygen style) to the classes that you've added that describe their intended purpose, along with possibly a top-level comment highlighting the overall structure and how a tool might use this telemetry code - I'm aware that some of this is in the RFC, but ultimately people won't want to have to refer to an old RFC thread to discuss this. It might be even best to put the overall design and usage description under the llvm/docs folder.

I think you need at least one concrete implementation that can be used to write to a raw_ostream instance, which can be used for unit testing, and which helps to illustrate the interface.

https://github.com/llvm/llvm-project/pull/102323