Patch source with instrumentation without altering original code

Code
#1

I want to use libtooling to generate instrumentattion code for debug builds. I will manage to run my generator from cmake, but i don’t really know how i could patch my Instrumentation into the source without altering the normal files.

At least if i can not manage to output complete source files from my generator.

Hope my question hast not been asked too often

#2

Do you have an example of how this would work without CMake (i.e., what the command line looks like for doing what you want at all)? If not, I think this may be more of an LLVM/Clang question at first, but once it’s known how to do it outside of CMake, translating it into how to make CMake generate that information would go here.