[clang-tools-extra] [clang-tidy] support query based custom check (PR #131804)

[Carlos Galvez via cfe-commits]

carlosgalvezp wrote:

> Hi, I tried to explain everything here:

Thanks, I missed that! For RFCs it's preferable to use [Discourse](https://discourse.llvm.org/c/clang/clang-tidy/71), as there is a lot less traffic and can more easily catch the eyes of relevant people. I did not see much discussion in the original RFC though, which may hint that not many people were aware. 

My understanding is that the goal is to avoid rebuilding clang-tidy/plugins to be able to add new simple checks via .clang-tidy file. I see the benefit of this, however I'm not sure it justifies introducing this dependency from `clang-tidy` to `clang-query` in the build system. 

Do you know how much build times and binary size are affected by this change? Are there any drawbacks of this now tight coupling between clang-tidy and clang-query, from an architectural/design point of view?

I tagged @AaronBallman in the code comment but maybe it's easier to bring it up in the top-level discussion (sorry for the double ping!)


https://github.com/llvm/llvm-project/pull/131804