Last I worked on llvm-c, it was supposed to stay backwards compatible. They do add new functionality but the old API should still work until llvm 4. For rust, w

Last I worked on llvm-c, it was supposed to stay backwards compatible. They do add new functionality but the old API should still work until llvm 4. For rust, while we have been broken by bad code we generated and llvm bugs, I can't recall if the API ever was changed out from under us.