I would expect Xcode doesn’t have its own parser, but gets its warnings from the compiler. It, in turn, would get them from the header files. If so, the proble

I would expect Xcode doesn’t have its own parser, but gets its warnings from the compiler. It, in turn, would get them from the header files. If so, the problem wouldn’t be “not using Swift/Objective-C” or “have a different/custom custom build system”, but having a binary in your build that calls a deprecated API that the build does not build from source. That’s the case if you use a third party library you don’t have source code for, or if you use an in-house ‘library’ project (Xcode would warn you if you compiled that, but possibly not when you use it in another project, so you wouldn’t get a direct clue “rebuild that library to see the issues”).